91 grand prix hard to start and sounds like its missing

[nvs2b1]

well i found one problem with my 91 grand prix! i started a post about a month ago and got a couple of responds. FINALLY, i decided to check the timing gear & chain . when i opened the timing cover,, i found the chain broken and the gear was missing a tooth!so decided ,,what the hell, i replaced everything else,,, beter to the timing gear & chain!it takes about an hour to do(not to bad).now with everything back together,,i decided to crank the car up! yes it started!! but i have to have the throtle to the floor and it runs like a bag of you know what!.lots of black comming out the muffler.ok ,,, not over yet!! decided to get the timming rechecked and it was rite on! also,, i am getting good spark and about 150 to 160 compresion.now this is a 3.1 multiport (lbp). is it possible that the firing orer is wrong or different?because to me that's what it sounds like! pls help nvs. tx
you can email me directly if you think you have a solution. greatly appreciated. [email protected](remove nospam)

[richtazz]

If all 6 cylinders are at that compression, then a bent valve is out of the question. It is possible that you set the cam 180 degrees off. The crank turns twice for every cam rotation, and if the crank was not a tdc for #1 cylinder, but instead on the #1 exhaust stroke, that would cause your poor performance due to the spark timing being 180 off. On a distributorless ignition, the coils fire on both the compression and exhaust stroke for each of the two cylinders on a coil pack, but the spark is much weaker on the exhaust stroke fire.

[nvs2b1]

well from what we did it would be very noticable if i was off by 180 ! there is a dot on the top timing chain gear and one on the bottem crank.they are both at 12 oclock. i would think that is top dead center on #1! or would there be some way its off? we checked twice!

[richtazz]

a distributorless ign system fires differently than a distributor. Exampe, cylinders 1 and 6 are opposite one another, and fire off the same coil pack. IF your 180 off, the coil will still fire on the compression stroke, but with about half the voltage of normal. That would cause your black smoke and running like doo doo. Double check your timing gear alignment and make sure the dots don't face one another, instead of both at 12 o'clock

[nvs2b1]

well on saturday. we did it the first time and on sunday we took it all apart to see again,,and they were both @ 12 oclock!

[richtazz]

I consulted a repair manual, and your dots should be crank at 12 o'clock, and cam at 12 o'clock, so you're good there. Have you checked for any vacuum leaks, double checkall your hoses and make sure you didn't forget to hook up a vacuum line. My other suggestion would be to check fuel pressure with the engine off and running, to make sure your pressure isn't dropping once the engine starts, indicating a bad fuel pressure regulator.