Bad running EJ20G, need help

[trac]

Dear all,

I've got some issues with my EJ20G engine from a 1992 Legacy Turbo.

- car is hard to start, takes some 5-10 sec. cranking before it fires up.
- when started, no smooth idle, almost sounds like running on 3 cilinders. You can see the engine rocking.
- Up to say 2500-3000 rpm, there's a vibration coming from the engine.
- when accelerating, it pulls just fine, over 3000 rpm is runs pretty okay without vibration.
- only don't get enough boost, maybe 0,5 bars (7 psi) at max.
- no codes or nothing coming from ECU.
- no major loss of coolant of engine oil.

What's been done so far (first I had primeraly a low boost issue, so focussed on the boost components then) Later the engine started running rough as descibed above):
- cleaned crank and camshaft sensors
- exchanged MAF with another (old) one
- exchanged turbo with another (old) one
- exchanged boost solenoid with another (old) one
- exchanged lambda with another (old) one
- cleaned injectors
- measured fuel pressure (@ 3 bars)
- checked MAP sensor and verified with Select Monitor it gives correct values
- checked temp. sensor and verified with Select Monitor, measures 85 C on highway use, okay. Temp meter on dash is reading correct
- also ignition coils have been replaced by late model WRX coils (ignitor deleted)

Soon I'll replace the spark plugs and do a compression test.

Does anybody have other suggestions why my car is running crap?

Thanks for your input, Bram

[Florin1]

Check your injector for ohm resistance? I had a rough idle issue as well, and it turned out to be a dead injector.

[trac]

Check your injector for ohm resistance? I had a rough idle issue as well, and it turned out to be a dead injector.

I'll do that soon, thanks for the tip.

I had two sets of injectors, and recently swapped the old set for a cleaned set.
Installing the cleaned set didn't make any difference however.

Bram

[Jessekrs123]

Definitely sounds like one or more of your spark plugs are fouled. Those are the classic symptoms.

Replace the plugs and see if it works.

[trac]

Well, thanks for the quick replies so far, but I guess I could rename this topic 'start at the basics'.
Today found some time to check out spark plugs and compression.

Anyway, see pic how spark plug of cil. no. 4 came out. Exactly, in two pieces and the electrode being rusted tells me it's been cracked some time.


Also, then the compression test:

cil. 1; 11.0 bar
cil. 2; 7,0 bar
cil. 3; 10,5 bar
cil. 4; 6,5 bar

So both my driver side cilinders below par. Not good!

There you go, I know I should have done this a long long time ago (basicly first thing I should have done), but focussed too much on my low boost values when I got the car running.
Also since I never got any ECU codes or oil / coolant consumption (also CO2 test came out fine) I kind of bypassed the basics. Good lessons learned here.

bram

[Legacy777]

I'm assuming since replacing the plug everything was alright?

Good advice to start with the basics.

[trac]

I'm assuming since replacing the plug everything was alright?

Good advice to start with the basics.

Well, I was hoping I found my problem, but looking at the compression test results indicates some more issues with this engine.
I guess having only 6 to 7 bar compression on two cilinders explains the engine vibration and the low and slow boost pressure...
A fresh fcd EJ20G with some STi/ACL/ARP goodies is awaiting install!

Bram