Won't Start/ Intermitent Start (Fuel or Ignition Problem)

[Boneyard]

Greetings,

 

A couple weeks ago, I drove my car someplace, parked it, and when I tried to start it again, it wouldn't start. I checked to make sure it was getting spark, and everything was fine, so it seemed to me a fuel problem. I spent the next day troubleshooting, and the best I could come up with was that I got no voltage on the fuel pump fuse (12v everywhere else, 0v on fuel pump) in the on position. I unplugged the fuel line and turned the engine over, and no fuel came out, which I believe verified the fuel theory. I was going to have the fuel pump replaced, but had the shop diagnose it first. (I have no garage and broke bolts on the fuel pump mounting, otherwise I would've replaced it myself)

 

I had it towed to the dealership, and they said it started right up and that I had probably flooded it. I drove it for a week or two, but it did the same thing again two nights ago on my way to visit family. This time the tow truck driver verified that the fuel pump is not buzzing when I turn the key on.

 

I have checked the wiring diagram in my Haines Manual, and is seems that both the fuel pump and the coil are on the same fuse, so having 0v should keep me from getting spark. I will check again once the weather breaks, but my initial diagnosis seemed that there was a problem somewhere between the battery (probably ignition) and the fuse-box that was intermittently cutting out. It doesn't happen when it's running, only when I stop and start, which seems to imply the ignition switch itself. This would not explain the spark in the coil though.

 

I am unable to find a wiring diagram from the ignition to the fuse box, so I can' tell if maybe there is one wire or lead from the switch that feeds the fuel pump fuse, or if the ignition feeds a rail that all the fuses are supplied to.

 

I would appreciate any insight that any you might have. I would like to get at least another year out of this car until I can get something newer and give her a bit of a break.

 

Specs: 92 Loyale - 1.8L, 5 spd, Fuel injected.

 

PS While she was running, she had no problems with the snow here in Seattle. Yay Subarus!

[Caboobaroo]

First off since I noticed that this is your first post, welcome!

 

Second, I also noted that you have the SPFI EA82. If the dealer told you that you flooded it, I wouldn't take it there anymore since a FI car doesn't flood:-\

 

Now, since you said it still has spark (I'm guessing you checked it from the coil to the cap and to each plug), then yes, sounds like you have a fuel issue. First off, you need to check the fuel pressure to verify that you have correct pressure. If its weak (should be around 19psi at the filter IIRC), then I'd replace the filter and go from there. If it continues to have the same problem and fuel pressure is still low, replace the pump. Also, check the wiring on the pump itself to make sure its not faulty and causing a intermittent problem. If all that checks out, then check the FPR, located on the back side of the intake with a vacuum tester. If it holds vacuum, then its time to check the resistance of the fuel injector. Oh and the fuel pump will buzz on and off with the green diagnostic connectors connected under the hood but won't make any sounds unless its running. I learned that as well since I thought it was the culprit.

 

Now, I have to say I had a problem similar to yours after I got my RX running after I bought it (its not technically an RX but it did have the SPFI EA82 in it). I would drive it and it would sputter and die after about 30 minutes of running. Let it sit for 2 hours and fire right back up. If I drove it for about 15 minutes, shut it off and let it sit for 10 minutes, no start problem. Replaced the fuel pump since it was weak but continued to have the same problem. Went to check my fuel injector resistance at the connector on the intake and it popped apart. Somehow I had managed to partially disconnect it when I put the intake onto the new motor since the old motor was junk. Never disconnected it with my hands so it must have gotten pinched just right so when the plastic of the connector warmed up, it expanded and I lost contact inside of it.

[Boneyard]

Thanks. It's good to find other Subaru enthusiasts. This is my first one, but probably not my last.

 

The problem I am having, as I said, does not happen when I am running. It only seems to happen when I turn the car off and then try to start it again. Once it is running, it runs; it is only when I shut it off that it won't start back up again.

 

I will go ahead and check the fuel pressure, but I replaced the filter a few months back, so that shouldn't be the problem. I wouldn't be surprised if the pump is giving out, but I will need to get a hold of a tap and die. My car is so old that every time I try to remove something I either strip or break the bolt. I broke two of the bolts off trying to remove the fuel pump, so it is hanging on by only one bolt right now.

