egr problem

[logicisall]

I have a 91 Metro LSI 3 cyl 5 speed. From CA, so has that EGR system.
Getting code 51 on ECM, which is EGR. Went thru Factory Manual trouble shooting:
ECM is providing correct voltage to solonoid.
Solonoid controls vacume with 12v.
Modulator appears to work with pressure
EGR moves with vacume.

One place in manual says solonoid should be 120ohm, mine is 300ohm, which is what another place says it should be.

Check Engine only comes on after fairly long drive, and sets the 51 code again. Any ideas what to check? I am in AZ, and really don't need the extra CA emissions stuff, but would not want to damage the engine by just blocking it off.

Doesn't the EGR introduce exhaust gas to cool the mixture under heavy load?

[geozukigti]

yeah, i burnt up a 3cyl engine head in 2 weeks by blocking off the EGR on it. Try spraying some de-carb up in the egr valve, and in the lines that go through the head. It could be all plugged up with carbon, and giving false readings to the ecu.

[logicisall]

Originally Posted by geozukigti

yeah, i burnt up a 3cyl engine head in 2 weeks by blocking off the EGR on it. Try spraying some de-carb up in the egr valve, and in the lines that go through the head. It could be all plugged up with carbon, and giving false readings to the ecu.

You were 100% right! I removed the EGR, and the 2 large ports had some carbon buildup, about 50% plugged, but the middle size tube was 100% plugged. Scraped them out, and now I get flow, and no more Check Engine light (at least so far). Thanks for the info.
dMb
Logic is all

[geozukigti]

anytime