928s4forme

Mongo,

You are right big brother. Unless you have the plugs out, it'll be hard to turn by hand. You were right, the grounds at the rear on the engine cleared most of my troubles, except for the warm start issue. I've got it narrowed down though to the harness between the battery and the alternator. Will sectionize further and let you know.

She's running great now, so long as I don't shut her off and try to start it right away Give it 15 minutes and she'll start up again..... Only thing left is the AC and the warm start issue... And then I can run around town with her while I rebuild the original one this fall/winter...

Mongo

Oh and another thing. I may have missed it, but did you get your alternator tested? I had issues on a 944 that had slow cranking when warm as well. The alternator wasn't doing it's job charging the battery. I know the 928 eats alternator brushes. This could also be a potential symptom.

Another thing too is have you inspected the wiring harness to the MAF sensor?

My car would not hold an idle too when warm and here's what I found:

Mongo

Another test I did when I was having similar issues was to disconnect the battery, disconnect the O2 sensor, then reconnect battery and drive the car for about 10 miles up and down a local road doing between 45-60 mph. Even when the LH was running in open loop mode, which is default when no O2 sensor is detected, the car went into limp home mode where it started running like **** due to an issue with MAF wiring. This was very tricky and literally took 11-12 months to track down!

Landseer

Time to measure the endplay properly and report the number.
That's missing from all this grandiose troubleshooting.

Mrmerlin

Yep what Chris said ^^^^^
I am withholding any more suggestions till I see some numbers,
The check also includes making sure the rear drive shaft pinch bolt is also tight

Mongo

Still no endplay measurement????

I would just measure it man. Or at least loosen up the pinch collar bolt. If the clamp flies back, it's obvious there was major preload on that flexplate. Pry with a screwdriver on the flywheel. If movement is seriously noticeable, the motor is done. You could just buy a shortblock somewhere and throw your cylinder heads on it after draining all the oil out of the bad block. I am of course assuming worse case scenario.

mickster

+928,000.

928s4forme

Allright guys...give me till Sunday and I'll get you some endplay measurements...promise. I just got a new battery today for my digital caliper and will get some numbers on the board for you....

Landseer

Hard to capture with a caliper. HF has an endplay gauge cheap.

Hoping its not the issue.

Podguy

Do you have a reference number of the HF tool. Thanks

928s4forme

Hey Guys,

As promised, I have done the flex plate check and here are the stats:

When cold:

measurement from pinch bolt to end of the grooves on the TT before pinch bolt tension release: 16.90 mm

after tenison release 12.89mm

measurement of crankshaft endplay at flywheel when cold with long screwdriver pushing the flywheel aft: 0.04mm total (from a zero position before releasing flexplate tension)

What I found: The pinch bolt was not torqued to spec. Torqued it to 66ftlbs. I believe the darned "flexplate creep" caused the hard start issue when warm.

After I torqued the pinch bolt, I ran the engine until it warmed up and checked it again. We are good to go.

The hard start issue is completely gone. The engine idles great cold and warm. The engine starts at all temps now.
The only issue I have now is that when coming to a stop sometimes, she will occassionally stall (only happened twice while on an hour long "victory" drive).

I may have a fuel delivery issue. Could be my fuel pump starting to act up (original to car)...

Not sure, will be checking pressure at the rail tomorrow...

What do you guys think?

928s4forme

Update,

I let the car hit and heat sink for a little bit and came back to start and she started up great and idled great. When I put her in either R or D, she stalls unless I lightly press the accelerator to even her out and she'll idle fine after that...your thoughts please? She is idling right now as I type this...

Mrmerlin

you didnt mention if you checked the rear driveshaft pinch bolt,

if you didnt check it then your not finished with the job.

SO you might start over,

release the front bolt,
then remove the rear bolt,
then inspect the rear bolt ,
add a drop of blue loctite to the bolt,
then install it,
torque to 66 ft/lb,
then install the front pinch bolt with a drop of blue loctite.
NOTE pry the flywheel back prior to tightening the pinch bolt.

I would also venture a guess that your oil is full of small metallic particles and that a few 500 mile oil changes with fresh filters might be in order.
To find the metallic s take a lamp cord and fit it down the dipstick tube,
then drip the oil onto some black cardboard,
then look at the oil in the sun with a magnifying glass .

NOTE the reason to not use the dipstick for this is because every time you put it into the hole it grinds off small metallic particles

I think before you go off looking for other issues,
you need to start paying attention to the answers that your given

Mrmerlin

also your reported numbers dont make any sense a 0.04mm is 0.0015 or just under .002 thousands.

the nominal wear on the Thrust bearing is from 0.008 to a max of 0.016 inches
or 0.20 to 0.40 mm

if your misreading the numbers thats easy to fix,
if infact these are the numbers you seeing it would be best to recheck them as the clearance your seeing is less than it should be so new main/ thrust bearings are probably going to have to be fitted

928s4forme

MrMerlin,

I feel chastsized right now. Nevertheless, I will do as you ask because it makes perfect sense and I didn't take into account the rear flexplate. Unfortunately, we will have to wait till next weekend.

Is there anything else I should be looking at?