Project Loki - 1988 classic SAAB turbo

[Jordan]

They are the same, they are both "Fuel Injection" relays in my mind since they are the only two relays in the Fuel Injection wiring harness.

[Adrian Thompson]

Ok frustration level 10.

Bentley manual pages 240-10 onwards, Electrical checks.

System relay.
1.0 remove mass air and control unit connectors. Done
2.0 check ground at pin 11. Done. Good.
3.0 pin 21 on connector to ground, ignition on and check voltage at pin 9. Done. Good voltage 13V
3.0 check voltage at pin 2 on mass air. Done. FAIL. 0V
4.0 remove system relay. Check voltage at pin 30 and 86. Done. Good voltage
5.0 check continuity to pin 21, pin9 on Ecu. Pin 2 on mass air and pin 86 on fuel pump relay socket. All checked all good.
5.0 says if that's the case but no voltage to the mass air then it's the relays.

So I connect voltage to terminals 85 and 86 and it not only clicks, but I go from no continuity between 30 and 37 to having continuity between them.

WTF now?

[Jordan]

Forgive me if we already established this, but to recap, you have no fuel pressure right?

If you supply power to the fuel pump directly (or jump the relay) does the pump run, you should be able to hear it coming from trunk. If it does not run, just double check that you have power at the connector going to the pump

[Adrian Thompson]

Forgive me if we already established this, but to recap, you have no fuel pressure right?

If you supply power to the fuel pump directly (or jump the relay) does the pump run, you should be able to hear it coming from trunk. If it does not run, just double check that you have power at the connector going to the pump

I have a healthy spark. The fuel pump circuit hasn't worked since I got the car so I jump the relay block. I've now ascertained that the relay(s) are good, but it doesn’t work. The pump runs and I do have fuel pressure to the fuel rail when I jump the relay.

I have traced the wiring (as above) per the Bentley manual and it seems to pin out correctly.

What I don't have is voltage to the MAF plug when the relay is in the system

What does this indicate a dead ECU? Anything else to check before looking for another? Does anyone have a known good LH2.2 for an 88 turbo? If so how much with shipping to 48025 ZIP?

thanks

[DrewP]

With the key switched on, give ground to the pin at the ECU connector that is supposed to close the fuel pump relay. If it works, then it's your ECU. If it does not work, there is a problem in the circuit somewhere.

[Adrian Thompson]

Thanks, I'll check that tonight. If the ECU is dead I have a lead on a replacement.

[Geoff]

This sounds similar to a dead ECU I had on an '85, at least what I can remember from years ago...
Some idiot had put the wrong impedance injectors into the car which ended up frying something in the ECU.

[DrewP]

I had an '85 LH2.2 ECU that would fry the filament in AMM's at key-on. Went through like 4 AMM's until we figured out what the heck was happening and wondering why the car always drove so bad. I think there's a skull and crossbones still drawn on the case of that ECU somewhere in my stash.

[Adrian Thompson]

Good news I think. Everything connected except the ECU and the MAF plug. Power on, ground to pin 21 and the fuel injection relay and 'click' it triggers. Dead ECU it is then. Off to paypal for me.

[Adrian Thompson]

So, good news, an 86/87 LH2.2 ECU has just arrived in the mail from Jordan. I was about to rush out, plug it in and turn the key, but before I do that is there anything else I should check to make sure I don't damage another unit?

[Adrian Thompson]

No start, think I'm off to buy a gallon of gas and some matches

[Jordan]

Well it was worth a shot...

[Adrian Thompson]

Well I'll do some more checking this weekend then I throw up my hands. I've posted on GRM to see if anyone wants to come and help me next weekend in exchange for beer and Pizza. I don't think anyone on here is remotely close to SE Michigan are they?

[Geoff]

No start but do you have voltage to the AMM now? Do all other systems check out OK?
Might be time to replace the gas if you haven't.

I assume you've checked all the fuses...

[Adrian Thompson]

Can someone tell me exactly where the pressure switch 144 is mounted. Bentley says near the turbo, but I can't find it. Also if it's unplugged or broken will it affect starting? I assume not as I assume it's just for fueling under boost, but I want to check.

Thanks