Help - running rough, new plugs, wires, cap and rotor

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

steamroller

Full Access Member
Joined
Apr 10, 2010
Posts
361
Reaction score
1
Location
The South
Has the distributor gear been checked yet? Known issue for them to get knife edged and cause problems, alot of times it's just on 1 side of the gear.
 
OP
OP
gulleyman

gulleyman

Full Access Member
Joined
Jun 21, 2010
Posts
277
Reaction score
2
Location
TX.
Unless something was disabled in your pcm codes would have been thrown for a malfunctioning oxygen sensor...
I did have a performance programmer that I used but I restored the factory programming after the tune-up didn't fix it.
Seems to me you are treating symptoms here. The same parts are replaced over and over with the same results.
You are SO right, if you only knew how pissed I was that the dealer came back at me with cap, rotor and AC Delco plugs LOL but sunlitcomet was right, the plugs were fouled there was crossfire in the cap and they had to start somewhere...
There are other failures that can contribute to running too rich. The comment about being intermittent at first is an important clue.
I agree, seems like this will ultimately point towards the origin of the problem
I would be looking towards things like the MAF (Mass Air Flow) sensor and the MAP (Manifold Air Pressure) sensor. Even the IAT (Intake Air Temp) sensor. Seems like you go into a failure that causes all 8 plugs to come out black. Oxygen sensors are a possibility, but they would seem to want to fail one at a time rather than all four at once.
Can these be tested with an ohmmeter or something? If I can test them rather than the dealer it will no doubt be more cost effective.
If you have a lot of miles, could be wiring degradation, possible broken wire. Know it’s a pain to do, but checking wiring between these above mentioned sensors and the ECM, while moving the wires as much as possible might be a cheap test.
Mileage is 145,771, the first mechanic said he tested them but I can't say for sure how much he moved the wires while he did it :(
And then there is the distant long shot of run-a-way, fuel pressure. The ECM has no way of knowing what the fuel pressure is.
Lost me again there bub, I'm learning a LOT here on this forum :D
So before you order up a replacement engine, might want to do a little testing on these sensors.
Agreed, show me the way :D can I test these sensors with an ohmmeter or something or are they cheap enough that I should replace them just to rule them out?

I am still racking my brain and tech info still but when the fuel spider was replaced the pressure regulator should have been eliminated as the culprit and I would believe that if there were frayed wires by now something would show up as an computer error. The computer is capable of a lot of detailed info. And without the software and interface to access it it will be that much more difficult.
I'm with you there sunlitcomet, I think the first mechanic, although he was limited, ruled out most of the "usual" problems.
My post is too long, gotta split it up...to be continued...
 
OP
OP
gulleyman

gulleyman

Full Access Member
Joined
Jun 21, 2010
Posts
277
Reaction score
2
Location
TX.
Gulley could you possibly post all known codes you had pulled in case you missed any on previous posts as well as anything else that may seem weird with your truck even if it does not sound engine related?

---------- Post added at 07:53 AM ---------- Previous post was at 07:43 AM ----------

Including anything installed before it happened.
You got it:
I bought the truck in Minnesota, drove it around town for a few months then cross country to North Carolina. It lost the transmission in Wisconsin. So I towed it to a dealer and had the transmission replaced, then paid to have it shipped to me in Texas (cost me a fortune).
It came with a Hypertech Performance Programmer and a remote start alarm, I put the "middle of the road" tune on it so it got better performance but still used regular unleaded fuel. Put about 25k on it with no problems.
I had the exhaust replaced from the cats back because there were leaks, they never went away and I can't keep a hanger on the left tailpipe to save my life, keeps rusting off.
The starter went out on me, I ended up replacing the starter, battery, power and ground wires before fixing the charging problem.
I installed an aftermarket cold air intake, didn't seem to affect the performance one way or the other, sounded cool though.
I can't remember if it had been intermittently running rich before or after the issues with the charging system or the installation of the cold air intake.
I also tried to install an electric brake controller and shorted my brake lights, took a loooong time to figure that one out because I have never finished installing the brake controller :doh2: Once the brake lead was removed from the frame the brake lights worked again. I'll have to try that again after the truck is running right.
It was running strong even though it would run really rich and smell like a rolling gas station from time to time.
Eventually it started to sound like it had a slight miss at idle. I took it in a couple of times to Autozone and O'reily when the CEL was on, kept getting a P0306 code, they both told me I'd be due for a tune up soon.
When the CEL came on and stayed on I started saving for a tune up. Before I thought I was ready to do it the truck started running REALLY rough and the CEL was blinking constantly.
Took it to O'reily again and had them scan it, same P0306 code. So I bought the plugs wires, cap and rotor and replaced them. It got me home running a little better but still not right. Found out that one of the wires was defective and returned the set for Bosch Premium wires, all the plugs were fouled so I replaced them again too. (you can read all about that in the first page of this thread)
Then I took it to a mechanic, he got a "P0300" and "P1345 A" code, said it was misfiring on five and seven at idle, then when RPM's get between 1500-2000 they start firing again but then we lose number six.
Then he:
Pulled the distributor and checked it
Re-adjusted the timing
R&R Injector spider w/ new improved MFI
R&R crank and cam sensors
Checked all the wires to and from the ECM with an ohmmeter
R&R ECM
Checked compression,
Checked the sweep (for TPS failure)

