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Discussion Starter #1
I finally finished the engine rebuild on my '89 900 N/A :cheesy: , but now it will not start :cry: ...bummer.

When I dropped the engine back in originally it fired up on the first shot, it ran lousy but it fired right up. I had to pull it back out due to a leak at the timing chain case and now that the leak is taken care of, YES Anaerobic Sealer is definately the way to go on the timing cover (from my last post), it will not fire at all.

I have run the basic checks from the Bentley and all of the checks that are on the Townsend site, however I may have found the problem but need advice before I start purchasing things or possibly causing any harm to the system.

I am at the step to check the Power to the Air Mass Meter: "with the key on and the ECU connected, check that pin 2 of the air mass meter's connector has battery voltage"...mine does not show voltage. I also have no voltage to the AMM when running the test on the ECU: "Jump pin 5 to pin 21 with ECU unplugged then check for power at AMM."

I also find that I am not getting voltage at pin 25 with the key on. According to the Townsend tests I should have power at pins 18, 5, 11 and 25. Again, nothing at 25.

So does anyone out there know what could be causing this and what I need to replace? Any ideas at all will be greatly appreciated. Unfortunately I am a decent "shadetree mechanic" with mechanical but am lousy at diagnosing electrical issues :roll: .

Thank you.
 

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The first thing that comes to mind is that the '89 ECU was notorious for unreliability. Yours might just have chosen this moment to die (which would explain the crappy running when you fired the engine up the first time).

I'd throw in another LH 2.4 ECU ('88 to '90), and see if that helps:confused:
 

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Discussion Starter #3
Thanks ProfZ! :cheesy:

So I can use 88 - 90 for an ECU? That is great news since I heard that the 89 one was lousy.

Anyone have recommendations on which year ECU to get to use for my 89 900 N/A?
 

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Oyster said:
I also have no voltage to the AMM when running the test on the ECU: "Jump pin 5 to pin 21 with ECU unplugged then check for power at AMM."
In this case, the ECU is not in the picture at all since you've unplugged it. Have you voltage at pin 5 (on the connector block, not the ECU). If so and you have no voltage at the AMM with pins 21 and 5 jumped, there's a connection fault between ECU and AMM. If you have no voltage at pin 5 then there is a problem with supply to the ECU.

Best option for troubleshooting help here is to take a text copy of the townsend troubleshooting page http://townsendimports.com/Web/engine_folder/nostart24.htm
, fill in your results to the tests and post that here. Once we see your answers, we might be able to point you at an answer or the next test...

You did check all of the air intake hoses/connections and all of the vac lines. Did you remove and reconnect all of the electrical connectors at the engine? Did you check for fuel delivery? Did you damage your distributor electrical connectors so there's no spark or fuel?...
 

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Discussion Starter #5
I have done all the initial checks:

- I have fuel, fuel pump comes on just fine.
- I have spark at the coil and to each plug.
- all the vac lines have been replaced.
- all electrical connectors have been checked and re-attached.

I have run all the test that are listed on the Townsend site but am getting a failure on this one:

"Check the Power to the Air Mass Meter: "with the key on and the ECU connected, check that pin 2 of the air mass meter's connector has battery voltage"...mine does not show voltage." I don't get power when I jump the ECU harness while unplugged at Pins 5 and 21 either.

I also find that I am not getting voltage at pin 25 of the ECU harness with the key on. According to the Townsend tests I should have power at pins 18, 5, 11 and 25. I have power at 18, 5 and 11 but nothing at 25.

Thank you.
 

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Oyster said:
"Check the Power to the Air Mass Meter: "with the key on and the ECU connected, check that pin 2 of the air mass meter's connector has battery voltage"...mine does not show voltage." I don't get power when I jump the ECU harness while unplugged at Pins 5 and 21 either.
There was something about a relay being downstream of pin 21. Did you check that? Bentley says:
remove the system relay and check for voltage at terminals 30 and 86 of the relay socket. If faults are found, check the wiring between battery and the relay sockets
Did you find out where pin 25's 12V comes from? Is there a fuse gone upstream of that? According to the Bentley, pin 25 gets its voltage from the EZK control unit. This is in the engine compartment {possibly in the wing rather than the main bit}. Maybe you knocked its connector loose when working and might not have thought of that when refitting. That might also explain the poor running earlier.

Did you reconnect the two ground wires at the engine lifting lug on the head?

Odd, Bentley shows pin 5 {in all LH versions} to be connected to ground. Pin 11 doesn't appear at all...
 

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Discussion Starter #7
I will check the relay socket tonight after work and then go from there. That would be pretty sweet if the relay is dead and I just need to replace that. :cheesy:
 

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is it possible that you rotated the distributor or something?I dunno maybe im old tech but I dont see how the amm having anything to do with the engine not running.if my engine is running and I pull the plug on the amm the car runs abit crappy,but it fires....what about a vacuum leak?on my car if I pull a hose while it is running the car will just shut off...now if I can just remember what hose it was...
 

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Now ive been doing work on my engine, and i know that my distributer wont go on in the right spot (because i moved it around before i read the bentley manual about marking the spot.) Any way, how would i go about putting on in the correct orientation, obviously the car right now is at tdc, but i dont know how to do from there.

-Alex
 

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Can you look at any marks on the distributor from the clamp that might help you line things up?

Now sure what else to suggest. If it were me, I'd look at pictures of the 900 engine bay and try to judge from that where the distributor should be. Afterall, you only need to get it close enough to start the car. Then you can time it up properly using a lamp.

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Thats a good idea, ill see what i can do. Anyone have a good picture of the dizzy orientation inside their engine bay, perhaps with the cap off?

-Alex
 

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On the cap, there is the notch to align it properly. Clockwise from there the order of the leads is 1-2-4-3.
 

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Opps it has! And I realised that I answered the wrong question! He was asking about the dizzy not the cap. Are the ends of the dizzy shaft notch like an 8v such that it will fit in only one way? I can't recall.
 

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Discussion Starter #18
Ok, so back to the original post :cheesy:...it looks like it may appear to be the System Relay. All the tests in the Bentley seem to point to it, power to the relay sockets yet no power to pin 2 on the AMM and none on pin 25 of the ECU harness.

Hopefully this will do it for me and to be a good sport, I hope that DrSquirley gets his distributor figured out as well ;).
 

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GearHead said:
I dont see how the amm having anything to do with the engine not running.if my engine is running and I pull the plug on the amm the car runs abit crappy,but it fires....
Pulling the AMM's connector sets default mode in the ECU (as does pulling the O2 sensor's connector). This gives you limp-home capability--engine runs, but not well.

If your AMM quit so the engine wouldn't start, pulling the connector would enable it to start and would flag the AMM as defective.
 
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