High Rpm break-up

SuperStang90

SuperStang90

Club Member
just wanted a couple opinions before i tear into it.. my car has been braking up at high rpm pulls like 5k to redline. Car didnt do this last year with the exact same setup, fuel pressure set the same ect. only thing ive done so far this year is a new set of plugs. Its your basic H/C/I setup Fuel injected car. Anyone ever delt with this? It almost feels like its runnin out of fuel, but the car has a fresh 190lph fuel pump last year. and i believe the pressure is at 40psi idle. Thanks in advance
 
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Did you park the car for the winter? If so check the inside of the cap for rust or moisture. Also put a fuel pressure gage on it and drive it, that will tel you if that is the problem.

PAUL
 
sounds like plugs. Try a free rev to the rpm it breaks up at, if it breaks up you may be floatin valves. if not, id have to say its ignition
 
ignition......check wires for possiable rodent damage/ check plugs. basically check entire ignition system.
 
1BADAIR said:
is the plug gap the same as before?
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Well that might be an issue, we basically threw the plugs in out of the box without checking he gap this time. I did eyeball them all to make sure none were closed up. I drove it the other day and it seemed to be ok so idk whats up with it. I have an appointment with Alternative in a couple weeks to get it tuned, maybe thats all it needs. I still have a completely stock ignition system minus FRPP wires, but didnt think that was the issue since I ran it at the strip last year after i did all the engine work and it was fine, pulled all they way to 6k plus with no problems. Another thing i was thinking is that maybe my Electric fan is pulling to much from the coil, which is where I pulled ignition power for the fan cause i couldnt find anything else with ignition power.
 
superstang9085 said:
Well that might be an issue, we basically threw the plugs in out of the box without checking he gap this time. I did eyeball them all to make sure none were closed up. I drove it the other day and it seemed to be ok so idk whats up with it. I have an appointment with Alternative in a couple weeks to get it tuned, maybe thats all it needs. I still have a completely stock ignition system minus FRPP wires, but didnt think that was the issue since I ran it at the strip last year after i did all the engine work and it was fine, pulled all they way to 6k plus with no problems. Another thing i was thinking is that maybe my Electric fan is pulling to much from the coil, which is where I pulled ignition power for the fan cause i couldnt find anything else with ignition power.
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ign power for fan, use the coolant sensor power wire.

First thing I would do is pull the plugs and gap them all to .054, Don't just throw them on, it's a simple job.
 
;1680556 said:
ign power for fan, use the coolant sensor power wire.

First thing I would do is pull the plugs and gap them all to .054, Don't just throw them on, it's a simple job.
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yeah i know, i was in a bind at the time just trying to figure out what was wrong to get it home and didnt have a gapper, but I will pull them this weekend and verify the gaps. And i will switch that power wire, I really didnt like the idea of it there but one of my buddies insisted on it, never thought of the coolant sensor....thanks
 
superstang9085 said:
yeah i know, i was in a bind at the time just trying to figure out what was wrong to get it home and didnt have a gapper, but I will pull them this weekend and verify the gaps. And i will switch that power wire, I really didnt like the idea of it there but one of my buddies insisted on it, never thought of the coolant sensor....thanks
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you're welcome
 
i had the same problem i had 1 plug wire that was bad and only cut out at wide open i bet that is it i also changed fuel pumps first and thats how i caught it.
 
Sounds electrical to me. check the gap or replace the plugs to start out. My cutlass had the same problem under load it would buck and loose power at high rpm randomly . I got new plugs, wires and a coil pack and that solved the problem.



good luck
 
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