Need help… Crank/no start + Really bad MPG

[rockola1971]

Just throwing this out there... check the rotor and cap if you haven't yet.
My '99 would start maybe crank an extra rotation but start on the first try. What got me looking though is driving the back roads, going up hills at 40 - 55 mph it would buck like the TCC was disengaging/engaging very quickly. It would also do it at 70 mph on the highway if enough load was placed on the drive train. Kept thinking it was the transmission. MPG was down a bit maybe but not alarming. It also seemed to have a rough idle, a little more vibes than what I remember. So I looked in my maintenance log, plugs had around 40K but the wires, cap and rotor were original with a bit over 200K on them. When I pulled the cap off, all 8 posts were covered in powder and the end of the rotor was corroded and burnt. Don't know how it was even getting a spark AND there were NO codes. No more bucking under load, starts better and will see what the mpg is after a couple of tanks.

You must have had the 5.7L vortec Vin R engine. All LS engines do NOT have a distributor, cap or rotor starting with very first one in the late 90's The Corvette and Camaro LS1. In 1999 you could buy a new GM truck/suv with either the 5.7L or a LS Family Gen 3 V8 depending on whether it was the old body style or the new body style (for that generation overlap era). I had a 99 Sierra Z71 Vin R with a 5.7L and if you went and asked parts for a 1999 GM Sierra Z71 you would get parts for the newer body style (like the 2000 model year). You had to ask for parts for a 1999 K1500 Z71 which get you the old body style parts. Most of the parts were Not intechangeable, especially engine and suspension parts. Ever tried to stick a 350 chevy water pump on a 5.3L engine? It will NOT work. They arent even close to being the same and the tire rods are nothing alike between the new and old body style.

 

[frydaddy96]

Thanks Rock, good info! Yeah, it's the 5.7 Vortec.

 

[Rayyy]

I would replace the fuel filter and see what the fuel pressure looks like both key-on engine off, and engine running.

On my 2004, there is no exterior fuel filter, apparently it is inside the gas tank.

Does that means it’s part of the fuel pump? Or is it deep inside there separate from the pump?

 

[Doubeleive]

On my 2004, there is no exterior fuel filter, apparently it is inside the gas tank.

Does that means it’s part of the fuel pump? Or is it deep inside there separate from the pump?

It's part of the fuel pump they changed them after 03

 

[Fless]

On my 2004, there is no exterior fuel filter, apparently it is inside the gas tank.

Does that means it’s part of the fuel pump? Or is it deep inside there separate from the pump?

On a 2004 it would have an external fuel filter if the engine was Flex Fuel. Otherwise it's only a sock on the pump (inside the tank).

 

[OR VietVet]

I had 2 problems. One was the long crank before start, intermittently. If turned KOEO and waited 3-5 seconds, there is no long crank before start. I did replace the fuel pressure regulator for that because I could see a very slight "clean spot" on the regulator body where it looked like fuel was leaking out and cleaning that area. I did a couple other tests for the problem that I stated earlier and decided that the fuel pump is losing the pressure. The pressure never drops below 15 psi when I had a gauge on it for 4 hours. I am convinced it will need the pump. The mpg has not been checked because it has never been out for a "trip", per say. It is strictly around town as a run around items gatherer and used because of the convenient rear hatch.

The other problem was that during an engine crank to start, the cranking would just stop-like the battery was dead but it is not. I have checked for connections, corrosion, voltage drop and all tests good and this problem is very very intermittent. I am convinced that the problem, well known problem for these rigs, is the ignition switch. I knew about this problem when I bought it and when I went looking for a new switch replacement, the only thing available was the aftermarket Dorman or Standard Parts switches and I installed the SP switch and all was fine until recently. Mind you, the intermittent problem I have now was never experienced with the original switch that I swapped out and I actually still have. I did finally find an AC Delco D1426D switch and should have it in my hands by the 29th. It is literally a 15 minute labor time install.

If either of these problems would just fail completely, I could diagnose and know exactly what is wrong. I will get there for sure. I will not give up.

I was able to go thru O'Reilly's and get an AC Delco D1426D ignition switch and replaced it and actually did a video of that and have it up at you tube if anyone is interested. The very intermittent "stop" cranking problem, that only happens after is already cranking but has not started yet, is not fixed. later that day my girl was out and about and it did it again. So, now I have two apparently good ignition switches for this rig and the same switch fits up to 2009 TrailBlazers and other GM vehicles as well. The ones I have are the grey panel, updated contacts, designs. When this rig was bought in December of last year, it was stated as a well known weak spot for these TrailBlazers that the ignition switch contacts were crap. The old design was all black part housing. The updated ones are grey panel housing. I did not want to take a chance so I bought the only available ignition switch at RA that is a Standard Parts aftermarket part with the grey panel. I had never experienced the intermittent stop cranking problem but was trying to be pre-emptive. After the aftermarket part was installed, the intermittent stop cranking problem showed so I assumed it was the aftermarket part and eventually found the ACD part at O'Reilly's. The initial one I took out to replace with the SP switch was already grey panel but I had the new part in hand and went ahead and replaced. I installed the ACD part and still have the problem. I am convinced I have a voltage drop problem but I have not experienced the problem when I am in the vehicle and she only experiences the problem when away from home. I did inspect the cables at the battery and starter and all are completely clean and tight. I need to get it to stop cranking, hold the key in the crank position and check for voltage drop problems. I suspect a failing starter solenoid now but want to be sure. each and every time it has stopped cranking, if she cycles the key, it always starts, so far.