I took it to the dealership who told me it was the cap, rotor and plugs, so I swapped them with AC Delco parts, still the same issue.
Last week I did the Seafoam treatment hoping for a miracle, got a serious smoke storm in the backyard, runs a "little" better but still a hard miss and CEL is blinking constantly.

I guess from what I have read in this thread, it’s time to start thinking outside of the box....I’m suggesting mostly taking some test meter readings of the components are could affect mixture. MAF, MAP, IAT and a simple check of the fuel pressure to answer the that question.

Also the comment that this all started intermittently should be analyzed further.
Just sayin………………
Agreed, can I do that myself with an ohmmeter?

O2 sensors should be able to be backprobed to read voltage so doing that could help decide a fork in the road as far as the other sensors go.
Yup, can I do that myself with an ohmmeter?
I just eliminated the pressure as a probibility because the old regulator went out with the old spider.
Sweet :)
I would eliminate any alarm/starter modules if running rough while truck is not moving or the if the modules are reoriented in axis only.
You lost me again sunlitcomet, what does "reoriented in axis only" mean? LOL
Maf, Map and Tps can be tracked to what is known as performane or range problems when they don't coincide.

The Iat and Engine coolant temp. (ECT) sensor does not have such a direct error code.

There is a code for insufficient coolant temperature for closed loop ops that would eliminate the ECT in my opinion as if was given feedback for a hot engine or a direct high or low stalled reading.

A malfunctioning Iat does not have a performance variable code but under obd2 can be diagnosed with the help of monitoring egr activity and feedback voltage.

So that is likely a candidate for backprobing based on that the others could report performance problems and up to now haven't.

As far as the inability to cut the pulse width I will for now side with rich bank codes indicating that for now.

I do believe that there is more then just"expected problems".

If you really get into the data and understand theories of operation of the components used and how they interact with other known givens you can extract unexpected problems not dreamed up as well.

I believe the answer is in the data I just can't see his data other than what he reports.

I hate the fact that I am broke right now and can't get the interface and software I want for my own truck right now. I can work on stuff like this for at least a full day or longer and forget to eat or sleep.

I will break for a moment.
Wow, I think you may have just explained how to test those sensors but it went right over my head! I feel like a chicken in an Algebra class :confused:
Gully, do you know if if the cam correlation error showed before or after the crank sensor was replaced?
Both if I understood the mechanics explanation, that's why he replaced it.

Thanks Jonathan, great OBD2 info. I only do Tec3, so I can only guess.

I totally agree. It’s hard to diagnose a truck with a unknown history, that has gone through three sets of plugs and wires and distributor caps in a short time.

I understand the FPR's were changed with the injectors, but I would still check the fuel pressure just in case the return line is plugged down stream.

The error codes need some interpretation sometimes. Like a miss in certain cylinders does not exactly say, your wires are crossed, even though that is what was wrong.

I think the intermittent occurrence during the onset is still one of the big clues.

There is likely to be more than one component contributing to this mystery.

Can a loose timing chain or skipping a tooth cause late firing which would not totally burn the fuel, leaving the plugs fouled?

