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Discussion Starter #1
I have just finished rebuilding my 6g72 twin turbo motor and dropping it into the car, and it fired up shortly after priming the engine; however now will not start. It cranks, I have spark, 150psi compression, lots of fuel pressure and engine timing seems good. The engine seems to be flooding as the plugs are wet and oil has faint smell of gas. Can not get it started, it sounds/acts like a flooded engine, I have waited and pulled plugs to dry the cylinders out, then it kinda starts but then soon bogs down and stalls like there is way too much fuel. The injectors are oem and never replaced. I bench tested them and seem to be okay but not sure if there dumping too much fuel or injector timing and spark timing is off. Any help would be appreciated!
Thanks
Connor
 

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Sounds like you have checked the obvious. What, if anything, is aftermarket on the car? Have you tried starting it while holding it at WOT? That sometimes works to get a flooded engine started (lets extra air in).

Were all the plugs equally wet or were some worse than others? Could be a stock injector(s).

When you say timing "seems good" what did you check? Did you set base timing?
 

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Only think after market is a boost controller but that is set to be zero right now and a open downpipe. Have held it at open throttle and tried every gimic to get it started but zero results. When I did the timing belt all the marks and everything lined up and cranking it by hand it everything seemed good. When engine was put in the car checked base timing and everything was right. I did a vacuum hose reduction getting rid of the vacuum hose cluster on the top of the throttle body but everything that needs vacuum has been run correctly and the boost controller was installed and the blow off valve is in place. No vacuum leaks from any modifications. The injectors sat for at least 4 years but when bench tested they sprayed. However one could be stuck open. It seems like all the plugs are equally as wet. Car might have had some old bad gas in it, but draining the tank and purging the system then adding new gas to see if that helps.
 

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Sounds like you are doing everything right... How did you confirm spark?
 

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I could be way off base, but I seem to remember others after rebuilds having similar issues.
IIRC, it had to do with swapping intake and exhaust cams.

I believe there are markings on the cams to tell which is which.

Again, I could be totally wrong here, but just throwing out something I "thought" I've read a few times....

Bob.


It seems that if the cams are swapped the compression numbers would be wonky, but you claim yours are good.

Might be worth a read anyway....
 

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Hmm well if you have air, fuel, and spark, it sould like timing might be the next thing to take a closer look at. Maybe Bob's suggestion to confirm? However if that was the case it would be strage it started the first time. How did it run when it started?
 

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Discussion Starter #8
I have checked compression on all cylinders and have 155 across all 6 cylinders and the cams are in the right spot. Pulled all the plugs and dried out the motor still have spark to all plugs and still fuel pressure. Cranks fast sparks has fuel but will not start. Any ideas how to check other parts of timing or injector pulse/timing?
 

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Discussion Starter #9
When it started it ran not horrible only had it running for a minute or so but nothing seemed wrong or bad.
 

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Sounds like you have checked the obvious. What, if anything, is aftermarket on the car? Have you tried starting it while holding it at WOT? That sometimes works to get a flooded engine started (lets extra air in).

Were all the plugs equally wet or were some worse than others? Could be a stock injector(s).

When you say timing "seems good" what did you check? Did you set base timing?
The car also has a upgraded fuel pump could the fuel pressure regulator be over run and dumping to much fuel?
 

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Discussion Starter #11
The car also has a upgraded fuel pump could the fuel pressure regulator be over run and dumping to much fuel?
 

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Yes you can definitely overrun the stock FPR, especially if you have a hotwired pump. That seems like the next thing to check, especially if it seems like it is flooding.
 

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Discussion Starter #13
Yes you can definitely overrun the stock FPR, especially if you have a hotwired pump. That seems like the next thing to check, especially if it seems like it is flooding.
Do not have a hotwired pump just a slight upgrade from stock however I don't think that should over run it.
 
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