Engine Help

[lndshark]

OK. Dont know why I try to work on my car, seems like something like this always happens. about a week and a half ago my "new" 93 MTX starting surging when i was driving it. very intermitentaly, every other minute or so. So i think to myself, ah ha, must be the IAB. So i was planing on taking the manifold off anyway, might as well clean it out along with the IAB. I also figured that i would change plugs and wires as long as i had easy access to them. So i bought new plugs autolite ap3924, i know some of you will crucify me over this, but i found several people that say they work great for them. New wires, some premium brand, 100 bucks with a mechanics discount, my friends. I also plut in new intake manifold gaskets, and a new throttle body gasket. when i put the manifold back on i wasnt sure if it was seated right. i could push on one corner and it would move a little bit. on the oposite corners though, it wouldnt move at all. I went ahead and bolted it down, everything lined up and went back together. My battery was drained so i jumped it this morning. right away it started running like crap. sputtering, it would idle up to like 1200 then drop to 200. it would continue this for a minute or so, and then it would die. I checked everything over again and found the little black canister that is on the back of the manifold had a vac line that was coming out that wasnt connected. reconnected this but nothing changed. it will start up idle roughtly and jump all over the place. when i give it gas it will shake and sputter. what can this be. Anybody have any ideas. I could sure use some ideas.

thanks

brian

 

[ckinart]

when i put the manifold back on i wasnt sure if it was seated right. i could push on one corner and it would move a little bit. on the oposite corners though, it wouldnt move at all. I went ahead and bolted it down, everything lined up and went back together.

My first thought on reading this is that you have a vacuum leak. When you set the intake manifold in place, it should rest flat and not "rock" in any of the corners. You have to be careful not to pinch any hoses/lines under it, and be certain that it is sitting flush before you torque it down.

Unless someone can give you more definitive advice, I'd suggest you remove the intake manifold again and be certain that it's sitting flush before torquing it down.

Good luck!

 

[Dr. Tweak]

Yes, it should not move AT ALL. You have a serious vacuum leak.

Follow the instructions on my site in the Upper 60K section to reinstall it.

 

[lndshark]

Thanks for the input guys, that was what i was hoping to hear. I didnt think it was right to have any play in the manifold. Its been years since i had one off. Have to take it off and check again.

JD, ive already made use of your awesome site. When i was putting it back together, albeit incorrectly, i couldnt find a vaccum line, so i looked at your pictures and disassembly instrucitions and found the bugger. As a fellow SHO enthusiest I would like to tell you how great your site it, just in case you dont hear it enough. I would like to be sho adept to perform all my own maintence down the road. And you site is definately a step in the right direction. Just bought my second one, the 93 i managed to screw up, and i can tell you that for some years anyway, i will never own another car. My fiance wanted to get a grand prix, or grand am, or something etc. But i flat out told her, the only car I am interested in in a SHO. Anyway, thanks for the great site, if i can do anything, can imagine what, just say the word.

thanks again

brian