D8UGF

Gents, will try to describe whats happening as best I can then wondered if you can give any thoughts or pointers as to what it might be.

Car is currently beahving like two different vehicles: below 3000rpm it behaves perfectly normally, idles fine full throttle from low revs right up to 3000rpm it accelerates very smoothly with no jerkiness. Above 3000rpm it is a completely different story.... cant put any more than 1/4 throttle down or it hesitates very badly, no jerkiness or "kangaroo" effect just a very definate missfire through all cylinders. If it is kept below the 1/4 throttle it will continue to increase it speed up to 80 in a slow build up.

This has just started today, but recently when the car is cold,on start up it will not start and the radiator fan comes on ??? after a few tries it will start eventually and will run normally.

No check engine lights or warning lights coming on.

Car is a MY94 WRX with scoobysport downpipe, Hks green mush ind kit, dump valve(not sure make) and scooby ecu.

Thanks in advance

Dougie

D8UGF

Also meant to add, only seems to do it when load is applied to the engine, while car is sitting it will rev freely up to 6k with no missfire, only when out on the road does the rough running appear

D8UGF

Bugg3r wont start now! Am I right in saying that the fuel pump should whirr when it primes on turning on the ignition? should it also whirr after engine has turned over but not fired up?
There is no noise from it at all so I'm beginning to think it may be the fuel pump or fuel pump relay(hopefully).

Dougie

The_Judge

You say the radiator fans come on when it was stone cold? That normally points at engine coolant temperature sensor malfunction. The ECU has no idea what temperature the engine's running at, so it turns the rad fans on as a precaution.

You also say you're not getting a CEL fault? Are you certain the CEL lamp works OK? Might sound like a daft question, but there have been instances on here where bulbs have gone, or even been removed... Try connecting the black connectors beneath the steering column, and turn the ignition on (not engine) just to be on the safe side.

D8UGF

Judge, thanks for your reply. Went out and plugged the black connectors as you said and it turns out that the cel is working after all. Holly **** it was like a xmas tree!

Is there any way I can decipher what the combinations are? got the following cycle as best I can make out:

3 Slow 1 Quick
4 Slow 5 Quick
2 Slow 1 Quick
2 Slow 4 Quick

As for the rad fan, it only comes on when the car fails to start, doesnt do it at no temp when running, could it be a low voltage problem? p1ssin in the wind a bit here!

Cheers

Dougie

stevem2k

31 Throttle position sensor
45 Pressure Sensor Duty Solenoid
21 Coolant temp sensor
24 Air control valve

http://www.troublecodes.net/Subaru/

D8UGF

Cheers for that Steve,

Any of the above cause the problem running I described? Think the next step is to check the fuel pump as well as I am positive it should make a noise when it is primed?

Dougie

stevem2k

I would suggest you clean your earth points before much else. They could well be pretty cruddy by now.

Steve

D8UGF

Thanks Steve, I was thinking along those lines myself, seems as tho' there are a few gremlins appearing and they generally point toward electrical problems. Might even consider doing the earth mod that everyone was doing a while ago.
Will it be ok to clear the cel codes now and just keep a note of them?

Sorry for the late replies....dreaded nightshift at the mo

Cheers

Dougie