Hesitation at high RPM's

[Ghostrider 310]

Tommy, no dis intended, in fact you're right in the hood and yeah it's been Noah's Ark. I always heard AZ would do free code reads but I never had to run the test. The other poster might be right spark plugs could be a great guess. Let me know if you need something, I can't lift but I can guide you through a lot of jobs including the plug tubes and plugs if necessary and I have a great set of tools including many of the Porsche specialty items, a Bentley manual and hours of wrench time on 1998 986.

PS Whose wrenching on it? Avoid Cantech unless you like paying 125% more than any job should cost.

[tommy583]

Ghost, no dis taken. I agree with you on Cantech. I went there once, never again. I have been taking it to Upstate Imports in B'ville. I might have to take you up on your offer to help one of these days.

[Ghostrider 310]

George at Fehlman bros is pretty good on Porsche cars if you hit the wall at the other place, as for the simple stuff just let me know.

[tommy583]

Well I think I have found out where the chirping sound is coming from. With Ghost Rider's help, as he did most of if not all of the work. One of the spark plugs was loose. Tightening this plug has reduced the noise by at least half. I hope when we get time to do the other side, the noise will be gone altogether. Thanks Ghost!

[Ghostrider 310]

Tommy, I think i have a shorter allen in house for that job, that's why it was easier last time. All we have to do is check what plugs are left and that should do it.

[tommy583]

Well I got around to tightening up the plugs on the passenger side. The front plug was about 1/4 loose. No more chirp! I'd like to thank Ghostrider for his help as well.

[tommy583]

OK update. The chirping noise has been solved. It was a loose plug. The hesitation at RPM's over 5,500 is still there sometimes. I stopped by an Autozone on the way to work. There were no codes using the ODB II scanner. Now should I just buy a Durametric or would an Indy have a scanner that would work.
To refresh the situation the car has new plugs, fuel filter, air filter,AOS and belt. The indy that put in the plugs said the coil packs look good. I have never had a check engine light come on. I have run 5 or 6 tanks of gas since the car was taken out of storage. It did the same thing last year before i put it in storage.
From the input i have received from you guys so far i still need to check fuel pressure, MAF and maybe O2 sensors. Thanks

[Overdrive]

Considering what you have left to check and what's been replaced so far, it's a pretty safe bet that your hesitation issue is somewhere on the fuel end of things. But do check out your MAF and see if it's filthy, it could be that it's dirty enough to cause some issues without throwing a CEL, but I'm betting it's fuel delivery related.

[tommy583]

Well on the ride home from work the car ran great. It's around six miles to the hi way on ramp. So the car was nice and warmed up before i got to it. I took her to 5 grand in first, 5,500 in 2nd and 6 grand in 3rd. No hesitation. 65 deg outside temp. Got on it in 1st and 2nd when i got off of the hi way. Still good. With a cooler outside temp i would think that it's not a fuel pressure issue. Cooler air is more dense, so i would need more fuel to have a good burn? I'm going to clean the MAF to see if that helps. I'd rather try that for the cost of the spray before I pay to get the codes read. Good idea? Maybe there is some oil in the intake from when my AOS failed?

[Overdrive]

Originally Posted by tommy583

I'm going to clean the MAF to see if that helps. I'd rather try that for the cost of the spray before I pay to get the codes read. Good idea? Maybe there is some oil in the intake from when my AOS failed?

Oil in the intake is possible, even very likely if you never actually went in there and cleaned up after the AOS failure (did the AOS full-on fail or was it on its way out?). I'd say get in there and check your throttle body and the intake plumbing for some oil, and give it a good cleaning if you find any.

No harm in cleaning the MAF before going with a replacement, but I'd recommend buying one anyways and having it on hand so that you can replace it when the time eventually comes. Pelican Parts is where I got mine from. Also, whether you clean the MAF or not, go get the car hooked up to a scanner anyways, might as well give it a good once over since you've yet to do so. It can't hurt, right? Small expense for a gain in knowledge, even if it ends up telling you everything's ok.

[tommy583]

The AOS was on its way out so i changed it last fall. I never did clean the intake or the MAF. I think i will do both this weekend and see if it helps. If not i'll have to take it to the shop next week and put it on the scanner.

[Syracuse986]

Originally Posted by tommy583

The AOS was on its way out so i changed it last fall. I never did clean the intake or the MAF. I think i will do both this weekend and see if it helps. If not i'll have to take it to the shop next week and put it on the scanner.

What ever came from this Tommy?

[tommy583]

I found the carbon canister to be clogged solid. I ordered a used one from Woody. I blew out the lines with compressed air and installed the the new canister. Hesitation gone and no more CEL.