It would be nice to have a wide band sniff the tail pipe……………
Don't know if the fuel pressure has been checked.
The error codes have stayed the same when the wires were crossed and when they were not,
guess that just means that those cylinders were dead anyway?
Don't know if the timing chain was replaced before I bought it with just over 100k.
What is a "wide band sniff"?

That is why I was asking about when the cam/crank correlation problem showed. You can get false misfire codes after replacing the crank sensor. I am kind of leaning to a problem in the drivetrain. I would have thought Gulley would have picked up on a unusual noise from there by now.
The only unusual noises I've noticed are exhaust leaks and the typical GM fuel pump whining, doesn't sound like it's dying but it's definitely louder than my Lexus and Nissan fuel pumps, sounds just like the Caddy I owned last year. Hope that helps...ran out of room again, to be continued...
 
Last edited:
OP
OP
gulleyman

gulleyman

Full Access Member
Joined
Jun 21, 2010
Posts
277
Reaction score
2
Location
TX.
Well then, it looks like it’s time for Shane to step up and do some more testing and get back to us with the results…………….
:D Sorry for the late response guys, been sick with the flu and broke too. I was gonna take it to another mechanic or back to the dealer but I can't afford it right now so it's just sitting in my back yard driving me CRAZY! Hopefully we can figure this out so I don't have to spend what little money I can scrape up on another mechanic :(

Check that ECT sensor.

The ECT can throw a indirect fault code that a sufficient temperature could not be reach for closed loop ops. or direct one for a short or open circuit but he has not reported one yet.

bass1775/ sunlitcomet, what's an ECT sensor? LOL I feel like I'm back in school again...

99Yuk asked if any one said anything about bent valves, valve guides, or valve seals yet? He said that in his truck two cyls misfired randomly but he had other symptoms like the plugs would foul every week, and he'd go through a liter of oil a week, etc.
I don't drive very far anymore and it does use some oil periodically between oil changes. Sometimes it's three quarts low and it doesn't seem to be dripping. The oil level is fine at the moment, it doesn't look milky at the dipstick (it didn't at the mechanics either but he said he saw some inside the motor when he changed one of the sensors) My coolant looks good at the radiator cap but is barely visible in the resiviour. Could that be a bad thing? My Dad also mentioned that I might have to have the valves, guides and seals checked at some point too...
Has the distributor gear been checked yet? Known issue for them to get knife edged and cause problems, alot of times it's just on 1 side of the gear.
Yup, had the first mechanic check that.

Hope that gives you guys some more insight on this beast, thanks to all of you for sticking with my uneducated butt this far! Your help is much appreciated :waytogo:
 

SunlitComet

OBS Jedi-Do Good
Joined
Sep 30, 2010
Posts
16,206
Reaction score
187
Location
unknown at this time.
A multi meter can be used yes but not every connector is gouing to let you stick a probe in there without damaging the connector(pigtail) seal.

Higher fuel pressure with all other variables fixed would cause more fuel dumping out the injectors creating a richer mixture.

ALarm theory was based on info below:
------------------
Bulletin No.: 02-06-05-004b

Date: February 14, 2006

INFORMATION
Subject:
Misfire DTCs P0300, P1380, P1381 and Catalytic Converter Damage Due to Installation of Alarm Systems

Models:
2006 and Prior GM Passenger Cars and Light Duty Trucks
2006 and Prior HUMMER H2, H3
2006 and Prior Isuzu Light Duty Trucks

Supercede:

This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 02-06-05-004A (Section 06 - Engine/Propulsion System). General Motors Engineering, in an effort to determine the root cause of catalytic converter damage, has determined that aftermarket alarm systems incorrectly installed in vehicles have the potential to cause misfire codes and damage to the converter. These alarm systems use a circuit interrupt which utilizes the ignition circuit on the vehicles.

These alarm systems utilize mechanical relays and normal vehicle movement can trigger these relays to engage and disengage the ignition circuit while the vehicle is in motion. These disruptions of the ignition circuit, which occur in milliseconds, may cause more fuel to be commanded. Overtime, this dumping of fuel on and off again can cause misfire codes and ultimately damage the converter assembly.
Important: Engineering could not identify any alarms that utilize solid state circuitry that would eliminate this concern. Because of this, it has been determined that all alarm systems must be routed through the starter circuit in order to avoid this condition.

