EGR malfunction

[Juglenaut]

1994 Cavy Vin 4 L4 Automatic trans throttle angle cable shift selected with vacuum engaged TCC. Flash ECM OBD-1 1/2

I know the egr is bad and have little time or money to replace it yet so I deleted and bypassed the EGR for now so it will run.

Now I am getting alot of vacuum or so it would seem it has a different vacuum curve and doesn't go into TCC after 35mph anymore. I would have to guess that the whole system is effected by the increased vacuum even the map, brake boost and what not. The engine now idles slightly higher and has a higher starting torque probabaly from the high idle. As the engine is turned off you can hear the vacuum suck through the IAC port.

Now to diminish the vacuum?? A thing I noticed at idle I was getting what seemed like pressure pulsations from the EGR intake side port, would a one way PCV buffer and breather hooked up the air intake tube help.

How would I kick down the vacuum?

Adjusting the IAC won't help this will make the vacuum higher, same with throttle angle.

[tractorman]

put the crack pipe down and walk away slowly

[Husky]

put the crack pipe down and walk away slowly

Officially nominated for "Best and Worst(simaltaneous) Reply to a troubleshooting post evah!".

[Juglenaut]

frackin newbies



I just tested it with a vacuum gauge with and without the EGR and I do frellin get more vac dim wit.

[tractorman]

That may be true dimwit, but there is no way to "diminish" the vacuum- and I doubt it'd help you anyway. You're gonna have to straigten out that EGR mess first. Hell, the ECM is probably is some sort of limp mode right now.

How do you know the vacuum is excessive? How much vacuum is the gauge showing? What does it normally show?

Depending on the condition of your engine, your altitude, and lots of other factors, I assume it's in the neighborhood of 18 inhg. Idling the engine faster will generally increase the vacuum by a couple or three inches (unless your cat is clogged- it's a common test). My guess is that IF you have more vacuum than before you took that EGR off (which is doubtful), then it's only because the engine happens to be idling higher in limp mode (or open loop... whatever the hell you kids are callin' it these days).

If you're broke: swallow your pride and guy buy an EGR at the junkyard. And make GODDAMN SURE that that EGR port isn't plugged. They're bad about that... I had to clean out the corsica's port with a coathanger.

[Juglenaut]

The gauge is showing 4 Hg increase bypassed. that is 4 inches in mercury.

This is not a digital ECM goverened EGR. Simple vacuum regulated EGR that is controlled by a EGR solenoid separate from the EGR diaphram.

The solenoid is functioning normally and buffered that so the only thing it could fault is the o2.

I know the port is clear to the valve I am not stupid.

I have a lack of both time and money, time mostly as I work 70 hours a workweek yes also as much as a doctor. I have 2 jobs plus I work weekends on odd jobs. I have a child that is 20 months and he had some intermediate medical problems but is okay now thanks for offering me crack though.

I was simply asking why no need for the rude comment and I don't care if you were joking. Now if you just relied the way you just did I would have felt differently. That phrase hit deep okay and if you want me to explain why I would hope you have a large byte limit on your e-mail.

[tractorman]

Well, bud... I can't say that I really give a rat's ass WHY your panties are in a wad. My advice is free, and you get what you pay for.

I guess it'd be helpful to know what engine we're talkin' about here. I read 1994 OBD 1.5 in your post. This IS a 60-degree V6 message board, so I'm ASSuming that you have a 3100... a '94 3100 has the digital EGR.

I HAVE been wrong before though- believe it or not.

That said, there ARE setups out there with a vacuum-diaphragm EGR that will set a code if the EGR is removed or otherwise gone bad. Some cars have a switch inline with the vacuum line that the 'puter expects to close when vacuum is applied. The previously mentioned '94 3100 can set a code even if all wiring is intact and functioning properly- if the 'puter doesn't see the vacuum change it expects when it engages the EGR, it'll set a code... and a similar logic COULD be applied to any system with the EGR actuated by a vacuum solenoid. Can't say for sure about that one- it's little more than speculation.

There isn't a vacuum leak where you blocked off the EGR port (or elsewhere) is there? That could cause the high idle.