PROBLEM: car fires but quickly sputters out, or I can rev it up a bit roughly but within a minute it quits anyway. Absolutely will not idle.

PRIOR SYMPTOMS:

In the morning it was having a bit of trouble staying started, the last week or so, but once it got started it was fine, except for a bit of hesitation on acceleration and lower than normal power going up hills.

The fuel pump relay is fine but I replaced it anyway. Started fuel pump with jumper and started car, same thing.

I recorded my main fuel pump on startup. I cannot hear it priming in position II. But I never could as long as I've owned it. Like I said, the fuel pump does turn on when you bypass the relay. But it doesn't run any better.

Any ideas what I should try next? Replace fuel pumps? Replace fuel pressure regulator? I don't know how to test it any further so I'm kind of at that "try it and see" point.

Also, does jumping the fuel pressure regulator plug turn on both fuel pumps or just the main one?

Thanks.

 

Your car is an '88 which has the LH 2.2 version of the electronic fuel injection. Only the later versions (LH 2.4 and later) prime when the key is turned to the II position so lack of priming is normal. Have you tried disconnecting the AMM and then starting/running the engine? If it runs without the AMM connected then it is most likely the culprit. It's doubtful that is the problem but check it anyway.

Check out this site for diagnosing the fuel pumps:

In the Tank - 240 Volvo Tank Pump and Sender

For the fuel pressure regulator, pull the vacuum line from it. If gas comes out then it is shot and needs to be replaced. Otherwise you need to fuel pressure gauge to further diagnose.

 

OK so I disconnected the AMM, first thing I noticed is gasoline pooled in between the ridges. But maybe this was from jumping the fuel pump relay? Anyway I tried to start it and it still won't stay running but now it making a really bad sound, like tin cans dropped on the ground. I'm getting scared to keep trying stuff. Any ideas?

also i tested the fuel pressure regulator yesterday, seems fine.

Thanks for your help, very helpful to know that about the ignition not priming..

 

Nevermind on the new sound of tin cans banging. The tailpipe was hiting against a pipe I put back there trying to listen to the lift punp in the tank. Oops. It starts with starting fluid, revs then dies. Someone in a video said this means it's the fuel pump. Someone wlse said if them fuel pump turns on with a jump in the relay socket then its a good pump, don't change it. But google says a pump can be weak/damaged and still working. I feel like changing the pump, maybe the lift pump too shouldn't hurt to try it. Can't even get a call back from a volvo mechanic, last one I talked to said most people won't work on these anymore because they don't have OBD.

 

Have you checked the pumps as described in the link I sent you?

Your last post states that it starts with starting fluid but your original post says it starts but does not run long and will not idle. Do you have to use starting fluid to get it running?

Using the "parts cannon" approach will most likely cost you more money. The link I posted above shows how to diagnose the in-tank pump. To test the main pump you really need to use a fuel pressure gauge. Many auto-parts stores will loan you the gauge (Autozone, Oreilly's).

 

So I changed the fuel filter and bench tested the in-line fuel pump. It seemed to work fine so I put it back on with the filter. Still no start. I also listened to the tank pump with a tube while the pumps were turned on by fuse panel bridge. Also humming. i was confused so I hired a mechanic friend to help me diagnose it. We couldn't do a fuel pressure test but he sprayed starter fluid into the throttle body and it started and died. So he had me crank it again and this time he sprayed it in and kept spraying it and it kept running as long as he sprayed it, for like a minute! Then as soon as he let off it died again. So he says it's for certain the fuel pumps.

I bought a delphi.pump that's supposed to fit, but requires cutting the wires and changing the connectors. I'm not really fond of this idea. Might just toss it and order a bosch since I have to wait a week for the new lift pump anyway.

Should I replace the entire fuel sending unit or just the lift pump? I've been humbled by this experience.

​​​​​Is there anything else I should do? My friend is a pro but not a volvo mechanic. He works at a BMW/VW/Audi shop.

Let me know what you guys think. Thanks I appreciate your input.

 

So, does it ever run without using the starting fluid? Your first post implies that it starts and runs shortly (without starter fluid) and then dies and won't idle. If it doesn't start at all without using the starting fluid then I would check to make sure the injectors are firing. You can use a "noid" light to check if the injectors are firing while cranking the engine over.

 

At first I could get it to run breifly revving it up and down, on every few attempts to start it. But then eventually it wouldn't do that. Then I bridged 4 and 6 on the fuse panel and force started the fuel pumps and it did it again. Then with starting fluid I was able to do that again. The only time it's ever idled is when he sprayed starting fluid directly into the throttle body continuously. You think this could be indicative of bad injectors? It was running fine the day before it happened, except for a noticeable loss of power on hills, and for a long time it was hesitating when going from idle to acceleration.

I'll look into checking the injectors. Hopefully a noid light isn't expensive. Thanks.

 

Injectors rarely go bad. Check if you are getting pulses to the injectors first. You can borrow a noid light at your local AutoZone. If you are getting pulses at the injectors AND you have fuel fuel pressure at the fuel rail and it still won't start then I would consider replacing the injectors.

 

Okay so I replaced the in-tank pump. Bench tested the old one and it seems fine, though the sock was deteriorated a bit. Car still won't start. I've verified the relay is working and that the pump is getting power, (though only 10.8v when the battery is at 12v.)
​​​​​Since the 1988 doesn't prime, do I need to do something to get fuel back in the line? I also replaced the fuel filter and bench tested the original in-line pump which emptied it. I did force start the fuel pumps again at the relay which I would assume would send fuel into the system. But maybe there's something else I'm supposed to do. Either that or there's some other mystery problem. The engine is not getting fuel and I can't understand why. Could it be a stuck check valve?

Appreciate your input.

 

I would disconnect the fuel line at the fuel rail, put the end of the line into a container and crank the engine to see what kind of fuel flow you are getting from the pumps to the fuel rail. Also, how is the fuel pressure regulator on the front of the fuel rail? If the hose coming from the fuel pressure regulator has fuel in it when it is disconnected, the regulator is bad.

 

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Did all that. Finally figured out it is a bad MAF sensor. Someone told me at the beginning to disconnect it and try to start. I misunderstood and disconnected it from the air intake without disconnecting the electrical connection. Big oops because I hired a mechanic to diagnose and he told me one or both fuel pumps were bad, so I spent the next two weeks replacing/rebuilding both fuel pump systems for nothing. About $400 in expense too.