Dealers must be aware of this issue and take note of the wiring on vehicles with alarm systems that come in for repair, particularly for catalytic converter damage that seem to have no known root cause.

-----------------

My thought was depending on the design of the relay that they sensitive to g-force(speed bumps, rough roads and such)that the alarg ignition interrupt might chatter causing intermitent ignition or injector glitchs.

What I ment by orientation by axis is that if you were to for example take a home electrical circuit breaker in your hand held it up right with the switch in the closed(on not tripped) position and bang it down on a solid object parts inside would react to the g-force and cause it to trip it self. If you did the same thing again but held it sideways it may not do it becuase the parts cannot pivot the same direction as before to same gforce direction. Hence if you reorient the alarm from being layed out flat to being upright in postion or vice versa that kind of problem could be prevented. But becuase the vehicle is still when parked I don't think it would apply.

Taking a breath....

Check these ground straps for damage and such when you have time, maybe got damaged when the tranny came out:

G101 Sheet Metal at RH front Wheelhouse
G102 RH front of Engine Block, near Damper Pulley
G103 RH front of Engine, near Thermostat Housing
G104 RH top of Cylinder Head, near center
G105 RH front of Engine Block
G107 LH front Fender (Auxiliary Battery Ground)
G110 RH rear of Engine Compartment, below Heater Lines Gill RH rear of Engine
G112 RH front of Engine Compartment, below Underhood Reel Lamp
G113 On Radiator Support, near LH Headlamp
G150 (VIN M, R, J) RH front of Engine, near Thermostat Housing


ECT = Engine collant temp sensor

DESCRIPTION
The engine coolant temperature sensor is a thermistor (a resistor which changes value based on temperature) mounted in the engine coolant passage. Low coolant temperature produces a high resistance 100,000 ohms at -40°C (-40°F) while high temperature causes low resistance 70 ohms at 130°C (266°F).

OPERATION
The VCM supplies a 5 volt signal to the engine coolant temperature sensor through a resistor in the VCM and measures the voltage. The voltage will be high when the engine is cold. The voltage will be low when the engine is hot. By measuring the voltage, the VCM calculates the engine coolant temperature. Engine coolant temperature affects most systems the VCM controls.

The scan tool displays engine coolant temperature in degrees. After engine start-up, the temperature should rise steadily to about 9O°C (194°F) then stabilize when thermostat opens. If the engine has not been run for several hours (overnight), the engine coolant temperature and intake air temperature displays should be close to each other. When the VCM detects a malfunction in the Engine Coolant Temperature (ECT) sensor circuit, the following Diagnostic Trouble Code (DTC) s will set:

* DTC P0117 circuit low.
* DTC P0118 circuit high.
* DTC P0125 excessive time to Closed Loop.
* DTC P1114 circuit intermittent low.
* DTC P1115 circuit intermittent high.

The above DTCs contain a table to check for sensor resistance values relative to temperature. Refer to Specifications. See: Computers and Control Systems\Specifications

The Mass Air Flow (MAF) sensor measures the amount of air which passes through it. The VCM uses this information to determine the operating condition of the engine, to control fuel delivery. A large quantity of air indicates acceleration. A small quantity of air indicates deceleration or idle.

The scan tool reads the MAF value and displays it in grams per second (gm/Sec). At idle, it should read between 5-7 gm/Sec on a fully warmed up engine.

Values should change rather quickly on acceleration, but values should remain fairly stable at any given RPM. When the VCM detects a malfunction in the MAF sensor circuit, the following Diagnostic Trouble Code (DTC) s will set:

* DTC P0101 system performance.
* DTC P0102 frequency low.
* DTC P0103 frequency high.

Intake air temp.
PURPOSE
The Intake Air Temperature (IAT) sensor is a thermistor which changes value based on the temperature of air entering the engine.

OPERATION
Low temperature produces a high resistance 100,000 ohms at -40°(-40°F). A high temperature causes low resistance 70 ohms at 130°C (266°F). The VCM supplies a 5.0 volt signal to the sensor through a resistor in the VCM and measures the voltage. The voltage will be high when the incoming air is cold, and low when the air is hot. By measuring the voltage, the VCM calculates the incoming air temperature. The IAT sensor signal is used to adjust spark timing according to incoming air density.


