after changing an injector my 94 3.0 would not start, checked and rechecked everything, new most everything, finally found post on this site that talked about my exact problem of everything checking out, spark, ohms, fuel ect ect. and fixed by changing cold START plug wire. i changed wire and the truck started rough but running, noticed i had not put line from egr to egr modulator back on and put it back on and truck would not stay running. took it off and truck running rough. an unbelievable amount of hot exhaust blowing out of tube something wrong for sure. any suggestions?

 

The good news is that there is supposed to be hot exhaust from the EGR valve to the EGR modulator. http://www.ncttora.com/fsm/1990-1995...n/exhaustg.pdf Slightly less good news is that the CSI (Cold Start Injector) has absolutely nothing to do with the EGR. So you've got a cluster of problems all trying to hide each other.

Think functionally. Start by disconnecting the CSI wire at the injector. It should be harder to start (depending on how cold it is), but it should run fine. If it won't run after warm-up, your problem is not the CSI.

Temporarily disconnect and cap (at the throttle body) the two vacuum lines to the modulator. The truck will run fine w/o the EGR (as many on this site will attest; you're just pooping into the air we all breathe), so if disconnecting the vacuum doesn't change things then the EGR is not the issue (be sure to hook it back up).

Last, if you managed to miss the EGR valve-modulator connection after you "checked and rechecked everything," maybe you need another set of eyes. Something isn't hooked up right.

Good luck!

 

the truck did not run until i changed CSI connector. when i went to start after CSI repair truck started first time in 2 weeks butr was running rough so I noticed line from egr tube to modulator was off and when i put it on truck would not start so i took it off. I understand hot gases come from egr but this is an amazing amount and extremely hot and truck won't start and run with tube connected. Was wondering if I have a line from somewhere else connected wrong so more gas and or air is getting to egr tube than normal. also wondering if that small tube not the large one is suppose to handle that much exhaust fumes ? thanks for the link it will help