2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

help I have a strange spark problem

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Old Nov 29, 2001 | 08:02 PM
  #1  
rx-lost 2nd gen's Avatar
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From: tx
Exclamation help I have a strange spark problem

My car started running realy rotten. It was jumping the idle up and down acting alot like a spark plug wire was ground out. I towed it home . My problem now is that I have no spark from any of the coils. The first thing I did was test the resistance on my crank sensor then my coils everything tests right . Another strange thing is when my egi comp fuse is pulled and the key is on the electric fan comes on I have no clue and I don't want the dealer to chaege me 1200.00 dollars and not fix it. Any way thank's for reading
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Old Nov 30, 2001 | 01:31 AM
  #2  
Keith's Avatar
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From: Lawrenceville,Georgia,U.S.
First thing I would do is check the following fuses under the hood on the drivers side fender: EGI COMP, EGI INJ, MAIN, and BTN. If all of these are good, then I would check for 12V at the Black/Yellow stripe wire on either the leading or trailing ignitor plug (with the ignition on).

If you do not have it, I would check the same color wire on the main relay. If it is there, you have a broken wire somewhere. If not, I would check for 12V at the Black/white stripe wire on the 2-wire plug connected to the main relay. If it is there, replace the main relay. If not, check the fuse in the second row, second from left (in the fuse box, 15A). If it is good, you have a wiring problem from the ignition switch. If you replace the fuse and it blows, you have a short somewhere going to the main and circuit opening relays. If it doesn't blow, it should crank now.

If you have it, check the 7.5A fuse (fuse box) top row (first) third from left. If blown, replace it. If it blows again, you have a short in the circuit to ECU pin 3J. If not, see if it starts. Going back to the 7.5A fuse, if it is good, check for 12V at ECU pin 3I. If it is good, your ECU is blown or you have wiring problems CAS to ECU, or ECU to ignitors. Also could have a bad CAS even though it meters fine.

Well, there you have it. Good luck!

Irv, Keith's dad
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Old Nov 30, 2001 | 01:40 AM
  #3  
Rx7-88na's Avatar
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From: Marietta, Georgia
From now on Im taking my car to YOU to fix... geezuz...That was a ridiculously detailed explanation...

you rock...
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Old Nov 30, 2001 | 01:53 AM
  #4  
Scott 89t2's Avatar
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From: Vancouver, BC, Canada
turbo2

how did you determine you had no spark? I couldn't get my friends car going the other day because it had the weakest spark. a timming light couldn't even pick anything up. after checking the coils for good voltage and resistance readings it turned out is was just the fouled spark plugs that were doing it.
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Old Nov 30, 2001 | 02:00 AM
  #5  
hypntyz7's Avatar
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From: usa
Got an old plug? Take off a leading plugwire and insert the old plug. Remove the rubber boot that covers the screws for the strut. Lay the plug 1/4" from one of the bolts. Have a friend crank it over, or watch it yourself. You should see and hear spark. IF you dont, youre getting no spark.

Ive been through this twice before. I did everything Keith pretty much described above. 2 days I couldnt get any spark. Was the damndest thing. I even had out the FSM wiring diagrams. Finally I found it. the afm was bad. I unplugged the afm and I started getting spark. I installed another and the car ran fine.

Leave the wire/plug experiment out until you finally get a spark, then replace it and your engine will run. Try cleaning the afm contacts, and then replacing. To test, you can just unplug the afm connector, crank her over and watch for spark to come back. IF it does, then you need another afm. Iave had no spark twice now, both times it was the AFM.

Let us know what you find!
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Old Nov 30, 2001 | 02:06 AM
  #6  
87_mazda_Chevy's Avatar
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From: Washington
rx i had the same problem and it was the egi comp i just had to replace it the 28 cost me $350 for it
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Old Nov 30, 2001 | 12:34 PM
  #7  
HAILERS's Avatar
HAILERS
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From: FORT WORTH, TEXAS,USA
Just talking about the fan.....it should come on. See page 50-38 of the 88fsm. The F-75 fan relay should relax and turn the fan on(fuse pulled) when the key is turned to on. The fsm is free on the web somewhere.

Last edited by HAILERS; Nov 30, 2001 at 12:36 PM.
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Old Nov 30, 2001 | 02:17 PM
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rx-lost 2nd gen's Avatar
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From: tx
THANK YOU!!!

I appreciate all the informative feedback! I am currently awaiting the arrival of my new ignition system..i.e.: C.A.S., T & L ignitors, & ecu. I will check all the suggested wires, fuses, etc. and get back to you with my results asap. One last bit- I ran the codes on her and the only thing that showed was the water thermo sensor. When I cleared that one, no others ran.
thank you...thank you... thank you!!
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