4500RPM Redline

[Erik123456789]

I have a boosted OBD1 f23 with a crome tuned p28.. and one day I randomly got a redline at exactly 4500RPM.
The way it happens is if I'm easy on the gas pedal, the car will slowly pass through the 4500RPM mark, but if I gas it hard then the car will abruptly cut off at exactly 4500RPM.

I tried fixing it by replacing the distributor, spark plugs, and a different ECU (using MY chip) but the redline still won't go away..

Any ideas on what I should try next??

 

[Drift]

Any Cels?

 

[pattywak]

This may not be relevant because the same thing happens on my friends jetski on high boost, but maybe it's fuel cut? I'm not sure if it would work the same way for land vehicles. lol.

 

[Erik123456789]

Any Cels?

I have OBD1 now, the scanner plug doesn't work anymore and the only person who could check thrown CEL codes is my tuner but that isn't free lol.

 

[Erik123456789]

This may not be relevant because the same thing happens on my friends jetski on high boost, but maybe it's fuel cut? I'm not sure if it would work the same way for land vehicles. lol.

Oh yeah I think it might be a fuel cut.. but I don't understand how this happened, do you think it's possible that my fuel pump is going bad?

A few days ago I was driving and my car randomly shut off and it wouldn't turn on anymore. The symptoms were exactly the same as when you run out of gas. The only thing I could do that day was wait.. and so I did.. and after around 10 minutes my car turned back on and ran fine again.

This hasn't happened again YET, so I'm not sure if it's the same problem.. but I remember in one of our old cars the fuel pump would stop working after the car was driven for a while and the only way to ever turn it back on was to let the fuel pump cool down a bit. This wasn't random though, this happened every time the car was used and wasn't fixed until we actually replaced the fuel pump.

Well anyway.. fuel cuts occur when the ECU senses more air than fuel right?

Well then.. if my fuel pump were to start going bad.. then it wouldn't be able to supply the engine with the same amount of fuel it got tuned for.

At low bost it works fine, but past 4500rpm and much higher boost is when the fuel pump REALLY gets over-worked.

So the only thing the fuel pump can do is give out.. and as its giving out, the ECU performs a fuel cut to "save" the engine from further damage??

 

[Drift]

I have OBD1 now, the scanner plug doesn't work anymore and the only person who could check thrown CEL codes is my tuner but that isn't free lol.

You can check the code yourself. Is the CEL hooked up to the dash still?

You can use the same paper clip trick in the OBDII port to start flash codes.

 

[Erik123456789]

You can check the code yourself. Is the CEL hooked up to the dash still?

You can use the same paper clip trick in the OBDII port to start flash codes.

Haha I tried doing the code check thing you told me about but my CEL insert thing doesn't even have a light bulb!! Should I just use a lightbulb off another thing and put it in the CEL insert to check the light blinks? or are they different.

 

[boneyS]

I have a boosted OBD1 f23 with a crome tuned p28.. and one day I randomly got a redline at exactly 4500RPM.
The way it happens is if I'm easy on the gas pedal, the car will slowly pass through the 4500RPM mark, but if I gas it hard then the car will abruptly cut off at exactly 4500RPM.

I tried fixing it by replacing the distributor, spark plugs, and a different ECU (using MY chip) but the redline still won't go away..

Any ideas on what I should try next??

the same thing happened to my car a while back but i notice i had a bit of a gas leak by the regulator .....i fixed it an now its runs like a dream again so.... check for leaks

 

[Erik123456789]

the same thing happened to my car a while back but i notice i had a bit of a gas leak by the regulator .....i fixed it an now its runs like a dream again so.... check for leaks

Ohhh I see, I'll be sure to try that next. Thanks!

 

[studweiser83]

I have a boosted OBD1 f23 with a crome tuned p28.. and one day I randomly got a redline at exactly 4500RPM.
The way it happens is if I'm easy on the gas pedal, the car will slowly pass through the 4500RPM mark, but if I gas it hard then the car will abruptly cut off at exactly 4500RPM.

I tried fixing it by replacing the distributor, spark plugs, and a different ECU (using MY chip) but the redline still won't go away..

Any ideas on what I should try next??

I had the same thing happen to me on the highway a few weeks back. I checked the CEL code and got a VTEC error. I had to replace the VTEC solenoid that was leaking oil.

The cause of the problem turned out to be that my oil was low and the ECU engaged a "safe mode" which set a rev limiter at 4500 RPM's to prevent the motor from doing any serious damage to itself while it's low on oil.

Not being able to check your codes puts you in a tight spot. Check your oil if you haven't already and look for oil leaks. Until you figure out the problem, my advice to you is to drive your car as little as possible. That is unless you want to replace the whole motor.