nile13

Alex, my issue seems to be that starter spins and engine but doesn't catch. Which results in a very weird sound after about 6-7 seconds, almost metal on metal-like.

However, I've done some Rennlist reading and a number of people pointed to FPR. The suggestion was to part-way press the throttle pedal before hot restart. Seems to work, which, I think, does point us to FPR, right? I just didn't have a chance to dig into it deeper yet. It could be the fuel pump check valve. What I wanted to isolate is that it's not the starter. Am I correct in my assumption? What bugs me is that weird sound.

vincer77

Have we determined if the starter is only spinning, or if the engine is cranking over? If the former, could be the bendix drive on the starter.

Ed Hughes

^^Exactly^^

nile13

In my case the engine is spinning. Not sure about OP.

IXLR8

From reading this, it sounds like you have two issues; the starter not engaging properly or at all and the other is a guess without connecting a fuel pressure gauge at the port on the driver's side fuel rail.

Onto the starter, without hearing it, I would be guessing. But a metal to metal sound if it is the starter gear teeth spinning against the ring gear on the flywheel, I would remove the starter ASAP and inspect. I care less about the starter gear, but I would care a lot about the gear on the flywheel. Lets hope it is the clutch in the starter drive.

A fuel pressure gauge will confirm pressure readings at ignition on and with the engine running as well as pressure retention after shut down. Its an easy test if you have a fuel pressure gauge or if you can borrow one.

nile13

Alex, the car does start every time when the problem I've described presents itself an I simply push the gas pedal part-way and turn the key again.

Now, the noise is weird. it's not there right away. I turn the key, the engine turns over and tries to start, doesn't catch and about 4-5 seconds later I hear this noise. I thought that the tooth might be stripped on the starter or the flywheel, but that doesn't seem to be the case based on starts with part-way pushed gas pedal and the fact that this only happens when the car is hot. The noise is more high pitched than anything else.

I don't have a fuel pressure gauge, need to look into that. But should probably simply replace FPR first, the car is at 98K miles or so and almost 20 years old now and it's a $55 part. If I do borrow the gauge, how do I attach it? I know very little about fuel delivery system.

IXLR8

There is a fuel pressure test port capped off by a brass cap on the fuel rail.

The brass cap is a one time use item (supposedly) and is available from Porsche.

Vorsicht

Your local Autozone (or similar parts store) will let you borrow one for free. They charge you the full price when you get it and then give a full credit when you return it.

Fortuna

I found this on the scheme cap. Under it painted valve. What is this valve?

Dplus

Oops! You're right; my mistake.

nile13

OK, interesting. So if I attached the pressure tester to the rail, what should I look for, in detail?

the way the issue had been explained previously is that FPR starts leaking and the engine, essentially is flooded hen how. Thus it either needs to dissipate extra fuel or need part throttle to start. Interestingly, it's not really related to being hot, though it seems like it. At least that the couple explanations I've found on Rennlist and so far empirical evidence of part-throttle starts taking care of the issue seems to be jiving with this theory.

Fortuna, поменяйте регулятор давления топлива. Он недорогой и вполне может помочь.

vincer77

If the problem is a leaking pressure regulator, then measuring pressure may not show you anything. SOunds like changing the part is a good idea.

Does the noise sound like an electric motor i.e. the starter turning but not engaged? Is this sound only heard when the engine doesn't start?

nile13

Yes and yes, I would say.

vincer77

Maybe you have 2 problems.

But it is odd that you get the nose 4-5 seconds after. My bendix is failing so what happens is that when i try starting the motor that the starter spins without cranking the motor and i hear a ping sound when ii stop. Usually one or more tries will allow it to engage. This only happens intermittently, maybe 5-10 times in the past year.

Can't see how a partial throttle would fix this. Replacing the FPR first sounds cheaper than replacing starter.

jskylarwilson

I had this happen on a 964 Race car years ago. Starter would turn over, but engine would take forever to start. I put in a new starter, and the car worked perfectly. I swore that it wasn't a starter problem because it sounded like it was working perfectly fine, but the starter ended up being the problem.