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No spark or injector pulse:(

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10K views 3 replies 4 participants last post by  LT Scholz  
M
#1 ·
Left my car sitting for a night after 5 minutes of driving and all of the sudden it doesn't want to fire. I for sure have no spark or injector pulse at all.I tried spraying start stuff into the throttle with no luck!. Next I checked fuel pressure and the filter, that was fine. Then I took things to the extreme and bought a crank sensor and swapped the ignition module and still it won't start. Also tried disconnecting the mass air sensor and the temp sensor to see if it would fire and still no luck at all, all fuses look fine as far as I know unless there is a bad relay somewhere. Does it sound like the optispark could be bad and would the optispark being bad cause no injector pulse? I had a buddy rebuild a new one for me 3 months ago but maybe he did something wrong and it just randomly died after sitting for a night? Car is an A4 96 trans am with a vented opti, the vacuum hose to the vent on the opti isn't connected however but I haven't drove it in the rain or over anything wet recently,

If it is the optispark, anyone here have experience buying cheap opti's off ebay? Ive seen a couple for a 130 after shipping which sounds too good to be true!

http://www.ebay.ca/itm/260954276940?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
 
#2 ·
There is a Sticky Thread above this section about how to diagnose bad Opti before you buy one.

Also I didn't see any mention of a code scan. I would start with a code scan before you start throwing time and money at parts - your car maybe trying to tell you something through the codes.

As for cheap opti's on eBay - most people swear at them, not swear by them. If you have to buy a new one, I would go with the ACDelco or MSD - they are the best.

You may also need to change your opti harness - no spark can be caused by this.
 
#3 ·
Is by chance your security light on? That would prevent you from running also, even though it doesn't disable ignition system. I would scan for codes as the 3 ignition biggies don't light the ses. They are opti low res- kills ign and fuel injectors. 2 icm related codes also kill ignition and fuel injectors.
 
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