MY83944

It has been a rough year for the 944. The car will start, idle, run at minimal throttle up to 2000RPM. When it hits 2000RPM, it just dies. If you give it more than minimal throttle, it dies.
I have tried another AFM, DME, removed the wires going to the TPS (I have a new one, thanks to someones suggestion, but the car had the same symtoms with the wire removed, so I might have wasted $70.00 there).
I am going to try the fuel filter this morning. Time is running out on this car. I took it in for a body restoration last August. $6500.00 plus about another grand is misc parts, the body looks great. Really nice. But the car quit running while in the shop, and I finally took it away from them in August of this year.
I have the car in a barn 3 hours from my home, so it is a hassle to keep running in and trying stuff to fix it. Needless to say, my 944 funds have been depleted. Car ran great with no problems when I took it in to the shop, which is now out of business . . . .
Anyway, they did set the alarm off, and only removed the siren. I do not have a key for that, and assume that if that was the problem, the car would not run at all.
If anyone has any constructive, real world experience in what would cause a 944 to start, idle fine, but die if 2000RPM is reached or anything more than 1/4 throttle is given, please email me directly.
Thanks in advance,
Steve

icat

My suggestions...

Look for a vacuum leak.
Change the fuel filter.

No shame in letting a 944 specialist look the car over either. Might save you alot of fustration and expense - especially with as much as you've already invested.

User 41221

Couple of questions... first, what year 944 are we dealing with? Second, can does it stumble and die, or just cut out completely? Lastly, in which direction from KC is the 3 hour trip?

I am guessing vacuum (best guess would be air intake boot) or fuel (fpr or filter not allowing enough gas to keep car running at higher rpms).

I am located in KC and would be willing to help out, let me know if you want some assistance.

Regards, ...Scott

User 41221

Um, or what Keith said... lol

I didn't read his post before I replied. Sorry to be redundant.

icat

You know, I couldn't think for the life of me what the "air intake boot" was called - so I just said vacuum leak. Glad you posted Scott!

Look for a tear in the boot - tough to spot, but a common failure point.

I like to suggest everyone modify their signature in their profile to include their car information. Lots of differences between the models - helps with the answers. <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

MY83944

Long day . . .
Replaced DME, AFM (loaners from the Cooper Cup Holder), checked TPS and the reference and speed sensors.
I better take a step back - We attached a volt meter to the coil - when the car "dies" - at about 1700 RPM, the voltage drops to about 3 volts. Everytime the car dies. So we kind of ruled out fuel (so that must be it . . . ).
We did not have any good testing criteria for the reference/speed sensors, but they had a minimal ohm reading on two of the terminals of the sensor wire connector. Both sensors also demonstrated a "pulse" when cranking the car over. Car would not run with either unplugged.
The we tried the alarm switch wires - the alarm was tripped when the guys were doing the body work. Their was a small black box in the front spoiler when I took the car in - it is now gone. I thought it was the siren for the alarm - may have been the alarm itself. Anyway, the "mechanic" said he removed it and all the wiring through the dash. I am wondering if their is another alarm "black box" somewhere that may be tripped. We tested the alarm switch wires, both free and then both conencted, and that did not good. Maybe not the alarm . . .
They one thing I forgot this trip was my factory manuals. The Haynes was not much help. I am leaning towards the reference/speed sensors (still for some reason) and the alarm. When my fuel pump went out, I had no spark, and with the volt meter telling us the voltage to the coil goes away, I still don't think it is fuel related . . . I dunno . . .
Any ideas, thoughts, miracles, curse removing prayers, encouragement or suggestions welcome.
Thank you,

MY83944

Oh - It is a early 1983 944. I don't know what happened to my screen name - it was my83944 . . I have been lurking this year ..
:-)

billybones

I have never done this to a P-car. But I have used this method before to determine if it is gas related or ignition. I spray a decent amount of starting fluid into the intake hose. infront of the filter. Wait 15 seconds or so. Then start it. if it runs good for a few seconds. I know it is a fuel delivery problem. If it stays the same I know it is spark side related.. I have no idea what this might do to a P-car. But that is what I would do to atleast narrow it down a bit.

triscadek

Since the only variable introduced to this deal since it ran OK is tripping the alarm, I lean towards it. I really can't see a boot tearing with the car not running or a sensor going bad with the car just sitting, unless the bodyshop people did some horse assed thing and won't admit to it. But it still smells like an alarm related deal.