 

[Donal]

Sounds like the solenoid contactor ring is just about burned out from arcing. I think starting with low amps at the starter over time causes this condition. May have been a previous owner may have not maintained the battery. Check the hot cable to the starter if you can access it. I have done crazy things like running a welding cable from the positive batt to starter lug to see if I could get improved cranking performance.

 

[OR VietVet]

Sounds like the solenoid contactor ring is just about burned out from arcing. I think starting with low amps at the starter over time causes this condition. May have been a previous owner may have not maintained the battery. Check the hot cable to the starter if you can access it. I have done crazy things like running a welding cable from the positive batt to starter lug to see if I could get improved cranking performance.

I should have said this already. It is a brand new Interstate battery. I will recheck the battery and alternator as well.

 

[Rayyy]

I was able to go thru O'Reilly's and get an AC Delco D1426D ignition switch and replaced it and actually did a video of that and have it up at you tube if anyone is interested. The very intermittent "stop" cranking problem, that only happens after is already cranking but has not started yet, is not fixed. later that day my girl was out and about and it did it again. So, now I have two apparently good ignition switches for this rig and the same switch fits up to 2009 TrailBlazers and other GM vehicles as well. The ones I have are the grey panel, updated contacts, designs. When this rig was bought in December of last year, it was stated as a well known weak spot for these TrailBlazers that the ignition switch contacts were crap. The old design was all black part housing. The updated ones are grey panel housing. I did not want to take a chance so I bought the only available ignition switch at RA that is a Standard Parts aftermarket part with the grey panel. I had never experienced the intermittent stop cranking problem but was trying to be pre-emptive. After the aftermarket part was installed, the intermittent stop cranking problem showed so I assumed it was the aftermarket part and eventually found the ACD part at O'Reilly's. The initial one I took out to replace with the SP switch was already grey panel but I had the new part in hand and went ahead and replaced. I installed the ACD part and still have the problem. I am convinced I have a voltage drop problem but I have not experienced the problem when I am in the vehicle and she only experiences the problem when away from home. I did inspect the cables at the battery and starter and all are completely clean and tight. I need to get it to stop cranking, hold the key in the crank position and check for voltage drop problems. I suspect a failing starter solenoid now but want to be sure. each and every time it has stopped cranking, if she cycles the key, it always starts, so far.

Have you checked the fuel pressure on yours?

Mine would also start when cycling the key or leaving it on ON for a few seconds before cranking, but when I measured my fuel pressure at the fuel rail, it was dropping super quickly even when cycling the key, not holding prime at all.

I replaced the fuel pump yesterday, Bosch part# 67567 purchased at Home Depot for a great price (yes, you read that correctly, Home Depot!)... and my rig has been starting first try every single time, even cold start and after sitting overnight. No more crank/no start so far.

I also installed all four O2 sensors to boot, hoping this and the fresh pump will help get my MPG back up to normal. I'll update after calculating a few tanks in case anyone is interested.

 

[OR VietVet]

I was able to go thru O'Reilly's and get an AC Delco D1426D ignition switch and replaced it and actually did a video of that and have it up at you tube if anyone is interested. The very intermittent "stop" cranking problem, that only happens after is already cranking but has not started yet, is not fixed. later that day my girl was out and about and it did it again. So, now I have two apparently good ignition switches for this rig and the same switch fits up to 2009 TrailBlazers and other GM vehicles as well. The ones I have are the grey panel, updated contacts, designs. When this rig was bought in December of last year, it was stated as a well known weak spot for these TrailBlazers that the ignition switch contacts were crap. The old design was all black part housing. The updated ones are grey panel housing. I did not want to take a chance so I bought the only available ignition switch at RA that is a Standard Parts aftermarket part with the grey panel. I had never experienced the intermittent stop cranking problem but was trying to be pre-emptive. After the aftermarket part was installed, the intermittent stop cranking problem showed so I assumed it was the aftermarket part and eventually found the ACD part at O'Reilly's. The initial one I took out to replace with the SP switch was already grey panel but I had the new part in hand and went ahead and replaced. I installed the ACD part and still have the problem. I am convinced I have a voltage drop problem but I have not experienced the problem when I am in the vehicle and she only experiences the problem when away from home. I did inspect the cables at the battery and starter and all are completely clean and tight. I need to get it to stop cranking, hold the key in the crank position and check for voltage drop problems. I suspect a failing starter solenoid now but want to be sure. each and every time it has stopped cranking, if she cycles the key, it always starts, so far.

Much thanks for @TollKeeper that introduced me to GMTNation Forum when I purchased this 2002 TrailBlazer. This video I did for you tube explains how I eventually fixed this intermittent no cranking problem: