944 Starts but does not run

[Mike_T]

1984 944 Starts but does not run.
I put the car away for winter and now I'm trying to awaken it but it doesn't want to run. The engine turns over and immediately starts, then it dies. It's as if it's not getting air or fuel.
I have monitored to pulses to the coil. They continue for a short time after the engine smothers. The tacho shows about 900 rpm for the two seconds it runs. These signs tell me that the ref. mark transmitter and the DME are probably working. If I monitor the fuel pump and relay, the relay engages as the key is turned, the fuel pump runs the engine starts, dies and then the relay drops out and of course the pump stops.
There is plenty of fuel flow to the engine and I have changed the fuel filter.
Other things checked:
Airflow sensor and temp sensor voltage/resistance as per spec
Air filter is good.
Vacuum when starting is about 20" Hg.
Spark is at the plugs and they are clean and correctly gapped.
Fuel pump relay rings out okay.
The exhaust is clear (no obstructions).
It is rust free with clean electrical connections and only 58k miles on the clock.
The timing belt has only a few thousand miles on it.
When I put the car to sleep for the winter, it had about 3/4 of a tank of fuel. I added fuel conditioner and fuel deicer. The fuel is a bit old but I siphoned some and it burns fine in other motorized equipment. I added a few gallons of fresh fuel for good measure.
Can anyone suggest something other than "the hook". I can't bear to let others see the car being towed to the service center.
Thanks
Itchy to hit the road in Toronto......

[asidrave]

Mike, im having the same exact symtoms with my 84 944 after i installed the clutch. i checked everything you named. im puzzled as well. let me know if you find out whats wrong. thanx, Raul

[Dave's 944]

Have you checked your fuel filter. Its possible it could have been clogged. That and make sure your pump is developing enough pressure.

------------------
If you drive it, Race it
Dave
'87 944

[Mrmerlin]

Originally posted by Mike_T:
1984 944 Starts but does not run.
I put the car away for winter and now I'm trying to awaken it but it doesn't want to run. The engine turns over and immediately starts, then it dies. It's as if it's not getting air or fuel.
I have monitored to pulses to the coil. They continue for a short time after the engine smothers. The tacho shows about 900 rpm for the two seconds it runs. These signs tell me that the ref. mark transmitter and the DME are probably working. If I monitor the fuel pump and relay, the relay engages as the key is turned, the fuel pump runs the engine starts, dies and then the relay drops out and of course the pump stops.
There is plenty of fuel flow to the engine and I have changed the fuel filter.
Other things checked:
Airflow sensor and temp sensor voltage/resistance as per spec
Air filter is good.
Vacuum when starting is about 20" Hg.
Spark is at the plugs and they are clean and correctly gapped.
Fuel pump relay rings out okay.
The exhaust is clear (no obstructions).
It is rust free with clean electrical connections and only 58k miles on the clock.
The timing belt has only a few thousand miles on it.
When I put the car to sleep for the winter, it had about 3/4 of a tank of fuel. I added fuel conditioner and fuel deicer. The fuel is a bit old but I siphoned some and it burns fine in other motorized equipment. I added a few gallons of fresh fuel for good measure.
Can anyone suggest something other than "the hook". I can't bear to let others see the car being towed to the service center.
Thanks
Itchy to hit the road in Toronto......

.

This might be a shot in the dark but do you have a factory alarm? did you disconnect the battery? might the alarm somehow be doing its thing IE not letting the engine run?
If you have an alarm try setting from inside the car and starting the engine it shouldnt start then with your spare key in the alarm cyl shut it off from inside the car and then try to start the car... let me know..... the fuel filter is also a good place to look..... and also pull the plugs and see if they are wet looking , if so replace them and try to start the car......let me know.....Stan

[drew1]

Stan,

Where is the factory alarm control on early 944?

drew1

[mike944]

I had mine do the same thing after i changed the timing belts. I forgot to plug in the air flow sensor. But mine only ran for less than 1 sec. Maybe the connections are dirty, or the MAF got water in it and corroded. There are ways of testing it if you have a voltmeter and a little bit of electrical knowledge.

Also, a vacuum leak between the MAF and the throttle body causes a whole host of problems. Even though it's not quite as bad as a direct-into-the-mainfold vacuum leak, Making sure ALL the air that goes into the engine flows through the MAF is much more critical than i ever thought it was.

Mike

[Mike_T]

Oops. That should read 20 mm Hg vacuum.
Thanks for the ideas
I'll give the factory alarm a shot. is there a control box/relay for this thing?
The plugs were dry the last time I checked but let me check again.
The fuel filter is new - just installed.
The car ran fine when I put it to bed and the Mass Airflow Sensor checks out okay, voltage and resistance wise.
The fuel flow is sufficient but I haven't checked pressure. If I crimp the return line, which should raise fuel pressure,the symptoms are exactly the same.
Note to Raul. I changed my clutch last year
and it went smoothly. You may have caused some damage to the reference mark transmitter. Is the flywheel correctly re-installed?

