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Very Loud Backfire Engine Died Now wont Start Any Ideas

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Old 10-10-2011, 07:35 PM
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Black51
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But did you check the IC couplers. You really gotta make sure they're on and they're easy to miss because they often pop off on the bottom side. When a coupler pops off while under boost it's quite a catastrophic experience, lol. It seems like the engine has just grenaded when it happens. But if you can just get the car started and it sputters and struggles, and especially if you give it throttle in that state, and it stalls, then it's most likely an IC coupler.

If you were under boost when the big bang happened, it would make sense a flame would shoot out right when the car stalled, since there is still that last bit of mixture undergoing combustion.

Otherwise, when it starts and sputters, does it sound like there are any dead cylinders? You'd notice it if there were any dead cylinders in the distinct sound it makes.
Old 10-10-2011, 07:50 PM
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I did inspect those earlier. I just went out and looked at the IC couplers again. No opening on the bottom or top. I took them off anyway and then put them back on. No change. I dont notice any dead cylinders. I did get one major backfire while trying to start the car today again during one of the times I tried restarting. I also am getting smoke out the tailpipe when I first try probably due to flooding the cylinders with fuel while trying to start. The car does make some noise sometimes when trying to start. I get some loud popping near the back of the car I imagine it is excess fuel
Old 10-10-2011, 08:07 PM
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Pull the j-boot off and see if there is any turbo shaft play. Either that or recheck the timing to see if the belt slipped any teeth.
Old 10-10-2011, 08:48 PM
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i would check the T belt.
Old 10-10-2011, 10:10 PM
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Gotta check TDC vs cam timing at this point... There isn't much else left. Did you remove and closely inspect the rotor while you had the cap off? Check with Josh for a procedure to test the MAF and MAP sensors? Check ALL (large and small) lines going to the intake manifold including the boost banjo line and the "pipes" that the ISV and brake booster hoses connect to... Check for blown (squeezing out) intake manifold gaskets... could the MAF pipe silicone hose have slipped off the turbo inlet?
Old 10-10-2011, 10:37 PM
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Yes I tried to check tdc when I had the cap off but could not see under the car for the lower mark. I will check that tomorrow when I jack the car up. Belt looked good. Did not remove the rotor but wiped it down a little. I think the belt must have slipped too. All the major and minor hoses in the car were inspected and are connected. I really appreciate your help guys. I will let you know if the timing is off. Matt maybe I need to call Josh to see if he knows a way I can test the MAF and MAP sensor.

If my belt did slip what should the next step be? I have a spare head In the garage.
Old 10-10-2011, 10:38 PM
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Yes I tried to check tdc when I had the cap off but could not see under the car for the lower mark. I will check that tomorrow when I jack the car up. Belt looked good. Did not remove the rotor but wiped it down a little. I think the belt must have slipped too. All the major and minor hoses in the car were inspected and are connected. I really appreciate your help guys. I will let you know if the timing is off. Matt maybe I need to call Josh to see if he knows a way I can test the MAF and MAP sensor.

If my belt did slip what should the next step be? I have a spare head In the garage.
Old 10-10-2011, 10:42 PM
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Reset the belt correctly and pray
Old 10-11-2011, 02:21 PM
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Take a rubber mallet to the Cat, classic symptoms of a collapsed converter core.
Old 10-11-2011, 02:32 PM
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Originally Posted by Clown
Yes I tried to check tdc when I had the cap off but could not see under the car for the lower mark. I will check that tomorrow when I jack the car up. Belt looked good. Did not remove the rotor but wiped it down a little. I think the belt must have slipped too. All the major and minor hoses in the car were inspected and are connected. I really appreciate your help guys. I will let you know if the timing is off. Matt maybe I need to call Josh to see if he knows a way I can test the MAF and MAP sensor.

If my belt did slip what should the next step be? I have a spare head In the garage.
You know there's an inspection hole on the top of the bell housing, right? Just make the line next to the letters "OT" line up with the little finger thingy sticking out in the hole... that's TDC on the crank.





Pics courtesy of clarks-garage.com
Old 10-11-2011, 03:45 PM
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Ronin - Thanks but not running a Cat right now otherwise I would try that. Have a Full 3" on here.

Cracker - Yes I almost forgot about that inspection hole. I don't have a stock flywheel and have an aftermarket aluminum on there. Not positive but I dont think I remember a line on there but know that I am thinking about it I think there had to be one to help install it properly?? I will check it out tonight when I get back to the car. If not I will check the mark on the front of the crank.

What is the margine of error on these cars, as far as the belt slipping a few teeth? I don't hear any ticking or banging but maybe everthing allready bent and not hitting now. I will report back to you all tonight at some point. Thanks for everyones help!!!
Old 10-11-2011, 04:40 PM
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Mine did exactly what you described a couple of months ago. It turned out to be a faulty O2 sensor, which caused the engine to run extremely rich. As a result, your plugs are probably fouled and will need to be cleaned.
A few weeks after having that fixed, I had the intercooler hose pop off at the intake, and it exhibited the same symptoms (it stalled on the track, and when I cranked it, it would fire up but immediately stall again). As others have said, inspect the IC hoses carefully, take them off, check each one for cracks then reinstall it (even mark it when you put it back on to make sure it doesn't move).
Old 10-12-2011, 08:18 AM
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Well I did not have much time to look at the car last night but I checked the timing belt for TDC. Everything seems to be linging up pretty dead on. So I do not think I skipped any teeth. I am not sure what to do next. Maybe try new Speed sensors and another DME. Do you guys have the white timing allignment marks on the lower timeing belt sprocket and the other on the side of the engine case?

Quinlan - You say the exact same thing happned. Would your car not start and run until you replaced the O2 sensor and fouled plugs? I just replaced my O2 sensor a few weeks ago with a brand new unit. It seemed to run great for a few weeks. Maybe it just went bad. I think I saved the old one and could possibly throw it back on there to see if it fixes the problem.
Old 10-12-2011, 01:47 PM
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If the plugs were cleaned, it would start and immediately stall. After a couple of tries, it wouldn't start at all. We could smell gas. We pulled the plugs and they were fouled already. If you have fouled plugs, it would point to something making the car run rich....
I would put the old O2 sensor back in - it is a cheap test to see if it is the culprit.
Old 10-12-2011, 02:23 PM
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Wondering if you have an aftermarket Air Filter? The K&N wire mesh type, - filter oil has been known to foul the MAF sensor wire and cause a rich condition.


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