Help Please! Won't go past 45Mph when hot.

[heyok]

Yesterday I was driving through the mountains and it was about 100F. I approach a hill and add a little gas to maintain my speed and things start to go weird. It was as though it was starving for gas!?! The further I push the gas pedal, the more it would hesitate and choke. Backing off the gas would make it run fine. As long as I didn't try and exceed a certain amount of "gas flow" it would run perfectly. When I made it over the hill, the truck would speed up, but only to a certain point and it would seem to be starving again.

All the gauges were in normal positions, but after about an hour of driving and nursing it along, the check engine light came on.

I parked in the shade for about 15 minutes to let things cool. Then I could drive about 10 minutes before it would act up again.

Does this sound like my fuel pump is acting up, or maybe I am having what someone described as "vapour lock"?

I'd appreciate any ideas.

Thanks,
Al

 

[Rhett]

No, probably not vapour lock--that's pretty uncommon on fuel injected engines.

Check the code from the check engine light, that will help you a lot.
It sounds like an O2 sensor problem to me. Find out what check engine code you're getting and post here.

 

[paul99explorer]

Could it possibly be your coil pack breaking down? Usually this will occur with extreme heat. I think mine's going bad, and it happens only under load..and much worse in extremely high temperatures.

 

[heyok]

Thanks for the replies. I'll try and get the codes read tonight.

Al

 

[heyok]

A friend of mine is a mechanic at a gas station. He connected his Snap-On scanner to read the faults. I don't know all that he saw, but I saw something about both banks being lean. I told him that I didn't have this problem before I installed a throttle body spacer... I just didn't connect the fault to this. He took the plastic cover off the top of the engine and sprayed some carb cleaner around the throttle body spacer and he found a vacuum leak! The gasket on the engine side of the spacer had a very small hole. He explained that any air getting in that doesn't go past the MAF can cause the air/fuel mixture to screw up. A little bit of silicon over the hole seems to have things fixed!

I gave him a case of beer!

 

[gratebig1]

i would think catalytic converter. try drilling it out

 

[Billy177]

i would think catalytic converter. try drilling it out

why ruin a perfectly good converter if that is not the problem there are easy ways to test them to see if they are plugged up