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2001 Pontiac Grand Prix Intake Woes

F

fordpickup0713

New member
Hello Everyone, I am new to this Forum and was hoping to get some much needed help, ok so my problem is a big one I think.
About a year ago I had a mechanic repair a leaky fuel line connection at the injector rail, after that I took my car to a dealership to get it inspected and have them properly replace the fitting for the fuel line as the mechanic just bandaided the connection with an extra oring, so the technician at the dealership said all he did was drive the car into the shop and turn the car off, after that when he attempted to start the car the intake manifold exploded, for reasons I won't go into the car sat at the dealership for a year and now I am attempting to repair the car myself at home, I removed the intake manifold and everything related and replaced everything necessary, now all the car does is backfire when I attempt to start it, there are no codes stored in the computer, there seems to be fire since the car is backfiring and same for fuel, I was thinking that the fuel may be old but it is good enough to backfire, it should try to fire then, I am desperatly in need of help, Thankyou in advance
 


I would absolutely replace the fuel.. Its brobably backfiring because yes there is fuel there, but also a lot more moisture in the mix, so its trying to fire but it can't..

I would change the fuel.. Sitting for a year is never a good thing.
Also replacing the fuel filter wouldn't hurt either.
 
Ok so 1st of all I was definitely planning on doing the fuel, but in respect to my problem, even if the fuel was so bad it would not run, that would not explain the problem in the first place a year ago that made it explode in the first place, and why would bad gas make it backfire through the intake now, second of all I definitely checked and double checked yesterday the firing order you really cannot change the order because it has coil packs but the wires are plugged in and routed correctly, So STUMPED, really could use some help
 
You can screw up the order with coil packs. I've done it plenty of times.

Ensure your bottom coil is 1/4, middle coil is 2/5 and top coil is 3/6. I've seen people swap them around to check for stuff and never put them back, then hook up the wires as if the coils were in the right places.

It's odd you can't get it to fire.
 


You said you took it apart down to the lower intake gaskets and put it all back together yourself. Might get a can of carb cleaner and spray atound the lower intake and other areas to check for a major vacuum leak. Chteck the orings in the fuel injectors as well, when those go bad you tend to get lots of missfire.
 
Ok so first of all I did try spraying starter fluid in and all I did was start a fire, I am afraid to spray it in again with the new manifold on because I do not want to blow up my new manifold, I am assuming since there is backfiring that the gas is good enough to fire and since it is backfiring through the intake something is wrong with the firing order or timing chain or one of the position sensors, It is entirely possible second of all that someone at some point changed the coil pack location but according to all the diagrams I have seen and what you posted I believe they are right but I am going to double check today at lunch, the only thing different about what you said and what I have is that I have 1/4, 5/2, and 3/6, not sure what my problem is but I am fairly sure it is firing as it is backfiring, Third of all Yes I took the old destroyed upper intake off and replaced it, it is possible that I do not have a good seal I guess but I believe it is all sealed well, the injectors got brand new orings
 
Looking down at the coils, from "top" to "bottom" you have 6-3, 2-5, 4-1 Cyls 2,4 & 6 are nearest the firewall, so 1,3 and 5 are closest to the cooling fans.
 
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