Brett Matthews

Hi Jeffrey,
I did that test as well, and in my case, no gas out the vacuum port. No fuel smell, either.

Luc G.,
Your problem now is certainly oposite of mine. I was lean, you are rich! Over rich in fact! Not having had this experience, I have to back off. Few clues to offer you....
Talk to Rich off line, he knows about the LH!

I think the stock muffler has some more back pressure, than a RMB?

oups59

This is what I have done so far.

- I checked the pressure regulator and the two pressure dampeners for traces of fuel. No traces. OK

- I changed the fuel fuse #42. OK

- I changed Relay XXV LH-Jetronic Fuel Injection. OK

- Checked MAF connection plug. Clean . OK

- Checked Distributor caps and rotors. Clean. OK

- Checked spark plugs wires. OK

Try to start it. Same results. It is still running rough than it stop. But when I tried the restart it, it will not start at all.

I re-checked everything. No spark from the plugs

I changed Ignition Relay #IV. Spark OK

It still won't start !!!

What should I do next ??

Rich9928p

If you don't have spark, or there are intermittent failures, check the inductive engine position (RPM) sensor. I have the instructions on my website.

The connections to the spark modules (plastic covered modules in front of the radiator) are also known to get corroded and cause problems - a definite thing to clean and inspect.

Also, the quickest way to "bypass" a bunch of potential trouble spots is to jumper the relay sockets (30 to 87) for the LH, EZK and fuel pump relays. If it starts, then either a relay is bad (the one you plug back in and it doesn't start) or there is a problem in the related circuit to that relay.

Last but not least, a defective LH module will cause too rich of a fuel mixture. But, if the EZK is not providing the engine RPM signals, you will not have fuel injection.

oups59

I also inspected and clean the connections to the spark modules. Plus I verified the temp sensor II. No problems there.

jeff jackson

Oups, old buddy...in your original post...you said you had used a "Stabilizer" in your full tank of fuel. What brand was it ?? Do you recall ? Perhaps this, or poor/degraded fuel quality is somehow responsible. Is it possible for you, to drain the tank down, and add some fresh premium gas to the remnants of your "stabilized" gas, and give it a try that way...Seems to me, if all was fine prior to your "laying her up for the season"...the only thing thats changed...was the addition of the fuel stabilizer, and your last fillup. Just guessing here...but stranger things have happened with these cars.

oups59

Rich,

I tested LH and fuel pump relays ( use the horn relay to confirm) - OK
I tested power supply through EZK relay (terminal 18 and 29 on EZK connector) - 12 volts OK

It looks like the LH is dead. But I didn't hear the fuel injection valves click when the ignition turned is on and engine is not running but engine will not start, spark plugs are dry and the ignition system produces spark.?

I will re-check the fuel pump, fuel filter and valve this week-end just to be sure

Jeff,

To be honest, I don't remember.

Brett Matthews

Hey Luc G.,
I saw that you had checked relay XXV, did you check XX? ( Fuel Pump ) XVI? ( EZK Ignition System ) And just a thought, did you check your O2 sensor? Just shots in the dark.....

oups59

Brett,

I did not check the O2 sensor yet.

Brett Matthews

Luc G.,
In my '87, Rosy, I found the O2 sensor plug, down in the bottom of the fuse panel area, under the lower wooden bolted in panel. The wiring loom from the sensor enters from somewhere along the passenger side of the tunnel, routes itself under the carpet, and up into the fuse panel area. This MIGHT save you a little time, trying to find the plug?

Have you seen/read about an alternate to the Porsche supplied O2 sensor yet? ( IF you happen to need another one )

AFARR

Sounds a bit like my Car's problem.

Fuel pump was getting intermittent power from a bad (oxidized) ground in the hatch area. Check that. Hook a multimeter to the fuel pump and turn the key (couple of long wires with aligator clamps are excellent for this) and check it out.

AFARR

oups59

The LH was check by John at JDSPorsche and it is OK

I will buy a timing light this week-end and recheck the ignition system.

Robert Ellis

Luc,

So what was the final out come of the start then stall?
My car is doing the same thing. really rich exhaust smell, black smoke, rough running.
Things I have checked/ replaced

plugs bosh platinums
nology wires
MAF
cap,rotors,
temp II sensor
LH unit checked and swapped.
Ignition controll monitor relay bypass

I'm running out of ideas and my shark still doesn't run.

HELP

Robert

oups59

Robert,

I am still searching !!!

I did not receive my LH from John yet. Probably next week. I waiting for my fuel pressure gauge (from 928 Motorsports) as well.

I did change
-the spark plugs (bosch platinum)
-The caps and rotors

I will change my O2 next week-end.

Let you know if I find a solution.

Robert Ellis

Luc,

I changed all of the plugs today and each plug had heavy black fouling and smelled like fuel. The plugs were dry though not wet. Two of the plugs had lots of oil from the valve cover on the porcelin.

Still runs rich and rough. Now I need to replace the valve cover gaskets and might as well the intake gaskets and all vacuum lines etc. I think I should replace the wire harness as well.

I am running the Murf SC kit as well.
keep me posted in your progress.

Robert

oups59

I got my fuel pressure gauge from 928Motorsports last night. I just try it and the fuel pressure is at 3.8 bar (around 50 PSI) so it is OK.

But then it drops to 20 psi in lest than 30 minutes.

So it may be the fuel pressure regulator or a leaky injector or the fuel pump holding valve.

Still searching