1989 Dodge Ram 250 Van - 5.2L Idle Surge

[crownvic]

I have a 1989 dodge van with a 5.2,the idle surges up and down then shuts off as if it has a vaccum leak.

Fuel pressure is good i smoked it for vaccum leaks found egr was leaking.I replaced it but still same problem. It smells like it is running rich, kinda burning my eyes if it runs too long. customer has replaced the map sensor, idle speed control and the tps readings seem to be ok.

[brianp87]

what are the fuel trims?

[steven kiser]

check vac supply to map.......

[crownvic]

The vaccum to map sensor is good,but it seems like if i have it plugged off it runs fairly better.

[GRAND MARQUIS]

I think the PCM is gonna be your problem

[Tim Martin]

Before you replace the pcm connect a lab a scope to the o2 sensor and check its pattern. That may reveal the problem.

[steven kiser]

i seem to remember that there was an issue of crapolla getting into the vac tube to the map. within a short time it would trash the sensor. i'm starting to remember an issue with the vac amplifier to the egr. i thing that when you purchased an egr from the dealer they included an updated version where you had to make modifications.

[fortknoxx]

i seem to remember that there was an issue of crapolla getting into the vac tube to the map. within a short time it would trash the sensor. i'm starting to remember an issue with the vac amplifier to the egr. i thing that when you purchased an egr from the dealer they included an updated version where you had to make modifications.

we had something similar here. we found when the sensor was not replaced in a timely fashion the pcm would be searching for a signal on that curcuit that was not there, hence it would overload the pcm, by it working so hard searching for a signal. just replacing the part would not fix all of the trickle down problems caused by lack of maint.

[liljoe]

What have you figgures out on this truck? We would like a little feedback please, Thanks.....

[steven kiser]

still thinking it's an egr issue.............come on, you're killing me here i need an answer. just pull that vac line off the valve and see what happens.

[crownvic]

Sorry,i had to go out of town.I just got in this morning,it was one of the injectors in the throttle body.Thank you for all your help!Have a bless day!

[Tim Martin]

At the risk of sounding like a self praise person, that is why I suggested scoping the O2 signal cause it would a shown an injector running rich. But if you were able to figure the solution without a lab scope that is good.

Good going for ya!

[brianp87]

what are the fuel trims?