I have a 90 vert that I rebuilt. The engine runs fine and can be reved to over 8000 rpms with out a load. But when I am driving the car it will not go above 6000 rpms. I had the infectors cleaned and tested before I put them back into the car durning the rebuild. So I do not think that the injectors are the problem. I really want the additional 2000 rpms back.

 

I had the same exact problem with my vert. Never solved it since i just took apart the engine to turbo it, but I saw a few things that could have caused it. First off, the plastic piece which directs the flow of the injectors was put on in the wrong direction. Another thing I noticed was that there was a restriction in the exhaust. I tried using an safc to see if tuning was the problem, but it never solved it. Up to around 5k it would rev normally and then the power would just drop off drastically.

 

Did you check your aux ports?

 

also replace the fuel filter if you havnt already.

 

1. do all the aux ports WORK? VDI? most are stuck shut... no vdi = no power after 5k

2. since its a new engine, is the cas in right? timing?

3. any codes? check it

4. cat/exhaust could be plugged, but it would have been plugged before the motor...