hi,was drivin as usual today,then engine was runnin rough>>>!
while going around 55mph...pulled in at home,it wanted to die out whilst idling!!!?checked the spark plugs-they were good.re-installed my original EPROM-still didnt do it!???wires checked out OK too.
now i had it rebuilt maybe 20k ago and since then NO PROBLEMS....everything was replaced...i found NO trouble codes from the self-diagnostic feature either!
i havent been able to run high octane gas as per the TBI EPROM that i had in it,i thought maybe it was from inferior gasoline causing it to run that way???but to no avail....still runs ultra rough! any thoughts third gen heads????i really been trying to finger this 1 out, I DO NEED EVERYONES THOUGHTS FOR A SOLUTION
PLEASE,TY-BRAD

 

Rough as in a miss, a knock, a rattle???????

 

it seems to be more of a miss than anything....no knocks or rattles.i have new tbi injectors i installed also!still the samething happening....i wonder if it could be vacuum or maybe the EGR???I WONDER?????????????ANY THOUGHTS...........????

 

things that always have made my car miss like crazy. this way maybe at least give you some ideas of where to start

plugs gapped too far or needing replaced. found out looking good also doesn't mean they are good. might need those replaced. also double check your gap. too large of a gap will cause problems

spark plug wires. easy check on those though. grab a multimeter from someone and check their resistance. not 100% effective on finding out if they are bad but hey it still might lead you to theright direction if the resistance is very high or you don't even get a reading. your resistance reading I'm assuming is going to be around 6k-15k ohms but I'm not sure the specs. someone else might be able to give you the info on the specs

timing. having the timing misadjusted will always cause problems.

get a cheap vacuum gauge to read your vacuum.

try a compression test if you get a chance also


another thing you said you had it rebuilt 20k miles ago right? that means you should of had some driving time on it. did you change anything around the time it started messing up? add something try working on something anything?

 

forgot about the EGR that you brought up it can cause some problems also if it is sticking

 

WELL I CHANGED THE PICK-UP COIL AND it still runs the same!!!i did notice the brake pedal was hard to depress when i took it for a test drive!!!im thinking it could be a power-booster or a vacuum problem possibly????? any thoughts FELLOW 3RD GEN HEADS????

 

What sort of chip tuning have you done? If the answer is none than I would start there.

 

start pluggin vacuum lines till something changes.

 

you need to determine if its one cylender doing it or a random miss fire... then we have somewere good to start from... easiest way to find that out.. wile its running, pull the plug boot of the plug and see if it evens out...... steadies out..... how far it bogs down compared to other cylenders doing the same procdure on them..