Hello,
I have posted to this awesome forum and have had much appreciated advice. Since my last post I have done several things that needed to be done but have yet resolved my issue.
'92 Volvo 940GL no start. So far I have replaced the single in tank fuel pump, bad gas and fuel filter. I replaced a bad coil and cap/rotor.
I know the alternator is bad but will wait until it runs before putting $170 into that.
I have been able to get it to start and run with starting fluid; as long as I keep my foot on the pedal and keep rpm above 1500. So it is getting fuel now and spark.
Maybe Volvos werent meant for me as my last one several years ago as I recall was a curse as well...
I would greatfully appreciate any advice from this very knowledgeable group.

Thanks!

 

you say the alternator is bad, but assume battery is good for at least 12volts.
what happens if you unplug the MAF and then start the engine? symptom remains?

 

I think the first step would be to determine whether your car has the Bosch LH fuel injection vs. the Rex Regina system. Diagnose from there. The Bosch system has the cylindrical coil vs. a square coil on the Regina system. Once that is determined you can further diagnose. Only the Bosch system has the MAF while the Regina system has a MAP sensor.

 

Yes, it has the Regina fuel/ignition system. Im not familiar with Volvos much, however a guy helping me with the car left the cover to the air filter off, could that be the problem, even if its a MAP?

 

ok now 1st thing i would do is check fuel pressure.

 

Unfortunately I am unfamiliar with the Regina system but I don't believe unplugging the MAP sensor is a way to diagnose a no-start condition. Follow Silvermine's advice and check the fuel pressure.

 

Sounds like you are not getting fuel. If you spray in starter fluid and it starts but runs for a few seconds then you are just burning up the starter fluid. If you replaced the fuel pump and it is pumping then the fuel injectors are not functioning. So I would focus on the fuel pressure regulator as well as the electronics that fire the injectors.

 

Thanks for replying. I dont believe its the fuel pressure. First i checked the fow rate awhile back plus itl run all day as long as i keep it above 1500..
Im getting some new parts today, coil/cap rotor, (definately bad) i left the cover from the air intake off of it the last time I tried it, im wondering if this is causing a vacuum leak?

Thanks for the advice!

 

air leaks only matter downstream from the MAF or MAP.

 

Thank you Pierce, it seems pretty much every thing I have gone through needed replacing..fuel pump/filter, coil, cap and rotor, alternator. It has so far come back to the RSS. Im not getting voltage to the ECU all. Im thinking this is my final problem.) Ill let you know.

 

Is their any advice on testing the Radio Suppression relay?...Thank you.

 

I would have thought you had replaced this as one of the earlier issues. They are cheap and should be replaced every 1-2 years. Same with the FP relay.

 

I actually started their first by checking it had power to the rss relay but got distracted with everytging else. Doesnt seem to be getting power to the ecu.

 

Info here. Dave's Volvo Page - Volvo Relays

 

the RSS powers the injectors, its turned on by the ECU but doesn't power the ECU (except on some 94/95 940s where they replaced the old dual fuel pump relay with a single fuel pump relay, and moved the main ECU power out to the RSS... you can tell you have one of these cars if your fuel pump relay isn't where it traditionally was in the main panel behind the ashtray).

 

Thanks, is their a way to check the RSR as well as to see if power is getting to the ECU?

 

I meant to say RSR up there. not even sure what the RSS is ?

here's the wiring diagram for the fuel injection on a LH2.4 740/940


464 is the RSR, while 135 is the main fuel and fuel pump relay...

 

oops, you have regina, so that diagram is wrong, I don't have the regina diagram handy.

 

Thanks for the input. Ill let post how it goes!

 

Well I replaced the RSR, Cap and Rotor, new coil, new fuel pump and filter. I checked the compression 175/170/160/160.
The fuel pump relay is working as I can hear the pump going.
I guess im down to the MAP, Idle air valve.
I checked the resistance on the Crank position sensor, its a little off..165 should be 200 min according to Chiltons. I would guess it should at least start.
Im definately having a time with this thing...that said could it be a timing thing? When I put the rotor on I noticed that it had some play and maybe the timing is off.
Darn thing just doesnt seem like its firing.