86 c4 running rough

[c4c5specialist]

HI there,
No, the injectors are fine electrically.

You will need to perform further diagnostics in order to validate your condition, however, if I was a betting man I would be thinking PCM at this point.

However, testing your MAF would be my next suggestion.
Allthebest, c4c5

[nram007]

how do i test the MAF sensor?

[nram007]

about a year ago i replaced that MAF sensor with a aftermarket digital one, how do i test it?

i read alot that the MAF relays go bad and alot of people place the MAF relays and the wire pigtails.

what is your thoughts on this??

thanks
nick

[c4c5specialist]

Hi there,
Well, inspection of the MAF sensor connector is the first course of action.
Using ACDelco parts is always recommended.

The wiring is as follows. You need the PURPLE wire to have 12 volts at all times when the ignition is on,l minimum.

The Black/white wire is your ground source.

Your dark green wire is your signal out to the PCM.

At IDLE, you should have about .5 volts being sent to the PCM.

Let us know whaty ou have.
Allthebest, c4c5

[nram007]

ok that seems ok.

purple wire has 16 volts only when motor is running.

green 8 volts when running.

i swapped out my MAF with a brand new one that is on loan to me and car still ran the same.
also ran the same with the MAF un plugged.

could it be a bad spark plug wire?
bad spark plug?
from a bad vaccum line??

thanks

[ChuckG]

Any way to dry out the charcoal canister, or must it be replaced?

[c4c5specialist]

HI there,
Your MAF sensor readings out to the PCM are WAY OFF!!!!

I would be next looking at your PCM feeds, both power and ground.
Also checking your ground source at your MAF SENSOR>

Allthebest, c4c5

[nram007]

i recently was able to use a snap on computer which went through my cars computer and made my car run perfect. a few things the computer showed was that the egr value is not opening and that there is a vacuum leak. also the EGR senloid/ relay was missing. where can i find one?? it seems that GM has stopped making them.

also showed my throttle position sensor is running at 56 instead of 54 and the digtail MAF sensor seems to not be reading right. Do you think that i should replace the MAF with a AC delco and re place the two relays with ac delco ones along with the pigtail which seems to be the norm for the C4??