MY87 5 speed running issues

emmanuelli;11536 wrote: the car never shut off on me. the main issue i ran into was the trouble starting the car right after turning it off and the throttling going up on its own from time to time when i was standing still. i was glad i have a 5spd with an auto i would have rear ended some or ran so many red lights!

I have the same symptoms and more. I'm so frustrated I can't enjoy the car. I hoping someone else would have the answer.

rluvsporsche;11267 wrote: In September 2010 with a help of friend I replaced the following oil pan gasket, motor mount, upgrade to Delrin rack bushing and replace power steering line. Since doing this project my car has the following issue high idle (1200), difficult to start (when engine hot), erratic idle, Engine hesitation (leaning out) and it turns off while driving. I have done some LH Diagnostic Troubleshooting using the WSM Vol1 D24-9. Check the following based on the following test point Engine will not start, Engine hard to start, irregular idling and Engine hesitation. This is what I tested supply voltage, idle speed contact, engine temp sensor II, air mass sensor, idle speed control activation, ground and plug connection and they came up normal. I’ve swapped MAF and LH ECU which I borrowed from Andrew Olson and Tim Murphy (great thanks to both).
I’ve replaced spark plugs and check compression. Install fuel pump pressure by permanently install a Install fuel gauge to fuel rail to have a visual when engine will not running or when it decides to stop running. Inspect fly wheel ring gear by removing the cover. None of this solved the problem.
2012 I had a Porsche mechanic R&R intake manifold and replaced all necessary hoses, TPS and gasket. I Check and adjust the timing belt. I bought an idle valve per mechanic suggestion but he has not installed it. Check and adjust the timing belt. All issues disappeared except for the high idle. After R&R of intake majority of my issue disappeared except for high idle 1200RPM. Four months have past hesitation issue returns not as often but a few times I noticed while driving.
Three weeks ago my starter failed and I had R&R starter. After replacing the starter I took the car for a drive low and behold all the issues are back except for the hesitation thus far.
I hope I didn’t confuse anyone with my rumblings. It’s been a frustrating 2 yrs. I can’t enjoy a drive fear that it will stall and will not start back up.
Thanks in advance
Ariel Trajano

To Troubleshoot this you need to start at the begining and go slow.
First thing to focus on is that you
[replaced the following oil pan gasket, motor mount, upgrade to Delrin rack bushing and replace power steering line. Since doing this project my car has the following issue high idle]

so either a vaccume hose or a wire was moved during repairs.

Then you replaced lots of parts but in your own words
None of this solved the problem.

then
[After R&R of intake majority of my issue disappeared except for high idle 1200RPM.]

So you may have had some bad hoses OR the R&R intake moved more wires.
Then after the started job issues are back.

You have a ground or wire issue!

Did you clean the 12 pin terminal on the passenger fender? Did you make sure that the large ground cable on the bottom right side of the engine was reinstalled and has good contact?

Part of the intake r&r should have completed the ISV replacement and rebuild the throttle body.

The ISV (idle stability valve) typically is a wear item that can be tested for cycling it cannot be repaired. Its impossible to access without intake removal so is normally replaced at the time.

The throttle body shaft is supported by 2 single Oring needle brearings and these Orings deteriorate and leak vacuum. Replace both bearings with the newer double Oring needle bearings.

Both the above shall require the intake to come off again.

928mac The 12 pin terminal connector appears to be crack. I'll replace that but can't find the part number in pets. I know it's a combination of female and male connector. I’m not sure which large ground wire you are referring too. Can you supply a picture please?

Does anyone know the part number?

malcolm;11547 wrote: Part of the intake r&r should have completed the ISV replacement and rebuild the throttle body.

The ISV (idle stability valve) typically is a wear item that can be tested for cycling it cannot be repaired. Its impossible to access without intake removal so is normally replaced at the time.

The throttle body shaft is supported by 2 single Oring needle brearings and these Orings deteriorate and leak vacuum. Replace both bearings with the newer double Oring needle bearings.

Both the above shall require the intake to come off again.

Malcom
I agree that ISV should have been replaced but the mechanic did not. I was pretty disappointed. The O-rings that you mentioned we tested while the car was running sprayed carb cleaner the idle increase a little but nothing noticeable. Although you’re probably right it should be replaced while the intake was apart. I'm hoping my mechanic redo the work and install ISV and O-rings.

Thanks for your input.
Ariel

On the right side of the engine and the other end attaches to the car