pmaskale

I have had the truck for about 15 months, with no problems. Last night it started fine, and I drove it about 7 miles. I tried to start off from a red light, and the truck stalled when I gave it gas. After many attempts to restart I was able to get it running by holding the gas pedal to the floor while cranking. After that, I could keep it running if I kept the RPM around 2K or above, but it had very little power. I limped it to a friends house.

This morning it started right up and ran rough until it warmed up. Once warm it will Idle smoothly around 1K. When I give it gas it wants to stall. The only way to rev the engine is to smash the pedal to the floor very rapidly (the RPM dip and then raise up). As long as I can keep the RPM up by keeping pressure on the accelerator the truck will run with pretty normal power.

Other Notes: It was colder than it has been in a while here (about 35 degrees), and I hadn’t run the truck for about 3 weeks prior to last night. Truck has 160k miles on it, and there is no check engine light.

I will start testing and replacing things. I will keep updating this thread as the story progresses.

Thanks for reading this. Any educated diagnosis would be appreciated?

farmer12

I think I would get hold of a fuel pressure guage and see what its doing...sounds like its not getting enough fuel when you hit the throttle.

wde3477

Welcome to the site!

Does your check engine light work - that is, does it self-test when you start up? Just want to be sure that we aren't dealing with a failed lamp.

One thought is that the throttle position sensor (TPS) may have a problem - but this usually throws a CEL. Perhaps read the computer codes for grins to see if anything pops up - always a good place to start, IMO.

Fuel supply could be another issue - pump, filter, or return/bypass valve could be causing pressure problems.

Just call me Sean

iTrader: (1)

Check the computer for codes, instructions are at the top of this section. The check engine light doesn't have to be on for there to be codes.

pmaskale

Thnaks very much for everyones input, and welcome. By the way, that was my first fourm post ever. The check engine light does "self test". I did not know that there could be codes with no check light. I will work on checking those.

Because the plugs got really fouled (due to the stalling, and age), I am currently replacing them. I also got an IAC valve that I will probably put on.

I should have it done by tonight (after 9hr of work & 3hr of class I might not make it). I will get back to you guys with the possible codes tomorrow.

By the way, after I turn the truck off there is a humm/buzz noise coming from the back of the engine. I never heard it before, but it may have been there. I have a stethoscope, and will try to use it to see if it is comming form the fuel regulator.

swampfishin

Has the fuel filter been changed lately? If it hasnt then it could be your culprit. As they suggested, pulling codes tells you alot.

pmaskale

Good news, the picture is getting a little bit clearer. I replaced pluggs and IAC, which did nothing. Then I removed the EGR, and blanked off the intake hole with a rubber cork. After this the truck still ran like ****. Then I replaced the fuel filter and the symptoms got a lot better. The truck no longer wants to stall all the time now. I drove it all around, and the only problem was a realy high idle.

After the drive I connected the EGR back up and the truck only starts with the pedal to the floor, then it just wants to die all the time while running. I am sure that I have been dealing with a multifaceted problem. The fuel filter and EGR are big pieces.

Does anyone have any input on getting the rusty EGR pipe(from the exhaust) off the bottom of the valve. I have been shooting it with PB Blaster once a day for the past 4 days. Still can't get it off.

Any input about pipe removal or general advice is welcome. Thanks All.

pmaskale

Well, I thought I would update this thread so that future trouble shooters will be able to get some closure on this issue.

After Fuel filter, Plugs, IAC, MAP and EGR replacement I finally found the real problem. It ended up being the $15 engine temperature sensor located next to the distributor. This sensor was bad and, according to the voltage measurement, was telling the computer that the engine block was at 32 degrees F all the time. It only took about 20 min to change it out, and the truck was back to normal.

In hind sight all the symptoms made sense. Realy rich smelling exhaust, stalling on mild acceleration, and the fact that it started fine when cold(it was January and around 32) but ran horribly when warm. There was no Check engine light, but there was a code(21 I think)

The only issue now is a slightly low idle, and very occasional missing/stalling. I will get working on that tonight

Just call me Sean

iTrader: (1)

21= engine coolant temperature sensor out of range. Could have saved a lot of time and money if you posted the code right away.