93 backfired into crankcase?
Thread Starter
6th Gear
Joined: Sep 2009
Posts: 6
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93 backfired into crankcase?
My 93 cranks but wont start.It has spark and 42 lbs of fuel pressure. I tested injectors with a noid light and they appear to be pulsing.It sometimes acts like it wants to start but then catches and backfires through intake.last time I tried to start it , it backfired and blew both valve cover gaskets out. Maybe it jumped time ? Please help.
Thread Starter
6th Gear
Joined: Sep 2009
Posts: 6
Likes: 0
No mods.Car was running good then developed a slight miss which went away under acceleration. Over a period of about 2 days miss would come and go (at idle).Then car started missing and backfiring under exceleration.Once it started to run rough at cruising speeds I brought it home and parked her.Next time I tried to start, it cranked over but would not start. Car has 95000 miles on it.(plugs wires and coil have 4000 miles on them)
Drifting
Joined: Nov 2005
Posts: 1,324
Likes: 5
From: Charlotte NC
Thread Starter
6th Gear
Joined: Sep 2009
Posts: 6
Likes: 0
93 backfired into crankcase?
Last edited by Bigtime1993; Sep 25, 2009 at 01:55 AM. Reason: not enough info
Former Vendor
Joined: Nov 2006
Posts: 2,482
Likes: 3
From: Carmichael ca
TDC #1 cyl and see if the rotor is pointing at #1. Sounds like the timing is way off. The blowing the valve cover gaskets out is concerning. If the timing looks close, I'd suggest a compression test.
Drifting
Joined: Nov 2005
Posts: 1,324
Likes: 5
From: Charlotte NC
- The opti were forced on incorrectly
- The plug wires are incorrect
- A seriously damaged opti
- Incorrect timing of the gears
Melting Slicks
Joined: Apr 1999
Posts: 2,521
Likes: 4
From: Windham, NH
This may or may not be an answer to your question but I had simular symptoms with my yellow 93 a few years back. I figured it was the original OptiSpark going bad. I installed a new MSD unit and I STILL had the same symptoms. LONG story short, it turned out to be the Ignition Control Module that is mounted with the Ignition Coil on the front of the passanger side Cylinder Head.
Jim
Jim
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Thread Starter
6th Gear
Joined: Sep 2009
Posts: 6
Likes: 0
This may or may not be an answer to your question but I had simular symptoms with my yellow 93 a few years back. I figured it was the original OptiSpark going bad. I installed a new MSD unit and I STILL had the same symptoms. LONG story short, it turned out to be the Ignition Control Module that is mounted with the Ignition Coil on the front of the passanger side Cylinder Head.
Jim
Jim
Le Mans Master
Joined: Oct 1999
Posts: 6,366
Likes: 34
I had a dead alternator. took it back to get a new one. It tested fine. I told them I am not leaving with that POS so they gave me a new one. my car was fixed.
My trucks battery was shot. took it back to get a new one. they said it tests fine and they would charge it. I said bull**** but do what you want. It spewed over in 10 mins on the charger. I got a new battery and no more problems.
I dont know if that module could be one of these things that tests fine. I dont know if the operator could be the issue. I am just saying, dont let the module slide since they said it was ok.
I would ask if they would accept a return on the module if you buy it and your car is still broken. buy it and try it. I have had a few guys return electronic parts at the auto parts store. I know napa does not want to take back stuff like this after you buy. pep boys guy said why not.
I am in line with concern about the blown valve cover gaskets. I would probably buy a compression tester, or see if you can rent one (for free) and do a test. that would be bothering me big time.
Melting Slicks
Joined: Feb 2008
Posts: 3,286
Likes: 6
From: Palm Beach
I am at a loss as to how that could happen. There is not a route from the cylinder to the crankcase or valve covers unless you have a TON of blowby.
My 93 cranks but wont start.It has spark and 42 lbs of fuel pressure. I tested injectors with a noid light and they appear to be pulsing.It sometimes acts like it wants to start but then catches and backfires through intake.last time I tried to start it , it backfired and blew both valve cover gaskets out. Maybe it jumped time ? Please help.
Last edited by MK 82; Sep 28, 2009 at 04:44 AM.
Thread Starter
6th Gear
Joined: Sep 2009
Posts: 6
Likes: 0
I know it, I can't figure it out either. Car was running great, it doesn't smoke or use oil. The only route from cylinder to crankcase I know of would be a blown head gasket, but how could I blow a head gasket by cranking engine over ?
Melting Slicks
Joined: Feb 2008
Posts: 3,286
Likes: 6
From: Palm Beach
A blown head gasket usually vents itself to the water jacket or the outside.
Melting Slicks
Joined: Apr 1999
Posts: 2,521
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From: Windham, NH
I went thru the same situation when my Ignition Control Module went bad.
Jim
Le Mans Master
Joined: Mar 2001
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From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
Cruise-In III Veteran
Cruise-In IV Veteran
St. Jude Donor '12
A new ICM and coil are cheap. My 92 had a similar issue and I thought it was a dead opti.
Friend with a 92 suggested replacing the coil and ICM. I did and it started right up.
Unfortunately the parts stores cannot test your ICM to verify good or bad with any consistency.
Friend with a 92 suggested replacing the coil and ICM. I did and it started right up.
Unfortunately the parts stores cannot test your ICM to verify good or bad with any consistency.
