My friend brings his 96 scooby round due to it not being able to run with the boost solenoid connected.

He bought the car, and the wastegate was connected directly to the turbo outlet (therefore bypassing the wastegate actuator).

When connected it went directly up to over 1 bar on his guage and gave the fuel cut out brick wall effect. He now has a working actuator.

He has a boost guage which reads -0.7 to -0.8 bar on idle.

Driving the car, the boost rises as in any other impreza and gets up to .7 bar and has a major misfire problem.

I done the ECU diagnostics check myself and got 11,21,31,44,45. After a few checks and parts swapping. I got my old ECU out of the shed and put it in. Hey presto, no error codes.

The car still has the misfire problem. Any ideas what to look at next?

He doesn't have any other guages to see what's happening. And due to the fact he doesn't have very much money left due to a forthcoming wedding, he can't afford to take it to a proper garage.

 

I'd put money on it having at least one cracked coilpack. These are easy to check, but are expensive to replace at £60 each for new ones. (There are 4 in total, and they are located on the plugs in the heads.) It'll probably need new plugs too.

Where in the country are you? I don't mind helping one weekend if you're not far from Southampton... I have some Deltadash style ECU diagnostic software that could help you too. (Will give quite a few useful things like AFR, ignition timing, coolant temperature etc.)

 

I have considered it being the coil packs.

However, my theory against it is that the car was rolling roaded recently running low boost. It sounded fine, but had only .4 bar boost. The car runs fine up to 7000 rpm with no stutters (with the actuator bypassed).

Would the extra boost cause it to misfire very badly, even though it was fine without it?

I do appreciate the offer of help. I've done plugs/coil packs plenty of times, so I'm quite handy with them now. I may just swap mine over to his to see if that makes a difference.

 

The coil packs need to supply more power at higher boost to ionise (spark) the higher pressure gas. If they are an their way out, you will only notice it at higher boost.

Try closing in the plug gaps to 0.5mm, if this improves things then it is defo the coils.

Andy

 

Thanks for that explaination Andy. I'll give that a try.

Also, has anyone experienced faulty ECUs giving error codes like that?

 

I also had one of those ECU's !! It would impose a 4000rpm rev limit too !!