 

Just to make sure, my model has a fuel pump relay in it, right? Somewhere after the fuse and before the pump? Is that in the cabin or outside? I would prefer to spend a few dollars on one of those before dropping $300 on a new fuel pump.

 

BTW, the dealer was nice enough not to do the $600 repair I said it might need after it started right up, and didn't even do the full $150 diagnostic. So even if they aren't completely competent, at least they aren't trying to take all my money.

 

Thanks.

[Caboobaroo]

Fuel pump relay is inside the cabin, behind the glovebox I think but lemme grab my FSM and check...

 

Actually its under the steering wheel, one of the ones thats bolted to it IIRC that is hiding behind the ECU. It'll have a blue 4 wire connector on it.

[Boneyard]

Ok, so I went out and worked on it today. I think I checked the wrong fuse when I checked the voltage before. There are two fuses marked fuel; one marked fuel/ign coil (which I think is the right one, looking at the wiring diagram), and one marked fuel (height). I don't know what the second one is for, but it only has voltage at start, not on run.

 

The ignition switch appears to be fine, the coil/fuel fuse gets voltage at all times, and I hear a click when I turn the key on, but no buzz. I would guess the relay is working, although it could be another relay, unless the fuel relay is the only one. If that is the case, I would guess the fuel pump is going out. Unless the wiring to it is bad, which could be the case. It is pretty nasty out, and I am loathe to climb under my car in the mud and snow.

 

It does surprise me that it would only give out on restarts though, and not while driving. I am a little concerned about spending all that money for the part if it is a wiring issue. It seems though that as it stands, the wiring appears to be intact.

 

Thanks.

[Caboobaroo]

To check the pump, get under the hood right behind the driver side strut tower, plug the two green connectors together, get in and turn the key to "ON". If you hear the fuel pump cycle on and off, then you know its working. Also, check the fuel injector connection which is under the hood as well since I know about crappy weather and working on cars.

[Boneyard]

I didn't hear the fuel pump turn on. I got the tools to drill the bolts, and will do one last test on the connections tomorrow, but it looks like the pump is actually giving out. I am still trying to figure out why it would give out only while starting, and not while running though. Maybe it is seizing up or something, and the fact I got it to run for two more weeks was just dumb luck?

 

The green connectors (which I haven't seen mentioned in the Haynes manual other than a cursory appearance in the wiring diagram) basically hotwire the pump, right? So if that doesn't make it start, than can I assume either the wiring on the pump is bad, or the pump itself is probably bad?

 

Thanks.

[zyewdall]

Second, I also noted that you have the SPFI EA82. If the dealer told you that you flooded it, I wouldn't take it there anymore since a FI car doesn't flood:-\

 

Technically not true -- I've flooded my '89 wagon a few times by stalling it under full throttle. (pulling into a snow drift in too high a gear and not hitting the clutch in time type situation) Short of that, you are right, they don't really flood. If it does, you can clear it by keeping it floored while cranking it.

[Boneyard]

Replaced the fuel pump, and it started right up.

 

I think the problem came from:

 

1) I was testing the wrong fuse. There are two in the box that say fuel. One also says Ign Coil, and that is the one that (according to the wiring diagram) goes to the fuel pump. If I had been checking that from the start, I might have saved myself some time.

 

2) The fuel pump probably started seizing, freed itself, then froze again for good. I have had this problem with computer fans where they don't want to start when you put power on them , but once they are moving they are ok. I probably should've replaced the pump as soon as I had the first incident. I think the two weeks I got from it were just a fluke.

 

Thanks for your input. It really helped me a lot. Perhaps my process can help to see what others may be doing wrong when diagnosing a similar problem. Hopefully this really was the root cause, and it's not some crazy intermittent in the harness that will leave me stranded somewhere crazy next week. Like Redmond:eek:

 

Thanks,

 

J

[Gloyale]

Replaced the fuel pump, and it started right up.

