Nice bright spark but no start
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From: In the garage fixing LT1
Nice bright spark but no start So I'm driving along when out of nowhere my car starts cutting out if I push the pedal too hard. I made it to a shopping centre where it just sputtered and died. I had to call a tow truck.
When I get home I go through everything. I'm getting spark, I seem to be getting fuel because it bleeds out of the release valve and the timing chain isn't broken. I haven't done a fuel pressure test yet because I need the adapter.
Is it possible to have a strong spark and still have a messed up Opti? Mine is the MSD unit. I can't see how I can have spark like that and absolutely no ignition. Anyone here know what's going on?
When I get home I go through everything. I'm getting spark, I seem to be getting fuel because it bleeds out of the release valve and the timing chain isn't broken. I haven't done a fuel pressure test yet because I need the adapter.
Is it possible to have a strong spark and still have a messed up Opti? Mine is the MSD unit. I can't see how I can have spark like that and absolutely no ignition. Anyone here know what's going on?
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From: In the garage fixing LT1
Well, the coil is a new MSD unit, but I never changed the ICM and it has never been changed in 100,000 miles. The TPS I don't know about. I'll try one at a time. This is frustrating.
a bright blue snap is good spark, anything less than that= Icm or coil issues normally. Had a similar issue in my dads 434sb nova. It has msd digital 6, blaster coil, pro-billet distributor. The spark looked good to the eye, but when we compared it to his 482bb chevelle(same ignition set-up), the spark was noticeably weaker. Turns out the compression of the motor was blowing what we thought was good spark out! Changed the coil and instantly it fired up! Msd has had issues with there coils and ignition boxes! Hell I had a brand new msd coil go bad within a couple month's,so I put the stocker back in and left it. Try to stick with factory parts as much as possible. Quality control is really starting to cast a black cloud over aftermarket component's!
I'd put money on your fuel pump. Check that fuel pressure via the schrader valve and see where that gets you. You said it was bleeding out? It should have a little pressure behind it. Might change the fuel filter before you do the pump. There's always a slim chance that'd fix it and its a heck of alot cheaper than a pump. I'm having a hard time thinking its iginition when you have spark and aren't getting it to hit. It's almost gotta be a fuel issue of some sort.
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My MSD coil failed in less than 50 miles but still had spark. If you have your stock one, put it back on and see if that fixes it. Just because it's new doesn't mean it's not defective.
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As mentioned it could be the TPS. When mine went out it went out in "flood mode" so it wouldn't spray fuel at start up. I had good pressure and everything at the rail but it wouldn't spray so the car wouldn't start.
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From: In the garage fixing LT1
K. Found it. Definitely a fuel problem. Just ordered the pressure testing kit. Dumped some Quik-Start into the manifold and she chugged a little, blew some air in and didn't smell gas so she's not flooding. I'll know by the end of the week, pump or regulator. Damn, this is no fun.
K. Found it. Definitely a fuel problem. Just ordered the pressure testing kit. Dumped some Quik-Start into the manifold and she chugged a little, blew some air in and didn't smell gas so she's not flooding. I'll know by the end of the week, pump or regulator. Damn, this is no fun.
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From: In the garage fixing LT1
Tested the pump today. I got 40psi, right where it should be. Then I tested the injectors with my injector test kit and they check out fine. I swapped the coil and that didn't make a difference. There is ignition but it's very faint. I'm going after the fuel regulator next. Only other thing is the ICM. I'll have more time tomorrow. Man, this is a bitch.
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From: In the garage fixing LT1
For those interested, it's nine months later and I finally got around to working on this car again. I discovered that though the spark was bright going into the optispark, it was considerably reduced at the plug. Swapped the opti and the same condition continued. Tested the coil and it came out weak. Changed the coil. Vrooom, she started right up. The obvious problem? The brand new MSD blaster coil, apparently. This will end my use of MSD products.
