Hey Folks, have an interesting problem on a vehicle I haven't worked on in 20 years.

I have an issue keeping the vehicle running. No codes in the computer at the moment and the problem is that when started I get no throttle response.

If I step on the gas hard, it stalls, floor it and it stalls. If I gently increase the throttle it will stay running, I can get it up to 2K 3K 4K rpms and it will run forever, no issues, but when at idle it will run a little then stall and if the gas is pressed normally, it won't rev up, just fall flat on its face.

Its been a long time working on something this old but I remember the MAP Sensor causing similar issues, especially on Chryslers, so I swapped it out and it didn't make any difference.

I am thinking it may be a problem with the TPS or IAC but wanted to check with you guys before proceeding.

Any feedback is appreciated!

 

what engine, how old is the gas, and when was the last time it ran?
it could very well just be old gas.

 

Fresh fuel. It will run fine when the throttle is slowly pressed, no misfires, sounds strong. It will idle for a little bit just fine also but then bogged and stall.

 

what engine?

 

7.5L EFI

 

Maybe a bad fuel pressure regulator? Pull the vacuum line off the fuel pressure regulator and see if you have/smell gas in it.

 

I'll check that, but strange how I can get it to rev up if the gas is pressed slowly. I can get it to run at 2 3 and 4K RPM steady just takes a while to get it up there.

 

Fuel is definitely flowing. Without the vacuum line should I see/hear a difference?

 

on a pressure gauge you should see a difference.

 

Fuel is flowing out the vacuum line?