Help! Unable to rev past 5000

[WVZR-1]

Originally Posted by GOLDCYLON

They mount next to the frame and the battery and control the Secondaries in concert with the DIS. The Quad drivers come in pairs and command 4 injectors each of the secondaries hence the name "Quad" I forget which year no longer has them but it might be 93 and up with the 405HP release.

I've never heard the term "quad driver" except from Daryl and I never knew what the he!! he was talking about. All years have the "pair" of injector drive modules, on the later cars they're mounted on the rear of the RH wheel-house on a multi relay bracket.

Clint - your '94 should be on the RH wheel-house

Quad driver failure has specific error codes when GM ECM utilizes them and they're built into GM ECM circuitry. Do these modules serve a similar function? Don't know. Now I do know what Daryl has been referring to though.

Where the terminology came from? I have no idea.

There's been many conversations regarding quad-drivers through the years and Tyler mentions ECM, it's been mentioned they were on the PROM - all sorts of silliness.

[GOLDCYLON]

Originally Posted by WVZR-1

I've never heard the term "quad driver" except from Daryl and I never knew what the he!! he was talking about. All years have the "pair" of injector drive modules, on the later cars they're mounted on the rear of the RH wheel-house on a multi relay bracket.

Clint - your '94 should be on the RH wheel-house

Quad driver failure has specific error codes when GM ECM utilizes them and they're built into GM ECM circuitry. Do these modules serve a similar function? Don't know. Now I do know what Daryl has been referring to though.

Where the terminology came from? I have no idea.

There's been many conversations regarding quad-drivers through the years and Tyler mentions ECM, it's been mentioned they were on the PROM - all sorts of silliness.

I learned this term from a few members quad was used as each module controls 4 injectors. However I posted both terms to not confuse anyone. Your right however after a little research all ZR-1s have these modules but as stated they moved. GC

[GOLDCYLON]

Originally Posted by chriskinzel

I will be changing crank sensor and fuel filter tomorrow. I don't know what to do about the quad drivers. Keep your fingers crossed!

Chris

Chris I forgot to mention a few of the Crank Position Sensors out there had a bad batch for a while. The magnet was installed backwards. When you pull the OEM unit match up the replacement unit tip to tip. If they attract the replacement unit is bad. They should repel each other if the magnet is installed correctly.

[chriskinzel]

Originally Posted by GOLDCYLON

Chris I forgot to mention a few of the Crank Position Sensors out there had a bad batch for a while. The magnet was installed backwards. When you pull the OEM unit match up the replacement unit tip to tip. If they attract the replacement unit is bad. They should repel each other if the magnet is installed correctly.

I will be sure to verify magnet orientation before anything is replaced.
Chris

[chriskinzel]

Update
Decided to drive the car to dinner tonight. The miss is now starting anywhere from 2500 to 3500 rpm. I revved it in out of gear until it started to miss. It was at 3000 rpm. Fuel preassure was 48psi. Dark smoke coming from the exhaust. Tach had about a 1000 rpm swing. This is with no load on the engine. I will still be replacing the crank sensor and fuel filter tomorrow.

Chris

[GOLDCYLON]

Originally Posted by chriskinzel

Update
Decided to drive the car to dinner tonight. The miss is now starting anywhere from 2500 to 3500 rpm. I revved it in out of gear until it started to miss. It was at 3000 rpm. Fuel preassure was 48psi. Dark smoke coming from the exhaust. Tach had about a 1000 rpm swing. This is with no load on the engine. I will still be replacing the crank sensor and fuel filter tomorrow.

Chris

Well here's my thoughts on that. I did not suspect the crank sensor because it was not having a problem until the 5k rpm range. If the crank sensor was bad it would have problems at all rpm ranges. Sounds like you could be on to something. GC

[Demps]

PROM installed correctly? Have a good ECM to compare?
Ted

[GOLDCYLON]

Originally Posted by Demps

PROM installed correctly? Have a good ECM to compare?
Ted

Yep Ted that's a possibility as well

[chriskinzel]

Originally Posted by Demps

PROM installed correctly? Have a good ECM to compare?
Ted

I think the PROM is installed right. I don't have any other ECM to compare with. I will have more results in the morning. Too hot now to mess with.

Chris

[Pete]

Originally Posted by chriskinzel

Update
Decided to drive the car to dinner tonight. The miss is now starting anywhere from 2500 to 3500 rpm. I revved it in out of gear until it started to miss. It was at 3000 rpm. Fuel preassure was 48psi. Dark smoke coming from the exhaust. Tach had about a 1000 rpm swing. This is with no load on the engine. I will still be replacing the crank sensor and fuel filter tomorrow.

Chris

Sounds like secondaries not coming on or shutting down.
Check codes.
Check secondary vacuum solenoid under plenum make sure it's pluged in.
Also make sure MAP sensor under ECM is pluged in.

When secondaries don't work it shuts her down at 3k rpm(like rev limiter)

Maybe recheck chip program sometimes the best can miss something.

Do not throw parts at it.

Pete