Would like to race it......but I'd have to push it.

[Mrmerlin]

Originally posted by drew1:
Stan,

Where is the factory alarm control on early 944?

drew1

Hi Drew i am not shure about where the box is but on the 86 951 it is in the floor panel with the DME box it is a smaller box Black in color it should say alarm on it otherwise trace the hood switch contact wires to see where they go..... otherwise the only way to control the alarm is from the key switch... as a side note you can get to the back of this switch by removing the drivers side inner grill in the door jam and reaching up to it.. be aware that the speaker wires are also wound with the alarm wires so if you pull on it hard enough you will disconnect your L R speaker........Anyway all of this diagnosis is predicated on the fact that all the fuel injection connections are correct and that the plugs and leads to each connector are tight and have a lil bit of dielectric grease on them also all the vacuum lines are hooked correctly and the intake hoses are on and no cracks in the intake boot.......if she was a runnin when you put her to bed she should run when you wake her up.....of course might the timing belt be fouled up?

[asidrave]

Hi Mike. i never removed the flywheel and the refrence stud in the flywheel was not tampered with. stll confused as why the car wont start

[drew1]

Thanks Stan & Shaun,

drew1

[Mike_T]

Well I put in a new set of Bosch Plus 4's as the old plugs were a bit wet. Same symptoms.
I tried to start it with the alarm on and the engine only turned over but would not catch.
Thanks for all of the suggestions. Unfortunately nothing has worked.
Will let you all know when I get her going again.
thanks again.

[hawes99]

Mike,

I put a new clutch in last year and when finished I had the same problem. When I would start the car it would run for about 6 seconds and rev up to about 3000 rpm and then it would die as if it where not getting any gas. The first thing I did was change the fuel filter as it was dirty. This did not help. Then I put on a used fuel pump that was tested and running and this did not help. I did the fuel pump becasue I took it to a shop by my house and they spent two hours diagnosing it and thats what they told me was wrong.(I got my money back). So I finally gave in and had it towed to a Porsche shop where they hooked it up to their computer. They said it was the DME. Somehow during the clutch installation the DME got fried and was not doing it's job. I was able to pick up a used one for like $300 and now it runs just fine. I don't know if this will help you but it was the solution for me.

Nate

[Mike_T]

Thanks for all of the suggestions. Nothing seesm to work.
I've now checked everything including pump pressure, volume etc etc. I've even changed the gas for fresh stuff.
It has to be the DME. Does anyone know of somebody that offers a repair or exchange service?

[drew1]

Mike,

Try George Beuslink, 944 Ecology, in NY, USA. He'll test yours if he has car available, and sell you a working one right. I think 944 Ecology has a Web Site, his phone is 845/658-9593 according his Panarama add. Tell him you want yours back if it tests bad because he sells to a rebuilder.

He is a good guy, has great knowledge, and will be glad to shoot the bull about your problem.

Tell him Andrew Love said Hello.

drew1

[Martin Taylor]

try unpluggin one injector and see if it starts, fuel pressure could be too high due to a failed regulator.

[Lawrence Coppari]

Once I left off the connection of the aluminum pipe that connects the turbo to the intercooler. Engine would run for about 2 seconds, stumble and quit.

[Tom M'Guin]

Mike,

Put a volt meter on the 12v power pins (pin 18 and 35 on the 951, don't know for sure it's the same on yours) at the DME connector and see what happens when you crank the motor. Sounds to me like to are losing power to the DME after you crank the starter. This could be caused by a bad ignition switch, bad fuel pump, a bad ground, or dme relay, etc., etc., all of which may appear fine when probing them with the motor off. Hope that helps. There is a DME rebuilder advertiser in the back of excellence if you need it, but I'd either borrow a DME or put yours in another car before spending money on one.

[Mike_T]

Well, we put it on the flatbed this morning and took it to my regular mechanic.
I wanted to transport it under the cover of night but the hook cam at 8:10 AM. It was great as I got to talk to all of my neighbours; even the ones that I don't regularly see.
When we find the problem I'll post another message.

Cheers

One step closer to driving.

[Mike_T]

Well it was confirmed today by my garage that it was the DME. He also said that the new Porsche unit is CDN 2400 and a rebuilt is CDN1200 (divide by 1.55 for US$).

[asidrave]

mike, did you get it yet. i have a name of a place that deals in rebuilt dme's. they wanted $300+core for a rebuilt dme w/6 month warrenty. are you interested?