shiva1

Sounds like good advice. Thanks again for the input.

Mrmerlin

do some searching for crank end play or flex plate . I second the flex plate check as the next most important thing to be done , and its not complete unless the rear pinch bolt is also inspected for tightness.

pcar928fan

The 35 year Porsche mechanic who has worked on half a dozen (or even 50) 928's isn't touching my cars for sure! There are precious few GOOD 928 mechanics out there and fewer still who follow the amazing technical info here on this forum!

shiva1

Thanks again guys for the education, I do indeed appreciate the wealth of knowledge from this website. It takes alot of anxiety out of the ownership experience.
PS Mmmerlin. Nice P51 D, K,H? (Humble cherokee 235 pilot)

John Speake

Cost would be $ 80 USD for the pair. There may be someone on RL who can blow a pair fro you. The bin files are available on the net.

You would need to check that your mechanic has the less common 12 way rectangular plug on his Porsche tester lead, which was only used on MY88.

I would seriously consider buying a diagnostic tester of your own if you plan to keep the car. If you can fault find and do some mechanical work then 928 ownership will be much more rewarding, personally and financially :-)

shiva1

Thanks John, I'll put that on my now fast growing "to do"list. Almost had you do the rebuild work on my LH unit, but decided to go more local with Loren at Sstems Consulting. You have a great website -great info on EZK/LH/MAF relationships, troubleshooting starting problems. Your posts always get my attention.

John Speake

Thanks for your kind comments. Well, my main agent for LH rebuilds in the USA is Louie Ott, also in OR, wasn't that local enough ? :-)

shiva1

Hi John, it wasn't until I joined Rennlist that I became aware of Louie. Prior to that I took the recommendation of my mechanic. Actually got on Louie's site last night to check it out. Once I get my idle problem addressed I'll be saving my spare change for perhaps some performance goodies. Tried the WD40 treatment. The car will idle fairly well until it warms up. Then after about 5-8 minutes starts rpm searching(although not as wide of swings as before WD40) motor dies consistantly after about 60 seconds of idle.

John Speake

If the rpm are hunting around, then that indicates all is well with the ISV, the closed throttle switch and the part of the LH that contains the idle loop circuits.

If the problem seems to start when water temp is getting near normal running temp, that may suggest a problem with the O2 loop which is activated at that point. Before that the LH is effectively runnin open loop, defaulted to the mid point of the adjustment.

shiva1

Hmmm....crossing my fingers but think the battery disconnect I did might have fixed the idle issue. Motor now idles rock steady at 650 rpm when motor is warm, no movement of tach, oil pressure or ammeter needles, nor rpm searching. I'll find out for sure when I take it out tomorrow in the daylight hopefully not in the pouring rain. Much thanks to John S. for his time and expertise. Next question...can this be a long term fix or is is the problem destined for sure to come back. Some one posted that they drove the car for several thousand miles after this fix and then the problem reoccured. Your input please....

Randy S.
'87 S4 /Automatic
RMB/ 95000 miles

2000 Audi A6
4.2

WallyP

Randy,

Regardless of what your mechanic thinks or says, you need to check the flexplate, and sooner rather than later...

shiva1

Wally, you got my attention. I respect your wealth of knowledge. I will address this matter ASAP. I don't think I can get under my car to do it-don't know how with only a floor jack and 2 jackstands. What should a reasonable price be to have it done and cost of new clamp? Guess I'll pretty much park it until I can get it done.Thanks for caring-I had absolutely no idea of this issue until being a Rennlister.I'm grateful for it. It's great to find so many that truly love the cars as I do.

86'928S MeteorGrey

A floorjack, 2 jackstands, and a dial caliper with a magnetic base is all you need. (well besides basic ratchet, sockets, wrenches, and a torque wrench) When you remove the lower bellhousing cover for the first time, you may need to drop the front portion of your exhaust to get at two of the bolts on the cover. When you reinstall the cover, leave the two bolts that can't be removed without dropping the exhaust out. It will make subsequent checks of the flexplate EASY. I pray you aren't experiencing TBF. Do yourself a huge favor and don't start or drive your car another inch without releasing the flexplate tension. If endplay (crank fore/aft play) is under around .015" you are ok. If not, you can cry on our shoulders, because believe it or not your engine could be TOAST. If it checks out ok, immediately use one of the known fixes. The best method is a Constantine clamp from Black Sea R&D. This clamp requires removal of the torque tube for install, and isn't always convienient. The next best alternative is the PKlamp from Porken... It's available through Roger at 928's R Us. It can be installed without major surgery. The third method involves lock tite and additional torque, but with as serious an issue this really is for the automatics, I'd spring for the PKlamp at the very minimum. If your mechanic has no urgency to check the flexplate, he is NOT a competent 928 mechanic, and I wouldn't trust him with your car. It could be that he is competent, but needs to be schooled on this issue ASAP. Good luck with your diagnostics. And welcome to the tank!

mickster

Hi Shiva,

I don't doubt either your mechanic's experience with your car or his overall competence but I doubt he works on as many 928s as the people giving you advice and as many of the problems are age-related, he may not have seen these problems.

A good mechanic is open to ideas and suggestions. One less confident or more arrogant (or both) is not.

I do know that some of the top 928 mechanics come here all the time to read (even if they are not contributors like Sean and Greg and such) and get help/ideas.

Good luck!
Michael

ErnestSw

Way down under the MAF there's a connector for the crank position sensor. In my 91 the connector had become brittle and fallen apart. That could cause an intermittant fault and result in your symptoms. Just one more thing to check.