95 G20 Van Runs Like Crap When Hot

[tardis454]

My friend has a 95 G20 van w/350. He tells me it fires up & runs OK when it's cold, but once it's warmed up it falls on it's face & stalls when you hit the gas & you have to floor board the gas pedal to get it to restart. He changed plugs, wires, ignition module, put a 'known good' throttle body & new gasket on it & it still does the same thing.

Ideas? Spidey you there???

[Bamfster]

Cat(s) .... Fuel pressure regulator????

[DanStokes]

This is a long distance guess but I'd check all of the temp sensors (or am I showing my age?). The system may think it's cold all the time. What computer codes are set? You can get a basic idea for free at any of the big box auto parts stores.

Dan

[tardis454]

Cat(s) .... Fuel pressure regulator????

I did tell him to check fuel pressure..

This is a long distance guess but I'd check all of the temp sensors (or am I showing my age?). The system may think it's cold all the time. What computer codes are set? You can get a basic idea for free at any of the big box auto parts stores.

Dan

That's the funny thing, there's no codes at all!
I was thinking plugged cat, egr, fuel pressure..
It's a nice van w/97k, he doesn't drive it very much.

[anotheridiot]

you would think there would at least be a misfire code thrown out there like the P300 I think. If its isolated its 01 for #1 etc.

Sounds like dropping the exhaust might tell you its the cats, if they are expanding and blocking the flow, but flooring the gas almost sounds like a vapor lock issue with a carburetor if the fuel is boiling in the lines. Any close proximity fuel lines to an exhaust leak or maybe a heat shield missing somewhere towards the throttle body?

[STINEY]

I'm in on the plugged cat thing.

[DanStokes]

I got thrown off the cats because it runs OK cold. Of course if he means "runs OK" = starts and idles - yeah, plugged cats will do that. Good idea to drop the pipes ahead of the cats and see what happens. That's free!

Dan

[TheSilverBuick]

Would a '95 have a mis-fire code? Isn't that still an OBDI system? I'm with Dan on swapping out the coolant and intake temp sensors as they won't likely throw a code. Followed up with as you mentioned the EGR, possibly pop it off and hose it down with some carb cleaner or something.

[Bamfster]

Yup 95 is still OBD1 ...... Good call on the temp sensors, they can be checked w/an ohm meter.

[Jimbo17]

With the motor running and your hand over the exhaust do you feel anything coming out?

I would remove the cat and try that first. One other thought would be to put one or two cans of dry gas into the tank also.

You might have just got some water the last time to purchased the gas.

Jimbo

[Mr4Speed]

I've seen the guy at the muffler shop test cats by blowing a little hole in the pipe with the torch both in front of and behind the cat to check the pressure differential.

[MR P-BODY]

I would think its the temp sensor... it controls how fat the injector
is ... when its cold its saying your on the choke and when warm it
says to lean down... seen it many times

[Bamfster]

Yea .... we need to know what the final outcome of this was ....

[AFFORDILLAC]

I had the same van, same symtoms...temp sensor.

[tardis454]

He cut the converter off, it's fine.. Changed his fuel pump, still same shit.
He's thinking ECM, I don't know.. I'll tell him about the temp sensor..