My turbo went 2 days ago, got very loud, so I grabbed a used one that was laying around my garage. Took me 2 hrs to figure out how much work there is involved with taking the old one off.
It's off, cleaned the old gasket off the head, got a new gasket, put the new/old unit on, had a hell of a time putting the rail with the fuel injectors back on, but succeeded finally.
Any hoo.....
Reconnected my battery up, got into the car, turned the key, motor turned over, car sort of started, back fired ... now it will not start, turns over, You know .... crank, crank vroom vroom, then stalls, once it kept on going, but vibrated the whole car really bad, until it stalled, and since then, does not start, does not back fire, just turns and turns, with the odd vroom and immediate stall out, after a few cranks, it actually stops cranking, like someone uses a vise grip and stops it cold in it's tracks.

I have really checked everything over, everything is connected, any ID's would be appreciated... I'm at my witts end.

Chuck

Did you mess with the plug wires?

I'm super confused by this. You swapped superchargers? You were taking a gasket off the head? Were you removing the lower intake too?

Herc offers some good advice. Backfiring usually means out of time or plug wires on the wrong cylinders. Make sure all your sensors are plugged up. Excessive cranking will not only drain the battery but if you don't let the starter rest, you can burn it up. If the car isn't starting, constantly cranking it isn't going to fix the issue.

No, I just unplugged 3 plugs from the coil packs, but I did number them, and of course used this site to get firing order to verify the plug order.... Herkman ...

Rook., I just replaced the gasket under the supercharger, and the gasket for the throttle body. I checked, rechecked and again checked all the connections, they are connected. I'm quite confused, I'm not a mechanic per sai, but I do know how to do regular maintenance, and a bit of this and that... I'm wondering if maybe the fuel injectors may of got damaged or plugged somehow, but again, as far as my common sense goes, the motor should still turn over easily. No?

You either have your wires on the wrong coil packs so they're not firing when they're supposed to or you didn't seal up the coolant ports on either the lower intake manifold (yellow o-rings) or the TB side of the blower and you're ingesting coolant.

I use RTV for the TB so I don't remember if its just a gasket or gasket and o-rings.

Wait... so you don't have a turbo?

Did you pull the supercharger and LIM? What went bad in the first place?

He has a supercharger, and by head I think he meant the lower intake manifold gasket surface and the supercharger gasket surface.

Just got back from work, .... I do have a super charger, my car is a '98 GTP stock with 286,000km on original 3.8.

This is my 3rd s/c change, the one I just took off was making a bad banging noise, I thought it was the top end of the motor, but I had a pair of Younger ears listen in, and I was informed it was the s/c.

I bought a new gasket for it, but in re to the yellow o rings, I did not get new ones, so I just kept the old ones in it. I had a friend of mine clean the injectors, so in the morning I"m going to install them, and keep fingers crossed.

I am not sure if there is a way of telling if I'm ingesting coolant as Hutchinson suggests, but I'm going to throw a guess out there as a "No", due to the fact of new gaskets.

I'm at a loss for sure, 'cause it was running fine till I did the exchange of s/c 's

I'm wondering if the s/c was fine in the first place and my second pair of ears mis-heard the sound and it actually was motor top end!!!