PURPOSE
The Manifold Absolute Pressure (MAP) sensor responds to changes in the intake manifold pressure. The pressure changes as a result of engine load and speed. The map sensor converts this to a voltage output.

OPERATION
A closed throttle on engine coast down would produce a relatively low MAP output voltage. A wide open throttle would produce a high MAP output voltage. This high output voltage is produced because the pressure inside the manifold is the same as outside the manifold. The MAP is inversely proportional to what is measured on a vacuum gage. The MAP sensor is used for the following:

* Altitude determination.
* Ignition timing control.
* Exhaust Gas Recirculation (EGR) diagnostic.
* Speed density fuel management default.



Wide band sniffing is a smog test with tailpipe probe that is capable of measuring various exhaust gases at a wide range(1-100%) instead of narrow range(say 1-50%)

Something to that effect.

High oil consumption with no dripping can indicate it is being burned in the cylinders thru busted head gaskets or valve seals. If it was big enough to see out a tail pipe it would probably burn all the time at any speed if it were gaskets. If you WOT (wide open throttle) and let it close and saw oil burn during deacceleration only could be valve seals. If it leaks outside it could be hidden if it drips onto hot components(exhaust manifold while running).

top that and your coolant reservoir to the suggested level marked on the container and keep an eye on them.

You could probably ignore the look of the old crank sensor. It is supposed in a dry area but oil residue and condensation can get milky.

Thirsty...
Milk does a body good. Especially at a rate of 1/2gallon+ a day

The seems like a lot of oil lost between changes without external leaks.

In case I missed it how are the plugs fouled. Oil? black sooty? colored deposits?

Can you post pics?

At this point it might be wise to save when you can for a good scanner that can do a memory dump to post readouts here. It would provide all the sensor data for analysis. I hate to see you keep spending on parts. I still have more details but enough for now:sleepy:
 
Last edited:
OP
OP
gulleyman

gulleyman

Full Access Member
Joined
Jun 21, 2010
Posts
277
Reaction score
2
Location
TX.
...In case I missed it how are the plugs fouled. Oil? black sooty? colored deposits?

Can you post pics?
Yup, I'll try to get some tomorrow.
At this point it might be wise to save when you can for a good scanner that can do a memory dump to post readouts here. It would provide all the sensor data for analysis. I hate to see you keep spending on parts. I still have more details but enough for now:sleepy:
At this point I'm tempted to do it just to see if you can pull a rabbit out of your butt....what was the name of the one you recommended and how much do they cost?
 

SunlitComet

OBS Jedi-Do Good
Joined
Sep 30, 2010
Posts
16,206
Reaction score
187
Location
unknown at this time.
Well I do have a big butt so prospects are good.

If you want a great self contained unit that provide an excellent start for the new user I reccommend the otc 3111. $264 at amazon. Usually higher at ebay. http://www.otctools.com/products/obd_2_can_abs_scan_tool_code_connect Scroll to the bottom of page and you will see some links to a pdf brochure aqnd video. On the last page of the brochure there is a comparison of that and three others. It does offer abs coverage but not transmission however if it reads all obd2 data as claimed I would think it would cover the p codes it should get some trany info. I think it reffered to not getting acces to tranny dtc 2 digit codes. The 3499n is $413 at amazon but will get the tranny too plus coverage for OBD1 live data for domestic and some foriegn too.

I have not gotten a scanner my self yet bet rest assured as you probably have seen here that I put dozen off hours into research in the things I do. I spent over 100 hours alone on research of service manual, forums, and tech data just to replace my tv.

I will get the 3499n eventually as well but I am probably going to start with that other package I mentioned before since I have an unemployed(me too:emotions122:) laptop and I'd have a bigger display with so much more info and costumizable displays and management of data. And I can mount a laptop for other uses in the cab for $250. For me to much is never enough.

Call me a fat geek but I would like to build a diagnotic desk with that stuff, gas analyzer, electrical load testers, pressure equipment, old style ossiliscope screens and meters that used to be around. Best of both analog and digital. I may work on aircraft but I can really whip up some fasinating projects for many things old and new.


