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aa8jz

88 gl dies, restarts, dies, etc.

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Drove my son's car to work. Died as coasted into my parking spot.

The car, not me. Good timing. Wasn't late. Left in pm and sputtered home.

Connected white read memory connector and read 11, 13, 14 and 34. 34 has been a long time buddy and has not caused any trbles that I am aware of. I believe these other codes refer to the crankshaft position sensor. Relaced distributor (houses this optical sensor) with a different (used) unit. Ran the same. Replaced ecu with another used- no change. Drove with this second ecu about 1 mile or less. Checked codes and did not flash 11, 13, or 14. I guess my question is does it take more then a short bit of driving to set these codes if indeed the input device is still in error? Btw, put a good oscilloscope on pins 19 ,20 and 21 of the ecu and found the 360 pulse per rev signal looking pretty good. The 4(?) ppr sig had an occasional burst of noise that seemed to correspond to the sube spitting at me. Connector / harness / ground issue?

Had to quite this evening. Down to abt 20 f. brr

tnx

rick in Mi.

93 loyale

90 legacy

88 gl

86 xt

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wow not your average parts swaper.but a scope man.

I probably dont need to tell you but the 360 signal is for timing control and the 4 is the actual triger. if you have crappy noise or whatever you see on that signal thats not cool. make sure plug wires and disty wires are not rubbing. did you check the power and groung to the disty?

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rallyruss

tnx for reply. I am an instrument tech by profession. some times my employer lends me a real good fluke scope with out knowing it.

have yet to investigate bundling of wiring. I have the feeling that the misshapen waveforms are what the ecu is really getting and am thinking of throwing a small capacitor on the ecu input wires to see if it can quite this thing down. I don't want to give in and have someone else repair this trble. The waveform does not dropout, just becomes very noisy.

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I'm down in Big Rapids, i think you may be close, i am currently immobile but by friday i should be on the road again, if you need help i got manuals and a buch of EA-82 SPFI parts if you need those too.

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Your fuel pump may be on the way out. You could try starting it and give it a shot of fluid as the motor starts to die. If it keeps it going then you are probably going to need a new fuel pump.

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Glenn

Tnx for the idea. I installed a tee at the fuel feed and had pressure gauge on the dash while driving around. Held pretty darned steady at 25 psi or so. That should scratch that issue.

 

Noah- Will keep your offer in mind. I have Mitchell on Demand but it leaves something to be desired. FSM would be delightful. How about a source?

 

agn tnx

rick

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Your welcome for the help.

 

Did the engine die while you had the pressure gauge hooked up? If not, then you still may have an intermitant pump. This happened on my 88 GL-10.

 

Another thing you may want to do is replace the fuel filters. I think there is two of them. This may be the real problem.

 

I have the full set of service manuals on the 88 if you need any info.

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I may be totally off base here, but I seem to recall something about having a timing belt slip causing position sensor codes to be thrown. Have you checked your valve timing?

-Louis-

'91 Loyale 4wd 5spd Wagon

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Glen- yes the car died while monitoring the fuel pressure. Pressure remained constant.

 

Louis- I have yet to check the cam timing. I believe though that if this timing was off it never would run well. In between failures it runs great.

 

Point 1- fuel pressure always there

2-monitored voltage to injector with o'scope while driving down road. Sputtering occurs in conjunction with missing injector pulses.

3-funk on the 4 pulses per rev crankshaft position encoder also jibe with the sputter- dying. 360 ppr sig looks good.

So- the ecu is funneling a bad input sig through the logic and causing the missing pulse string to the injector. Isn't this sort of how the whole thing plays? Man, sure wish I knew more about this stuff. Can't learn without struggling though.

I noticed while studying a Mitchell on demand schematic that this crankshaft timing signal is encased in a sheilded wire as it goes to the ecu. Have we seen breaks in this sheild? I hate ripping the blasted harness out.

tnx agn all

rick on east shores of lake michigan

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One more thing.

Rallyruss. I did not throughly check the grounding of the distributor wire. Missed doing it. Burned out from work I guess. That should be easy and has decent chance of being the culprit.

Will notify if and when resolved.

tnx

rick

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Rick, what are your thoughts on the shielded wire coming off the distributor? I also am having a non-start issue and the shielding on the distributor wires in not contiguous due to a needed splice.

 

 

It's good that you have such excellent tools to play with. Should make short work of your problem.

 

Regards,

 

Jay

 

jaykili(at)cox(dot)net

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Originally posted by aa8jz

Louis- I have yet to check the cam timing. I believe though that if this timing was off it never would run well. In between failures it runs great.

Ahh, didn't register in my mind it was running ok between failures. I thought it was still just sputtering along.

That would almost surely rule out timing belt issues. I think the 4ppr issue is definitely a clue IMHO. I wouldn't rule out a coil issue, also. Otherwise I would be willing to bet a wiring connection problem.

Good Luck and keep us posted-you've got my curiosity up.

-Louis-

'91 Loyale 4wd 5spd Wagon

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Well it seems you have ruled out the fuel system Rick.

 

If the distorted pulses you are seeing are looking ok while it is running ok and then noising up while it is misbehaving then it sounds to me that the CPS sensor is intermitant. I think this is photo electric type sensor. If the ground to it is ok then that may be what you need to change out. I think some of these engines have a transistor mounted on the side of the distributor if I remember right and it could be that also. They can cause this kind of problem I believe.

 

Glen - In Anchorage by the Cook Inlet.

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Glen

Have swapped the cps to no avail. It was an old used unit but symptoms were identicle.

I need to go over the ground and plus supply with fine tooth comb. Heck, I don't need it for my hairs any more. Either of them.

Although, if ground or plus supply issue it sure seems would show up on the 360 ppr sig. Too much theory after a long day. gn

 

rick

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After reading the pervious posts again I see you have replaced the vital parts already. My suspicion now is you may have intermitant power going to the ignition system. There is a ignition relay that has two sets of contacts that close when the key is turned on. One set is fed power through fuse #5 and the other set is fed from one of the four fusible links (a green one). These links are in a small plastic box that is mounted to the coolant overflow bottle. The lid will open by pulling up on it I think. Sometimes the contacts for the links can become loose over time and make an intermitant connection. Check those connections, if you see signs of burning you will know what to do.

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well, in my newest runing efi vehicle, yesterday, when the fuel pump conections got loose, the tach started doin funny stuff, sputtering a little, all the same stuff, thought it would die. and it does the same thing if the wires on the coil are loose. sounds like a loose connection or broken/half broken wire. good luck

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Thanks for all info and suggestions.

Did nothing this morning except drive to work and back. -16 miles

Ran fine. For now. Have decided to wire from crankshaft position sensor direct to ecu connnector with brand new shileded wiring.

Will ground shield on ecu end only. Float the other end of shield to eliminate gnd loop noise. Should be easier then looking for funky old wiring.

Will update.

rick

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Just an update.

Darned car is still running fine. Didn't find a culprit. Maybe removing, reconnecting, the crank angle position sensor quite a few times has temporarliy resolved the trble.

Also checked the fusable links and all appears ok.

If and when reoocurs, will completely rewire the sensor to ecu with new fully sheilded cable.

tnx all

rick

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