MY83944

This Sunday morning, I checked the fuel volume ands replaced the fuel filter. Replacing the fuel filter by muself was fun, especially when the remaining gas from the filter poured all over me and my daughters flashlight, that was on.
Car still dies at a certain RPM. This morning, that decided to be 2200 RPM. Consistantly, when it hit 2200 RPM, "IT" shuts off.
Boy, does the car look good though.
I also check all the vacuum hoses again, my coupld year of AFM to throttle body hose, etc.
Any car this hard to diagnose is a POS.
I can't wait to get home to read my manuals and see what other fun I have ahead of me. Thinking Alarm or Speed/Reference Sensors, need test data. In those manuals I left at home 3 hours away . . .
Plates expire in November . . .
Time crunch . . .
Steve

triscadek

Ah! The feel of cold fuel running down your arm first thing in the morniing.

'rik

i would just like to add that when my speed reference sensors broke.
the mechanic said that they gave normal readings when he tested them.

he borrowed some from another 944 to diagnose.

SoCal Driver

Having the voltage drop at the coil means something is shorting out the coil to ground. This is either a bad DME, a bad tach, an alarm or bad wiring.

If the alarm system has been completely disconnected then it's the tach or DME. You may have to disconnect the tach by pulling the plug on it.

If the DME is doing this it's going to be difficult to check without swapping the DME out for one you know works. If you do this swap make sure the DME you get is for your year of car as post 85.5's are a bit different.

I suspect the alarm as some alarms will disable the car by sorting the tach wire to ground which is the same circuit that the DME uses to trigger the coil to fire.

Other components that can limit running RPMs would be fuel related. The regulator, dampener, fuel filter and fuel pump. The regulator and dampener are vacuum controlled. The small black vacuum tubing can come loose or even the rubber elbows and tees can crack. There are two points on the throttle body where the small tubing connects. These may be backwards -- connected to the wrong tubing circuits.

As to the speed and reference sensors; if the car can start and run till 2000 rpms the sensors have to be working. You are getting the required resistance and impulses from them. Still the speed sensor does tell the DME to keep the fuel pump running besides part of the data to determine the amount of time the injectors stay open. The rest comes from the two temp sensors, the AFS (Air Flow Sensor) and the Ox sensor if you have one.

Check the voltage at the injectors. Should be the same as the battery. If/when the car dies see if this voltage stays the same as the battery. If there is no voltage there with the key on then the DME relay has dropped out. If the voltage is greatly reduced then there is a bad ground between the engine, chassis and battery.

All in all I think this has something to do with the alarm. Either it's still connected or it has damaged something before it was disconnected.

triscadek

I recall a post where there was something about removing the alarm keylock and the car will not run without a resistor attached to the plug, I wonder if your problem could be in the alarm removal?

If I can find that post I'll bump it.

MY83944

First, I appologize for acting like a **** and even lower myself to saying . . . bad things about our 944. That was an insult to all 944's and I am sorry. Anyway, our 944 still is not running, but . . .
I called the mechanic who worked on the car. Only a true professional takes calls himself. He told me that they did not remove the black box (which I assume is the alarm brain) from behind the spolier. He relocatied it "in there somewhere". OK . . .
I then asked about the siren and the wiring they removed. He said they cut the wires going to the alarm siren, located near the battery in the cowl area. He said they did this because it would not turn off.
OK, then, I said to him, you don't think that might have something to do with why my car would not run properly?
Anyway - OHMMMMMMMM - Calming down . . . I have a feeling it may be my alarm. I do not have and never had a key.
I am going to have my brother in law (really cool dude) hook the siren/horn for the alarm back up. If it is still sounding, he will then try to remove the alarm lock cylinder and have a new key made for it. Should cost about $40.00 I think.
We are hoping this fixes this saga of our 944 and I can get to help others.
Thank all of you that help with the diagnostics, support and for not flaming me in my moments of dispare.
Steve
(Any ideas on bipassing the 83 alarm system welcome)