legacycentral bbs

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- also ignition coils have been replaced by late model WRX coils (ignitor deleted)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

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

Florin1 wrote: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

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.

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

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

Good advice to start with the basics.

Legacy777 wrote: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