whats the problem??Sputtering, rough idle, changed fuel filter/pump...

[knoslf]

Whats up fellas i need ur help...my 99 Yukon slt is having issues, starts up fine, soon as I put it in drive and touch the gas pedal it seems as if its not getting gas and struggling to accelerate, it takes off in spurts but acts like its being choked or something. I already changed the fuel filter and pump(Delphi pump wityh no strainer?). When I ease off the pedal it gets smoother but struggles up hill and seems like its gonna cut off at a red light. Im getting codes 102, 171, & 174. I was told the mass air flow sensor was the culprit but idk. My TB is very dirty on the backside and ive never cleaned the MAF but i did unpugg it and it still ran just as rough. Havnt changed the plugs or wires yet either. It did backfire and has a small missfire too. Where should I start? Where ca I get a good MAF? thanks in advance!

 

[knoslf]

Noone??? Well, I just took the TB off and thoroughly cleaned it with CRC Throttle Body Cleaner and it looks brand new, cleaned the MAF with CRC Mass Air Flow cleaner and when I started it up to take a test drive guess what...SAME CRAP! Can I get some input from you guys???

 

[Phone Man]

Hard to say. A MAF isn't cheap and most times are non-rufundable but depending on the miles you may want to change it out anyway. Take off the distributor cap and check both the cap and rotor and see if they are corroded.

 

[BattelWagun]

I would check the whole ignition system out, and do a compression test just to make sure its not something internally thats causing issues. But from what you've said, this may be hard to track down... The truck will run rough without a MAF input, but nowhere near that rough, and it would still be drivable. It's a possibility that your injectors may be bad too. Try to check the fuel pressure. You said it was dying, so there could be a problem with your new pump/regulator/injector assembly. Also, when you replaced the pump, did you also replace the sending unit?

 

[knoslf]

I would check the whole ignition system out, and do a compression test just to make sure its not something internally thats causing issues. But from what you've said, this may be hard to track down... The truck will run rough without a MAF input, but nowhere near that rough, and it would still be drivable. It's a possibility that your injectors may be bad too. Try to check the fuel pressure. You said it was dying, so there could be a problem with your new pump/regulator/injector assembly. Also, when you replaced the pump, did you also replace the sending unit?[/QUOTThanks for replying!..Idk, a friend installed it for me but heres the link to the pump off Amazon http://www.amazon.com/gp/product/B000CGHZ5K/ref=ox_sc_act_title_1?ie=UTF8&m=ATVPDKIKX0DER
Its a Delphi. This is becoming very disappointing as I love this truck and just want it to drive rite, seems like it got this way over nite lol. Just found out after looking under the truck that my upper ball joint is badly cracked hence the reason it shakes when I hit a bump. Gonna replace the plugs wires next weekend, im on a fixed income so a little at a time..
When u say the whole ignition system what exact parts should I consider? Also, whats the best way to clean the injectors to see if that helps?
Gonna check the fuel pressure this wek too..

---------- Post added at 08:04 PM ---------- Previous post was at 08:01 PM ----------

Will do thanks! Cleaned the maf and TB real good but issue still persist.

 

[BattelWagun]

For the ignition, check the distributor cap and rotor for corrosion or cracks. Test the wires for arcing by misting them with water while the engine is on (in a dark place of course). Check the plugs for cracked/bridged electrodes or any other oddities.

As far as injectors though, theres really no way to clean them. Sometimes just touching them will make them go bad. Seeing as the truck is 13 years old any was, its about time to get them changed anyways. They make a completely redesigned system that has done wonders for many guys chasing down nasty motor gremlins.

As I said, check the ignition, compression, and fuel pressure first though. Before you do anything. Check back with the results!

 

[knoslf]

For the ignition, check the distributor cap and rotor for corrosion or cracks. Test the wires for arcing by misting them with water while the engine is on (in a dark place of course). Check the plugs for cracked/bridged electrodes or any other oddities.

As far as injectors though, theres really no way to clean them. Sometimes just touching them will make them go bad. Seeing as the truck is 13 years old any was, its about time to get them changed anyways. They make a completely redesigned system that has done wonders for many guys chasing down nasty motor gremlins.

As I said, check the ignition, compression, and fuel pressure first though. Before you do anything. Check back with the results!

thanks I I have ordered the new plugs wires and cap/rotor since there's no telling when they've last been changed...your truck looks like mine except mine is green, same wheels and tail light covers, but i smoked mine out now though lol..

 

[BattelWagun]

They do look similar. I believe your wheels are chrome though. Mine are some crazy bare aluminum finish.(came with the ducks unlimited conversion package) I like the chrome much more though.

And new plugs, wires, cap, and rotor are a good start. Your problems may very well go away once you change those.

 

[knoslf]

Agreed, lately i've been wanting those fender flares u have but whenever i search for them all I get is the huge off-toad ones, any leads? I think they make the truck look 'classy' yet rugged. Yea my Kon came with the chrome wheels, they're 17s wrapped in 265/70/17

---------- Post added at 08:33 AM ---------- Previous post was at 08:31 AM ----------

u had your window visors color matched?

 

[BattelWagun]

The flares and window visors on mine are all OEM stuff. The fender flares I believe also came on the Z71 package, but I know for a fact that they're ridiculously hard to find. There aren't any places that steadily sell them unfortunately... (or any that I know of at least) I know LMC had some, but they were pretty expensive, like $400+... I would say just search for obs tahoe Z71 flares, they're the exact same things. And I know some of the GMT455's and 3500 trucks used them too to cover up the larger tires. But tike I said; hard to find, and even harder to find cheap.

My truck actually has the "Ducks Unlimted" package, which I don't think was very popular. It was designed with extra bits for hunters and outdoorsman. Z71 package, those flares, color matched window and hood visors, special leather interior, a gun case under the back seat, and a large black brush guard with winch mount and matching side step bars which are gone now. (BAD rust) The wheels came with it too. 16" (I think...) American Racing wheels, but with some weird bare aluminum finish. Oh, and there's duck heads embroidered freakin everywhere haha. Something like 17 throughout the whole truck...