Yes it does which is why it might be a good idea to kluge something up to measure the pressure through the test port.

First description of the problem

If it didn't start at all the procedure below would be a good test. In 60 seconds of running the starting fluid will have completely dissapated in the intake.

good points, Rick. Sometimes I'm guilty of skipping over portions of a thread before I jump in. :(

I still believe it's gonna be a fuel pump issue. But it's also possible that it's a fuel filter or fuel regulator as well. I would quickly check these before diagnosing the fuel pump.

First let me say that I appreciate all your help.

Now let me clarify the situation with some updates

The car did fire up and ran like a champ for about a minute after I did the install of both flywheel sensors. Unfortunately I could never get it to start again. No hint at starting at all after that tease.

At that point I decided to replace the head temp sensor because it was the one wire type. That effort produced no results. I thought I may have disturbed it enough while I was installing the other two sensors, that I should try to eliminate it as a variable.

This made me wonder if I even have spark anymore.

To add one more variable to the equation. I swapped out the fuel filter which I don't think has ever been changed out since I owned the car. I don't think that was an issue at all because fuel flowed freely through it once I got it out.

I plan to crank it for a little while with the starter fluid to see if I get spark and to see if the fuel pump fills the filter up with fuel. I will let you know what I find.

I don't now where the test port is or what procedure to use to see if I am getting fuel pressure.

Thanks again,

Matt

OK, update:

I tried to get the car started using starter fluid. It would not start.

Another thing I noticed: After a start attempt the fuel pumped filled up the new fuel filter with fuel. This may not be an indication that the pump is building adequate pressure, but at least I know that the starting sequence is powering up the fuel pump, which I believe effectively rules out the new DME Relay. Am I wrong on that?

Where do I go next? Spark / coil testing or elsewhere?

The car did fire up and ran like a champ for about a minute after I did the install of both flywheel sensors. Unfortunately I could never get it to start again. No hint at starting at all after that tease.


You might want to check the clarence of the sensors again first, check for spark @ plugs second. You might want to bump starting it by pushing down the street and letting out the clutch with key in the on position. Spark and fuel it should fire-up.

Found this on the 944 site/ could you have the sensors pluged in the wrong conectors up-top?


Wanted to give an update about the car that almost got parted out! Well found a combo of problems, first the AFM was no good, had to get another, that was one of the big issues, then the second issuewas that I had bad ref and speed sensort. But here is where I messed up. THey guy before me had the harness destroyed! I had to hard wire the connectors into the harness. Each connector has 3 pins, black wire, yellow wire and the third is for the ground around the cables. I did not know the correct way to hook the wires up, due to it not working 100% before, so I hooked them up color to color. Well the Forward sensor, I think is the speed? Well that set of wires is crossed! I took the chance, switched them out, and works fine now, except the starter is going out! Cant win for loosing! Mike
__________________
I Love the Smell of Jet Fuel in the Morning!
86 Silver Porsche 944 N/A - Alpine CDA-9857
p?

Grabbed this off a different thread:



Have they checked the flywheel speed and reference sensors? They will also cause this type of problem. Gaps on both should be .8mm. The key for the sensors is the voltage generated at cranking:

1. reference - > 80-100 millivolts A.C.
2. speed - > 1.00 volts A.C.
__________________
'86 Carrera w/mods
'02 BMW 325i
2009 Ducati Monster 696

I was extra careful not to mix up the speed and reference sensors when I installed them (one at a time) as I knew that they were the same part used for two purposes, so I don't think they are swapped.

I do believe it could be the gap. I had to remove the bracket because one of the old sensors was frozen into it's socket. I pretty much reinstalled it and crossed my fingers that the gap would be right.

When it started for 30 seconds after the sensor install, I thought to myself the gap must be OK, but maybe not.

Later I read a post with a technique of using the old sensor with a superglued 0.8mm washer to achieve the proper gap. I should probably check re-gap before going any further.

Thanks,

Matt

Always easier the second time around..Was the engine running before you change out the sensors?
All the best,
Bob

nope, not running before I changed out the sensors.

OK, I used the "glue a washer to the end of the old sensor" trick to get a proper gap of 0.8mm for the speed sensor.

No change in how the car reacts. Does not show any sign of starting when cranking. I noticed the tach does not move, but I don't know if it really should before starts.

I am starting to get frustrated. :mad: I have to get it running before the snow flies so I can get it into storage for the winter.

Let me summarize some key things that I know so far.

* The fuel pump seems to be coming on during cranking as it filled up the new filter I installed.
* About a week ago, after installing the speed and ref sensors, the car started and ran for about 30-60 seconds like a champ, then quit like I took the key out of the ignition.
* The use of starting fluid today did not make the engine show any signs of starting on cranking.

All of this began when I changed out the battery this summer. The car died before I even made it out of the parking lot of where I got the battery. Back then I checked the terminals and all seemed to be hooked up properly. So I wrote it off to coincidence.

I had it towed to the shop where they swapped out the DME Relay. This seemed to fix the issue. When I picked it up, I took it to work where it wouldn't start. Rapped on the DME Relay, it started and then I drove it for about 10 miles without incident. When I got it home I shut it off in the street but had a hard time starting it. Rapped on the relay, it started but died halfway up the driveway.

The car stat for a few months due to a surgery and busy life. Now I am trying to get it started.

Interventions thus far include...
*New DME Relay again, (getting two clicks from it on start up)
*New Speed Sensor
*New Reference Sensor
*New Head Temp Sensor

What should I try next? :confused: I haven't completely ruled out a fuel delivery issues, but I am now leaning toward an electrical issue.

[QUOTE=cygtoad;4986897]

*New DME Relay again, (getting two clicks from it on start up)
*New Speed Sensor
*New Reference Sensor
*New Head Temp Sensor

I think the new DME relays are solid state now (no clicking).

Is the second one a new DME relay?

Check for spark at a plug of two.

I believe it to be that the DME relay has two functions one to activate fuel and the other to power DME box.

How are the wires that the DME relay plugs into? DME relay is suspect; could they have put a used part in there and a fully charged battery faulted that one too?

There is a major plug/engine harness connection thats behind the air intake, unplug and plug back together. It is laying down on the shroud in the middle.

how many times have you swapped out the DME relay? Are you absolutely sure your current relay is new, or at least good?

If so, it may be possible that your DME itself may have a bad solder joint somewhere, as earlier suggested. You'll need to remove the driver's seat and pull the DME. Remove the cover, and with a magnifying glass, inspect each joint. This does not happen often, but seems to be happening more frequently...now that our cars are 20+ years old now. Go ahead and do a search on this, there is a wealth of info about this.

Maybe there is another Pelican near you that will offer to help with a temporary switch out of your existing DME. It's very simple and fast.

I feel for you, brother. Please keep us posted on this.

Have you checked for spark? If you haven't, stop guessing and check. That makes a big difference. Also, sometimes even the best backyard mechanic needs to say "uncle", call a tow-truck, and take it to a pro that knows air-cooled Porsche to figure it out.

+1 on this prudent advice...(you may have reached a point of diminishing returns)


The DME itself (injector stage) and ignition system fault (e.g. coil) is not beyond consideration of failure...

I will check for spark and may even pull the DME unit to look for bad solder joints.

However I am on a time-line and need to get it fixed soon. I just wanted to avoid a huge bill from the mechanic, but it is probably true they could fix it faster. It is not like I have an oscilloscope lying around for further sensor testing.