EGR system is tickin me off

[k20]

Ok all, Ive had a random problem of when I get on the interstate and cruise my check engine light comes on, and its the EGR system. Doesnt happen everytime I get on the interstate, but it never comes on in town, and only happens if I cruise at a constant speed for awhile (read: it doesnt come on during the morning rush hour). However after a few nights of driving on the interstate with this glowing orange light Ive had enough. I change the EGR with another I had, and changed the MAP sensor with another I had, and checked the vac lines. No problems. This is seriously pissing me off. Any ideas?


BTW, this is on the truck below in my sig, its the stock 87 tbi computer running the edelbrock mpfi conversion setup.

 

[jekquistk5]

I had the same problem, but I replaced the EGR Soloniod and that fixed it!

 

[1979jimmy350]

your rgr could be sticking open because of carbon being blown in to it with all the rpms. This happens to me evey time i go between school and home all i have to do is take the valve out and clean out the carbon

 

[dyeager535]

I'd second checking the solenoid. On the early EFI systems I believe the computer tests EGR function by enabling it at cruise periodically, and if there is no change in the O2 reading, it will set a code. Thats probably a VERY basic explanation of what it does, but I don't believe your system can monitor EGR temp, so the only way for the system to know is to watch the O2 sensor as EGR is commanded on.

Not sure what the test is though, sorry. Probably fairly simple, can probably watch EGR commands through a scanner, but won't tell you if the solenoid is actually working. ALDL log probably would though.

 

[k20]

im retarded, all i know is the EGR valve (round lookin thing on the manifold) and the MAP sensor(2 vac ports, and has the little round filter). I had an extra of each, and neither solved my problem. WHere is the EGR control solenoid? Thanks.

 

[dyeager535]

On the TPI stuff it is mounted on a bracket with the coil. Two wires running to it, two hard vacuum lines (one to EGR one to vacuum source) and a small square foam filter.

 

[k20]

http://www.partsamerica.com/product_images/AAP/GPS/VS-VZ/VS4.jpgDoes it look like that? If so I had a spare one and that didnt fix the problem.

 

[dyeager535]

MINE doesn't look like that, but its stock, so who knows?

It looks like a similar idea though.

 

[jekquistk5]

http://www.partsamerica.com/product_images/AAP/GPS/VS-VZ/VS4.jpgDoes it look like that? If so I had a spare one and that didnt fix the problem.

Something like that!!!
Id test the Valve as well, Let it warm up then press the valve in and if the engine chokes or stalls its doing what its supposed to!

 

[k20]

well i got inspection well, tomorow, and thats my last sniffer....If itll pass, Can I then just put a blockoff plate on the egr, and then do something with wiring and vac lines to make it think its allgood?

 

[dyeager535]

Like I said, I believe there is a routine the ECM uses to check EGR, either through knock or O2, so I don't believe there is any way to trick it.

http://dyeager535.topcities.com/TPI/ First page, picture "coil mount". EGR solenoid is the black thing right above the coil, I just didn't have the vacuum lines run yet, but you can see one of the broken off ones there.

 

[k20]

yeh I dont think I have anything that looks like that. Im gonna see if I can get my friend to let me borrow his laptop & aldl cable and log it this weekend, see whats up.