Rough idle

[creepin']

Help

I have a 92 Comanche big ton with a 4.0 6 cylinder. I have been chasing a problem with it idling rough, it started last year with it starting hard and then a rough idle and it would just randomly shut off sitting at a light. New parts- fuel pump last year, map sensor, tps, iac, fuel filter, cps, o2 sensor.

tested fuel pressure 32psi at idle and jumps to 40psi when the vacuums line is removed from the pressure regulator. 

PLEASE HELP ANY IDEAS

[HOrnbrod]

Check for fault codes.

 

https://comancheclub.com/topic/28111-reading-obdi-91-and-92-mj-fault-codes/

[creepin']

I don’t have the check engine light coming on will it still show a fault code?

[omega_rugal]

clean the inyectors? TPS out off adjustment

[creepin']

How to you clean the injectors?

i don’t it would believe the tps is out of adjustment the brand new one is in there just the same and the problem is still the same.

[HOrnbrod]

2 hours ago, creepin' said:

I don’t have the check engine light coming on will it still show a fault code?

 

Yes. At least 90% of fault codes never trigger the CEL. Do this before anything else.

[creepin']

Ok I cycled the key on and off and did not get any codes from the flashing check engine light on the information center. Will a scanner show more codes than that will?