 

I think the problem came from:

 

1) I was testing the wrong fuse. There are two in the box that say fuel. One also says Ign Coil, and that is the one that (according to the wiring diagram) goes to the fuel pump. If I had been checking that from the start, I might have saved myself some time.

 

2) The fuel pump probably started seizing, freed itself, then froze again for good. I have had this problem with computer fans where they don't want to start when you put power on them , but once they are moving they are ok. I probably should've replaced the pump as soon as I had the first incident. I think the two weeks I got from it were just a fluke.

 

Thanks for your input. It really helped me a lot. Perhaps my process can help to see what others may be doing wrong when diagnosing a similar problem. Hopefully this really was the root cause, and it's not some crazy intermittent in the harness that will leave me stranded somewhere crazy next week. Like Redmond:eek:

 

Thanks,

 

J

 

I do not want to rain on a parade. But I have a few questions? So the Ign Coil fuse, was it blown? Poor contact? If so that was probably the issue altoghther and your pump was OK. That is the second question I guess, did you test the pump? verify that it was siezed?

 

Hopefully you HAVE solved it.

 

however,

It's also somewhat possible that the Distributor could be failing after hot. No ignition pulse signal = no grounding of FP by the computer. If you truely have spark, this is not likely the issue.

 

A few other possible culprits could be the Fuel Pump relay, or the ECU itself. *search for threads about burnt transistor in the computer.

 

Also, a bad Coolant Temp Sensor (CTS) can cause trouble on restarts, not closely related to fuel pump function, but a common *parking lot stranding* type failure.

Might be handy items to pick up spares of.

Edited December 31, 2008 by Gloyale

[Boneyard]

Ign Coil fuse was fine. It worked perfectly.

 

My initial diagnosis was in the Fuel (Height) fuse, which I though went to the pump. It measured 0v when in the ON position, which led me to believe there was a break in the circuit between the battery and the fuse. It was only after reading the wiring diagram and looking at the fuse box more closely that I realized I had been looking at the wrong fuse altogether. The Ign Coil/Fuel fuse read 12V during ON and START.

 

I thought it might be the relay/ECU but everything else was working, and I heard a relay click when I turned the key on. I assumed that everything else was working and the pump was the problem. Since I am an electrical guy, I tend to think electrical problems, and I didn't want to fall into that trap.

 

If I get the issue in the future, I will probably replace the relay, and then the ECU. I did get some weird burnt electronic smell in my cab a while back before I replaced the alternator, and had some problems with my CD player not wanting to eject CDs (which miraculously fixed itself just recently), so maybe the ECU is fried. I don't even want to think about how much those cost. Or about how I am going to get the dash panels installed AGAIN.

[Cougar]

As you may possibly know by now, the fuel pump motor is grounded through the ECU and as Gloyale stated, if the ECU doesn't see ignition pulses the fuel pump is turned off. That should cause an error code if that happens. If I remember correctly, the fuel pump relay is controlled by power from the ignition relay so that relay can cause this trouble also. I tend to think this trouble is due to a faulty relay but hopefully you have fixed the trouble. If the trouble returns then I would suspect the one of the relays as the cause.

[Gloyale]

IF this happens again, No restart after drivng and warming up, I would seriously replace the Coolant temp sensor. or at least remove it and test it through its whole range. whack it a few time while you're testing, often the will read OK til you whack them and then jump all over.

 

I've seen a rash of this lately, maybe fromt eh cold weather, but even a CTS that "tests" good, can still have dead spots or fluctuations. The ECU has a really hard time figuuring out how much fuel to inject.

 

Also, fuel pump running/ not running stuff: The fuel pump doesn't need to run continually before starting. It only comes on to pressurize the system, then will stay off until the injectors need more pressure. So not hearing a contiuos operating pump is not out of the norm.

[hooziewhatsit]

Sounds like what my BILs 91 loyale was doing. The fuel pump would get 'stuck' wherever it stopped (sometimes), and wouldn't start pumping until it was bumped. After it started pumping it was fine.

 

I verified by connecting the green connectors and tapping on the pump, then having the pump start working. Replaced the pump and haven't had an issue since.

 

Hopefully you got it figured out.

 

-Dave