Wont rev above 5000rpm

[leper421]

My 91 5spd has had a problem with going above 5000rpm for a while now. What happens is the engine starts shaking, and the rpms will fluctuate between 4800-5200. This happens in neutral and in all the gears (havent gotting that fast in 5th, though). If I let the car get that high while driving, the engine puts out little to no power.

I've done a full tune-up recently, so I know its not caused by any of those items. My guess is either the fuel pump cant supply enough fuel, or that the fuel pressure regulator is crapping out. I dont have a fuel pressure gauge yet, so I cant check to see if I'm right.

[PabloHoney]

I am guessing that your first two assumptions are correct about the fuel. If that doesn't work, try this. 240's have a 5th gear rev limiter at 5100 or so. It is a pretty violent shake that happens when it hits too. So..... maybe the 5th gear sensor in your transmission is stuck on. My suggestion: try unplugging the 5th gear sensor on your transmission and see if it still happens.

[Silvia007]

my 91 auto does that... never figured out why.... sorry.

[leper421]

240's have a 5th gear rev limiter at 5100 or so. It is a pretty violent shake that happens when it hits too. So..... maybe the 5th gear sensor in your transmission is stuck on. My suggestion: try unplugging the 5th gear sensor on your transmission and see if it still happens.

You dont know how Happy I am.

The 5th gear switch was my problem. My "red line" just increased by almost 2000 rpm

My car drove fine in all gears with no 5th sensor, is it only there for the rev-limiter? Is there any reason I should replace it, and not just leave it disconnected?

[MaineExport]

You dont know how Happy I am.

The 5th gear switch was my problem. My "red line" just increased by almost 2000 rpm

My car drove fine in all gears with no 5th sensor, is it only there for the rev-limiter? Is there any reason I should replace it, and not just leave it disconnected?

I believe it is just there as sort of a back-up to the speed governor. You should be able to run without it. Good job Pablo....

[PabloHoney]

I would just leave it unplugged...it doesn't do anything besides monitor gearing for the secondary governor (sp?) Don't waste your money on a pointless sensor. Glad I could help.