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jy116
07-07-2005, 06:58 PM
Got EGR System probs code on my 1991 ECU. CEL goes on sometimes, but when plugged to a diagnostics computer, it shows that theres something wrong with the EGR System.

I refered to the OEM FSM and found nothing, Chiltons manual says to manually pump the EGR valve, but the valve is enclosed. 2nd test is to take off the line from EGR to the intake box and should hear a stumble/rough idle. I did that and nothing happened... meaning the EGR valve is always open for some reason...

Any ideas? Can it be solved by cleaning something or using some cleaning products?

Thanks for any help :wavey:
sLip techniques
07-07-2005, 07:58 PM
To check if the egr is working just put your hand underneath (while the car is on) and press up, if the car bogs and idle fluctuates, its working properly. Then you should check the vacuum lines you have going from the egr the bpt valve are not cracked or have holes. You should just goto autzone and get like 2-3 feet of vacuum hose and start replacing all the hoses you see.
jy116
07-07-2005, 10:00 PM
do you have a SOHC KA? Mine is DOHC, and the bottom of the EGR valve is not accessible. I will check the hoses though, didnt think of that...
sLip techniques
07-07-2005, 10:51 PM
yeah i have an sohc, but even on a dual there should be some way of pressing up the diaphram
Indolent
07-07-2005, 10:56 PM
i have a 91, lol you could press up against it
jy116
07-08-2005, 04:48 AM
o, dint notice that... BUT WAIT... pressing up means opening the valve rite? That allows exhaust gas to flow into the intake, causing lean mixture, causing engine stumble/rough idle indicating a functioning EGR system. [since the valve should only open under intake vacuum].

BUT, when i unplugged the hose from the EGR to the airbox, NOTHING happened [no change in idle] meaning the engine has always been running lean... and I guess it has compensated? I do get pretty bad milage... avg 19 or so... still gonna chek the hoses tmro tho... i want decent mielage! and no CEL!
sLip techniques
07-08-2005, 05:17 AM
which one are you talking about that connects to the airbox??
jy116
07-11-2005, 04:16 AM
yup, hose from egr to airbox has no effect when pulled