Gas Cap

[busbo]

okay..here it goes:

1990 351 auto

i recently had to replace my gas cap and i've encountered a problem (or two). after starting, she wants to die. i can only keep it running by giving it lots of gas. when i shift into drive and give it gas it hesitates bad. does this ring any bells? thanks!!!!!!

 

[Ziggy]

Did you use the proper gas cap? Some gas tanks use "unvented" gas caps. If you install a "vented" gas cap, the system does not work right. My GTI is fuel injected and uses an "unvented" gas cap. Guess it helps build pressure up in the tank and deals with fuel delivery and emissions. I know they test the caps when they smog vehicles and if it doesn't pass, you have to replace the cap and start all over again.

 

[busbo]

so the new gas cap did nothing. i can't find a vacuum leak anywhere. i've changed the TPS and MAP sensor. i took the EGR valve off and cleaned it but it didn't seem to do anything. anybody have any more ideas? i greatly appreciate it.

 

[Ziggy]

O2 Sensor, they should be changed on a regular basis. Or your cat is AFU'd.

 

[busbo]

your cat is AFU'd.

i wouldn't doubt it!!! i will try the O2 sensor and pray that's it.