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Discussion Starter #1 (Edited)
Hello everybody! I'm stumped.

My daily driver quit on me at work the other day and i havent been able to get it going again. It is a 1994 convertible with 134k miles, spg APC box, Bosch red injectors, high flow pipe and air filter.

When i got off work the battery was totally dead. I had left the brights on all day unknowingly. I got a jump and and it fired right up and then immediately died. Then it would just crank and crank and dump fuel out of the exhaust manifold and turbo and not even fire. The plugs come out soaked in fuel.

I brought a charged battery -- but have since killed it trying to start it. I have checked for spark - it is good. It has a new rotor/dizzy cap, plug wires, plugs. Hall sensor connection is all intact.

If i unplug the injectors and crank it will start to run on the fuel it has already dumped into the head. Then it dies becasue ot runs out of fuel. When i pop the banjo off the end of the rail it is not pressurized. The FPR is not leaking -- I even swapped it for a good one. I replaced the fuel pump and confirmed it is getting 12 volts while cranking.

All vaccum lines and turbo pipes are attached and intact.

I have compression, spark, and fuel. What is going on? This all occured after I completely drained the battery. Could it be a bad check valve? Is there and anti-theft system doing something? Just a bad battery connection? I need some advice here, it is hard to buy groceries by bicycle!
 

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Discussion Starter #3
Try this:

The injectors are recieving 12 volts each and constantly while the ignition is turned on. It is a constant flow of fuel from them whenever the ignition is on and they are plugged in. I drained the oil today and it had at least a gallon of gas in it. Does this seem like an issue with the LH control unit or is the unit not recieving proper tach signal?
 

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Discussion Starter #4
The tach bounces when the ignition is turned on. At the test socket there is 12 volts on pin #5 with the ignition on. I have read to not turn the ignition on with the ecu unplugged and I cannot test the pins with the ecu plugged in becasuse it is hard plastic cover, not a rubber boot that can be peeled back to reveal the connections.
 

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Could the LH unit, could be the wiring harness. Ground is supplied by the control unit in time with the tach signal, so the only way you should have ground there is pulsed. Is there continuity between the negative terminal of the injector (NOT the blue/red wire) and a ground point on the body with the key off?
 

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Discussion Starter #6
Could the LH unit, could be the wiring harness. Ground is supplied by the control unit in time with the tach signal, so the only way you should have ground there is pulsed. Is there continuity between the negative terminal of the injector (NOT the blue/red wire) and a ground point on the body with the key off?
With the ignition off and testing for continuity at the injector, my multimeter beeps once quickly and reads about 55 ohms continuously.
 

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Discussion Starter #7
I can't help but wonder why this happened after the battery was drained completely. The car has an aftermarket stereo in it got reset which is something that has never happened before.
 

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That suggests there could be a wiring problem. I would inspect the fuel injection wiring harness carefully and thoroughly to be sure it's not damaged. I would probably also remove the connector from the fuel injection ECM and repeat that continuity test to isolate the issue down to wiring or the injector drivers. My money is on wiring, as I don't think I have ever seen a Bosch ECM fail in that way...
 

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Discussion Starter #9
That suggests there could be a wiring problem. I would inspect the fuel injection wiring harness carefully and thoroughly to be sure it's not damaged. I would probably also remove the connector from the fuel injection ECM and repeat that continuity test to isolate the issue down to wiring or the injector drivers. My money is on wiring, as I don't think I have ever seen a Bosch ECM fail in that way...
I read no continuity at pin #1 or pin #18. The wiring harness appears to all be intact. I used to have an 87 spg and there were cracked wires all over the place but i cant find one in this convertible. The only thing that is abnormal is the sound system and even that looks like it was done with some compentancy.
 

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Discussion Starter #10
Some more things I have noticed: with the ignition on, the APC solenoid clicks very quickly and quietly.
Also the ANTI LOCK light and brake fluid light both turn for about 3 seconds when i turn the ignition to on, then they turn off. The ABS pump turns on and runs for about 2 seconds everytime i turn the ignition to on and everytime i step on the brake pedal with the ignition on.
 

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Have you watched (using eyes) what the injectors spray when it's trying to start with everything hooked up?
Do they pulse equally or squirt like a fire hose?
 

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Discussion Starter #12
I have not not pulled them and turned the engine over with them out. I could pull them but I feel like it is unnecessary at this point. If i plug a spare injector in that I have it opens up. If the ignition is on and I plug them in I can hear them open and flow fuel constantly. I'm am working on borrowing a spare ecu from the local saab mechanic.
 

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Discussion Starter #14
New issue!!

The car ran great with the new ecu. I put the dash back together and deove ot to the gas station to fill the tank because it was low. The check engine light came on before i left but the car was running as good as ever it seemed. I made it to station and filled the tank completely and only made it a couple hundred yard from the gas station before it died. Only this time it would start and then immediately die.

I got it home and have learned that there is no power at the fuel pump fuse or at the pump itself. I jumped terminals 87 and 30 on the relay that is nearest to the engine above the ecu, which to my understanding is the fuel pump relay, and it made no difference. The plugs come out dry, it will crank and run for a second then die. I am resnting this car at the moment. Any more help is much appreciated.
 

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Discussion Starter #16
There is not supposed to be unless the engine is cranking.

They'll start and die if a piece of the intake piping blows/falls off.
Update: The car no longer runs at all. I have checked all the intake piping and vacuum lines several times -- its all intact and connected. With the car cranking, there is 12 volts at the fuse but no voltage at the pump. I checked for spark and it is orange and intermittent. The coil tested at about 10,000 ohms resistance, but I swapped an extra one in -- no difference. The hall sensor connection is intact, the rotor, cap, plugs, and wires are all basically new.

I am suspecting that the ICM to be bad. Will the fuel pump fail to kick on if this thing isn't functioning properly?
 

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Discussion Starter #18
So I finally got some more hands to help diagnose. My solo tests with a video camera turned out to be inaccurate. The pump is getting power while cranking. Spark is good. I even applied 12 volts straight to the pump while cranking and it made no difference. I swapped in another ICM and it made no difference. I swapped in a good air mass meter and that made no difference. I replaced the main system relay with another that I had laying around, you get the idea.

The first start of the day the car will fire right up and run for a few seconds before dying. Then it will just crank and act like it wants to start but just wont.

I had a similar issue in a porsche 944 a while ago and it turned out the anti theft system was killing the car.

To me it seems like a fuel delivery issue. I am going to replace the fuel filter next.
 
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