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DaveG
New User
Jan 5, 2008, 5:25 PM
Post #1 of 6
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92 Bravada will not fire
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Hey everyone, new guy to forum, but not so new to auto repair. This one has me confused, though, and need some help. 92 Olds Bravada, Vortec V6, with new cap, rotor, plugs, wires, and ignition module. Ran this fall when we brought it home, then it started dying after driving short distances around the block, but would start and idle. Now this was all before the new stuff we put on, and now has been sitting a few months. Went out to get it going for my son, and can't even get it to fire now. I have spark, and pressure at the fuel rail, but no fire. Even tried staring fluid into the intake and it doesn't even try to fire, just turns over. What's the deal? I feel stupid, cause spark and fuel should mean fire, right?
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way2old
Veteran
/ Moderator
Jan 5, 2008, 5:45 PM
Post #2 of 6
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Re: 92 Bravada will not fire
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Have you checked for compression? If it has sat for a while with the pistons in one place, it is possible you have lost compression. Remove the plugs and spray a little oil into the cylinders and turn the engine over a few times with the plugs out. Then install plugs and try again. It is possible the injectors were leaking and washed thse cylinder walls down causing loss of compression.
Being way2old is why I need help from younger minds
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DaveG
New User
Jan 5, 2008, 6:33 PM
Post #3 of 6
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Re: 92 Bravada will not fire
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I guess that could be possible, but on all 6 cylinders? It sounds like it has compression, you know, it's sounds tight when it's cranking over. I can't check it until tomorrow, but it does seem unlikely that all 6 have lost compression. It hasn't popped even once today. The battery was completely dead, but after being on the charger for a while, we finally got it to come back up, and while trying to start it, I had the jumpers on it from my Cummins diesel truck so it was tuning over just like it had a fresh battery. Just seems odd that it wouldn't even pop off on starting fluid. And, thanks for the quick reply, Dave.
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DaveG
New User
Jan 6, 2008, 11:33 AM
Post #4 of 6
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Re: 92 Bravada will not fire
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Ok, I've checked compression and it's fine, 165-180 psi. So what now? Other people I've talked to say that if the knock sensor is bad, it won't fire. I thought that all it was capable of doing was to retard or advance the timing a few degrees, not keep it from startig. Could it be the problem? Or, am I right?
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Tom Greenleaf
Ultimate Carjunky
/ Moderator
Jan 6, 2008, 1:10 PM
Post #5 of 6
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Re: 92 Bravada will not fire
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Hmmm? Spark, fuel (starting fluid test ok) and no start?? You said you already replaced the plugs. Has that been a while even if no miles? What brand was used? Have you checked for the plug to actually fire at the plug?
It's out there for a problem but if the plugs got flooded out bad they may look dry and ok and just not fire. Especially off brand non OE plugs.
They may need heating up with propane torch till red hot to really dry them out. Had a few over the years that the spark actually went thru the saturated porcelain without really jumping the gap. One so bad I had to leave plugs out and vent cylinders quite a while even before it ran and once it did the problem was over.
It shouldn't happen but I know it can. Gas we buy lately is part of the problem. Virtually every season piece of equipment I have won't start for anything without torching the plug or replacing it. Prob for storage is to run them dry of gas with that junk.
This is rare but there have been several fool me with this. All were GMs and that shouldn't matter. I think all were Champion plugs too which I refuse to buy again (they'll like me for that) for anything!
That's a possibility especially if the fuel injectors leaked down all the fuel and now even air dried have messed up the plugs.
Just a thought,
T
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DaveG
New User
Jan 7, 2008, 9:48 AM
Post #6 of 6
(3794 views)
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Re: 92 Bravada will not fire
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Hey, thanks for the reply and the info. I called home to my two sons and they are going to pick up some new plugs today and give it a shot. It has been a while since it has ran and my son did tell me that he put in some cheapo plugs, so hopefully you're right! I'll post the results later.
Thanks, Dave
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