missing when under boost

[beefylocks]

My 93 Typhhon has 140k on it. I am experencing missing when under boost when at WOT. I am a bit confused because it will turn 4000 rpm in first gear before missing and stumbling, but in second it will only turn 3000 rpm, then in third it will only turn 2000 rpm. It has a slight miss in park, and i only notice the problem at positive boost. I have checked the fuel pressure and its at 40 psi, i changed cap, rotor, wires, and the control module in the distributor. i would appreciate any feedback

thanks

 

[V6 Kompressor]

The higher the gear, the more loaded the engine gets and the more strain that is put on the engine... did you try a coil... what cap and wires did you use... the cheaper sets are junk and won't last long at all, especially the 7mm ones that wall-mart try's to sell. Do you have access to datamaster or a good scantool.. check for knock retard, piss poor gas ect... You can check for missfire at night, with the hood open in a dark area. Have someone put the truck in gear (you preferably) and let someone stand from the side while you bring the engine rpms up (like you were on the starting line at a dragstrip) and watch for arcing around the plugwires, didtributor and coil areas. A bad set of wires or broken plugs will give you a nice light show! Hope this helps...

 

[beefylocks]

yes i did replace the coil and i used the conrad cap and AC delco 7mm wires and i used the c42ts plugs. i have no datamaster or scantool i did time the truck (with tan wire thingy) and its dead on i use 91oct i live in cali so thats as good as it gets (i did put 104 octine booster)
i did the spark test (the one at night hood up) and all looked good. i was thinking it maybe could be the ecm but i really dont know

My truck is all stock (i think) but i did the 160ther and changed and hotwired the ic pump and got k@n air filter

 

[leroy]

The fact that it misses at 4000 in 1st, 3000 in 2nd, and 2000 in 3rd makes me think fuel pump or filter. It also sounds like most of your ignition stuff is new, although I'm a little suspect of the AC wires.

Jim

 

[InvisiBill]

I had pretty good luck with my AC wires, which I think may have been stock, up to 100k. I think they may have been 8mm though... Might want to try some other wires or something. Also make sure the cap is on correctly. I've had it seat funny on my S-10 before, and know someone did on a Ty too...