A home theater example: http://www.sunlitcomet.com/images/home/agoraquest.jpg I still use Minidisc, Laserdisc and super VHS.
 
Last edited:
OP
OP
gulleyman

gulleyman

Full Access Member
Joined
Jun 21, 2010
Posts
277
Reaction score
2
Location
TX.
Hey sunlitcomet, I have a carputer that I plan to install in my truck (once it's running right) it would be cool to have OBD II built into it. I've installed a couple already but not with OBDII because I don't know anything about it. This website offers a bunch of options for that purpose, some are even "open source" and probably free. I'm sure you could use them on your "unemployed laptop". At first glance it looks like they might already have wireless OBDII adapters too. Could you check this out and help me figure out which one would work best for our trucks?

http://www.mp3car.com/vbulletin/eng...stics-etc/?daysprune=-1&order=desc&sort=views
 
Last edited:

SunlitComet

OBS Jedi-Do Good
Joined
Sep 30, 2010
Posts
16,206
Reaction score
187
Location
unknown at this time.
The only thing I see open source is hardware for which you still have to pay for(materials)and and for software something that describes codes But no progress on obd software yet. That same web sight has a store link that is selling the same stuff I mentioned on post #47 on page 5 of your thread here. Maybe $15 cheaper on total of the three parts. The package components I chose was about $320. I think it will be more complicated to deal with then a handheld tool if you are very new to obd stuff but if you are willing to dive in then go for it. If you already have computer in vehicle that it will work with then it is worth taking a shot at if you really want to start getting into computer/vehicle systems integration. If you have the computer permanetly then wireless is not required IMO. I would think you may want to choose an interface cable with angled conectors for a more clean fit if it is always going to be plugged in.

It might be like a crash course for you.
I still stand by this stuff or a handheld like an OTC scanner for us. What is your preference. I am still aways a bit from having the money for mine.

---------- Post added at 08:53 AM ---------- Previous post was at 08:36 AM ----------

I looked again at the wifi/bluetooth option and that is only from the interface box to computer you still have to plugin the box to vehicle with the six foot cable which you can get with an angled plug for $3 more. Unless I can find a interface boxthat is a direct connect on the truck connector that stays out of the way with wifi to the computer I will stick to the cable with an angle. That would assure that I can use my wifi modem on puter for something else perhaps for a mobile hot spot system There are plenty of usb ports on mine already. On my laptop is that all the connenectors on on either side but I am sure I could neat them up if I use that mount I mentioned before.
 
Last edited:

99Yuk

Full Access Member
Joined
Sep 28, 2009
Posts
1,080
Reaction score
14
Location
Northern Ontario, Canada
...A home theater example: http://www.sunlitcomet.com/images/home/agoraquest.jpg I still use Minidisc, Laserdisc and super VHS.
A pic is worth a thousand words, and I have a thousand questions...

1) Holy Remote Hell! So I'm thinkng that you obviously try to use a universal remote for that stuff. I'm curious to see what your research came up with to resolve that issue? An Ipad/Iphone with an IR attachment and the Remote App? How about a windows Media Center IR Blaster with a custom remote software on a touch screen tablet? Or just a plain vanilla universal remote? Do tell how you manage that beast...

2) I counted six Linksys by Cisco products. Six? Damn. Please tell us what each one does.

3) Finally, what Model # TV did you end up buying? Just curious. I'm shopping for another one myself for my bedroom. If another Geek has already done the research, you know it's gonna be good. What was your criteria wish list for tv shopping?


EDIT: BTW, maybe wait until 2Q 2011 for the car comp. There are supposed to have some really good small win7 tablets out by then. I'm thinking of an acer 5" maybe 7". Then hook up to ODBII and Audio, etc. I'm seriosly considering something like that next spring when I resume modding my truck. I'd like to see a 5" touchscreen tablet mounted in the 1.5 DIN space. Maybe have to move the heater controls, but who knows.

EDIT 2: HAHAHA I just showed my wife this pic and told her that's what I'm gonna have. She's like all, 'No way, that's just another geeks dream!'..... sigh... so no remote hell for me...
 
Last edited:

Forum statistics

Threads
132,181
Posts
1,863,559
Members
96,686
Latest member
MrsMfcknMcDonald

Latest posts

Top