I have a '92 5.0 with the following mods: 1.7 roller rockers, accel 48,000v coil, adj. fuel press. regulator, cold air intake, 9mm motorsport wires, BBK off-road h-pipe, flowmasters, 3.73 gears, pro 5.0 shifter. Here's my problem. I installed the fuel press. reg. and the coil at the same time and now the car feels like it picked up 10 hp untill I hit 4500 rpm. It pulls hard untill then and seems to "run out of motor" sort of speak. It stumbles at high rpm and makes no more power. The fuel press. with the stock regulator was 35 with the vac line on. I set the new one the same to start with. This problem is new since the coil and reg. install. the timing is set at 12. I was low on gas when i test drove it and it had shell gas in it. I filled up with Amoco and it got a whole lot better, but not gone. Any ideas would be appreciated!
HIGH RPM HESITATION NOW
- Thread starter MSTANG5O
- Start date
ECU5.0
Banned
it could just be running out of steam. if you have stock intake. the 1.7 rockers are letting out more air than is coming in. i dont know thats just my guess.
Installed in the right direction? All this replace to try to cure this problem?MSTANG5O said:
What kind of coil? Have you put the old one back on to rule the new one out and same for the regulator? Any time you make a mod and the car runs worse then when you started, always try going back if it's easy enough to do.
The car runs much better all the way around after the mods with the exception of the high rpm stumble. Pulls real hard untill about 4500-4700 rpm. I lowered the fuel pressure a little and it seemed to help, but now it's lower than it was stock. Stock was 35 vac. on. Now it's 30 vac. on. I can try going lower, but why would lower fuel pressure help that? It also seems to pull harder with lower fuel pressure. Any suggestions or comments are appreciated! Thanks everyone!
ECU5.0
Banned
it pulls harder because its running lean which makes more power....but is bad for the engine because it runs hotter and other reasons which i dont know. i was having the same problem you are having for a while and couldnt figure out until this weekend when my friend looked at it and noticed my #3 wire had been sittin on the header and wasnt getting spark. stupid me, but you might just want to check all the wires to see if thats the case.
PROBLEM SOLVED! Accel coil was no good. second one I've had problems with. put the stock coil back in and the car runs fine. No hesitation. Set the fuel pressure down to 40 vac off...30 vac on. Runs great, pulls hard all the way up. Got an MSD blaster coil on the way. Maybe I'll have better luck with it. Will post results with MSD coil in. If anyone has any ideas of why it would run worse at top end with a higher voltage coil rather than the stock one (other than the Accel was bad) let me know. Thanks guys!
Man, I have been racing cars for a long time. Screw all Excell and MSD equipment. If your coil needs to be replaced, go to the dealer and get a new one. There is a big difference in the quality of Factory parts vs most garbage aftermarket parts. If you need further proof, buy a factory distributor cap and compare it to a pep boys cap.
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