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HELP! -Running very rough, hard to get off line -'87 Auto

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Old 06-11-2014, 10:04 PM
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Bonton
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Default HELP! -Running very rough, hard to get off line -'87 Auto

HELP!

Was running fine, pulled off highway into parking lot and all of a sudden it went down on power, sputtering, low idle sounding like a subaru boxer.

Like half the cylinders are missing. Smelled fuel. I checked that all the wires were seated on both ends. Pulled the coil wire and re-seated at coil and gave it what I could on the dist (drivers side). Is there a coil wire on the passenger dist? Can't see under. Baffled I guess; not sure what to do.

Any help appreciated.

Best, Josh
Old 06-11-2014, 10:13 PM
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Bmw635
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Return hose fuel leak under the air filter? Smell of fuel and losing fuel pressure causing engine run rough?
Old 06-11-2014, 10:27 PM
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outbackgeorgia
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You can chase a lot of things-and get nowhere fast. IF everything else is ok (ignition, MAF,CPS and connector, both coils/plug wires, fuel,etc.) Swap your LH computer. There is a hybrid circuit inside that will fail, question is when. I chased this exact symptom for a long time but a rebuilt LH cured this very annoying issue.
Dave
Old 06-11-2014, 10:42 PM
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Hilton
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Here's the things I'd bother to try while waiting for a tow-truck

After its cooled for a minute, does it run ok for 30-60s upon restart, and then get worse? If so, O2 sensor or possibly LH is the culprit.

If you turn the key to the "on" position, can you hear the injectors clicking? If yes, then the LH has failed.

Another simple check is unplug and reseat the two coil wires (with the engine off!) at both ends.

Pull and swap the relays for the EZ-K, LH and Fuel Pump - all use standard relays (e.g. horn relay fits all those positions - use it in each socket to see if any of those 3 are bad).

Try unplugging the MAF (can be done with only the airbox removed - i.e. 2 10mm nuts) and see if it runs the same or better. If no change, its possibly the MAF or the harness inside the connector.
Old 06-12-2014, 12:02 AM
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Bonton
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OK relays worth checking. Last year I cleaned all under-hood grounds. Have replaced O2 sensor and installed rebuilt MAF.
Old 06-12-2014, 12:43 AM
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MainePorsche
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Originally Posted by Bonton
HELP!

Was running fine, pulled off highway into parking lot and all of a sudden it went down on power, sputtering, low idle sounding like a subaru boxer.

Like half the cylinders are missing. Smelled fuel. I checked that all the wires were seated on both ends. Pulled the coil wire and re-seated at coil and gave it what I could on the dist (drivers side). Is there a coil wire on the passenger dist? Can't see under. Baffled I guess; not sure what to do.

Any help appreciated.

Best, Josh
Josh,
My humble opinion - if you smell fuel on your 928 you must track this animal first.
Expose, and inspect, every fuel line from the pump to the front of the engine. Jump relay to pressure up if needed without engaging the ignition. Have more than yourself with eyes and lights on the lines. Once you've excluded a line violation then move on to the electrics.
My humble opinion.
Old 06-12-2014, 01:19 AM
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Mrmerlin
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FWIW if the engine cuts out and feels like its only running on 4,
then you would be wise to look at the cats,
if they are glowing red ,
then shut off the car and make sure its parked outside away from any buildings.

This can cause the car to catch fire.
it sounds like you have a failed coil wire dont let the coil wires touch any metal along their run
Old 06-12-2014, 09:25 AM
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Bonton
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Thanks guys, I've got good info to go on. I also replaced all fuel lines last year and installed a Y pipe so no old fuel lines or cats. will mess with her this morning and see what I can find. Thanks again for the help.

Josh
Old 06-12-2014, 10:35 AM
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Wisconsin Joe
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You say you are "smelling fuel."

Where? Under the hood or out of the exhaust?

It makes a big difference.
Old 06-12-2014, 11:24 AM
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MainePorsche
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Originally Posted by Wisconsin Joe
You say you are "smelling fuel."

Where? Under the hood or out of the exhaust?

It makes a big difference.
+1
Old 06-12-2014, 01:00 PM
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James Bailey
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With no cats on the car if one of the TWO ignition systems has an issue 1/2 of the fuel is being pumped into the exhaust so heavy fuel smell.....You have two coils, two secondary stages (on the hood latch panel in front of the radiator left side), two distributor caps and two rotors and two coil wires.....any of which can and will cause the engine to run on 4 cylinders...two on each bank.
Old 06-12-2014, 02:58 PM
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fraggle
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Coil, distributor or coil wire has failed. No not drive the car, likelihood of fire is very high.
Old 06-12-2014, 06:24 PM
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WallyP

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OP says "no cats", so not as much fire hazard...
Old 06-12-2014, 06:38 PM
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awilli6
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I agree with Mr Merlin. Same thing happened on my 87. I changed the coil wires & it ran better. I changed all wires and it ran like it did before the issues. I have two new coil to distributor wires you can get for $35 plus shipping



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