How Do I Test MAF and Wiring, Cold Start Problem

[Jerry996]

Hi,

I have a 1999 C4 (E-gas) that is still exhibiting the following problems. When first started (from cold) it idles fine, after taking off it tends to bog between 2-3000 rpm's and then the ABS/PSM warning lights come on. It then tends to surge slightly, giving and releasing throttle without moving the gas pedal. Once warm (5-10 minutes, when it reaches 180) it drives perfect. Does it no longer need the MAF after its warmed up? The code it is throwing is P0102 and 5525 according to the dealer, they remapped the DME with no change. The MAF has been replaced (no change) and I believe this means it is a connection problem to the MAF. How do I test the wiring/connector to see if/where it is losing contact? Is there a fuse for the MAF? Should I be trying something else? I have cleaned the throttle body twice with no change and run nothing but premium Chevron and have run a bottle of Techron cleaner through it with no change.

Any help is much appreciated, Jerry

[Loren]

Do your brake lights work?

[Jerry996]

Yes

[Loren]

Has the MAF been tested. P0102 says it is not connected.

[Jerry996]

No, the MAF is a new unit from Pelican. I don't believe the dealer tested it in some way. That's what I'm after, how do I test the MAF and wiring? I do not have Durametric or anything else.

Jerry

[Loren]

No, the MAF is a new unit from Pelican. I don't believe the dealer tested it in some way. That's what I'm after, how do I test the MAF and wiring? I do not have Durametric or anything else.

Jerry

Sorry, you will need the Durametric software, a PST2 or PIWIS tester to read the air flow over the MAF at idle and at 2500 RPM.

[Jerry996]

Ok, thanks for the reply. Suppose its time to invest in some durametric software, first I have to figure out how to get this Mac to run windows.

[wross996TT]

Ok, thanks for the reply. Suppose its time to invest in some durametric software, first I have to figure out how to get this Mac to run windows.

If you have a mac with intel processor, you can run parallels, bootcamp or VMware...in all cases you will have to get a copy of the dreaded windows....LOL.

I have a Macbook with durametric installed and it works great!

[Jerry996]

Update: need opinions.

The symptoms are getting more pronounced now. The surging is becoming more frequent (probably the cooler weather). Took the car to my independent to have the air bag harnesses replaced under the seats and had them diagnose my cold start/surging issues. I have new codes now, P1503 and P1506 as well as P0102. The mechanic stated that the throttle body was very noisy and most likely causing the surging and hesitating problems. He recommended the throttle body be replaced. Is that my best course of action? If I order a throttle body does that include the electronics that may or may not be causing these issues or are those transferred from the old throttle body to the new. The mechanic stated the throttle body was less than $350. This is for a 1999 C4 E-gas. Is this something I should do myself? Thanks as always for any help given.

Jerry

[Loren]

Yes, you can do it yourself.

Why would you replace the throttle body if the codes say throttle jacking unit (which attaches to the throttle body)?

[Jerry996]

Yes, you can do it yourself.

Why would you replace the throttle body if the codes say throttle jacking unit (which attaches to the throttle body)?

Well I didn't know that the "throttle jacking unit" attached to the unit. thought maybe it came with the throttle body if replaced as a whole. Which is why I posted the question. All the mechanic told me was that the throttle body was extremely noisy and possibly needed to be replaced. Could the noise be from the jacking unit? Could both need replacing? Is the jacking unit serviceable? If you can send me a part number then I'll order the jacking unit and see if that does it?

Thanks, Jerry

[Loren]

You don't see many worn out throttle bodies. Unless it was damaged I doubt the (metal) throttle body is bad.

I would get a second opinion.

[Jerry996]

When you say "throttle jacking unit" does that mean throttle position switch (996-606-116-00-M14) or something else? I can't seem to find a part named throttle jacking unit.