EGR Problems

[tbirdsps]

I live in Ca. so I can't get rid of the EGR system.

Here's the problem.

200 six with C5 auto tranny in a 82 Cougar wagon:

New EGR valve that matches the underhood emissions tag. Removed all the plumbing and checked for carbon and reinstalled. Installed the EGR valve with the recommended 255 restrictors. Idles great valve is working. Measured vacuum at the valve vacuum hose is zero at idle and slowly builds to 10 at 2,000 rpm and at all times the vacuum is steady and the needle does not waver or jump around. This tells me that the PVS (ported vacuum switch) and the VCV (vacuum check valve) in the line are fine.

While driving at speeds above 35 mph there is a surge that continues through 60mph. Very annoying. This happens cold or hot.

With the EGR vacuum hose plugged the car is totally smooth when driving.

I've removed the restrictor in the inlet side and this made the problem worse so I reinstalled the restrictor.

I have not removed the valve outlet restrictor to try that yet.

I think it'll be fine for the smog inspection but I don't like driving it this way.

Any thoughts?

[tbirdsps]

No suggestions?:(

[yodaddyz82gt]

does your car "stumble" with the egr vac*** line connected? this happened to me. mine wouldnt run smoothly with it on. so i disconnected it, then plugged it like you mentioned then problem solved for me. i only use the egr system every couple years only for smog. will run like crap with it on. i dont know but thats all i can tell yuh, hope somebody else can chime in for yuh..goodluck.

[tbirdsps]

does your car "stumble" with the egr vac*** line connected? this happened to me. mine wouldnt run smoothly with it on. so i disconnected it, then plugged it like you mentioned then problem solved for me. i only use the egr system every couple years only for smog. will run like crap with it on. i dont know but thats all i can tell yuh, hope somebody else can chime in for yuh..goodluck.

Unfortunately that's where I'm at. This is a recent event so I'm confused as to what to do.

This weekend I readjusted the idle mixture at 900 rpm, rechecked the timing and adjusted the idle down to 600 in drive. The situation is much better. But there is still surging (light now). I get the smog inspection Friday. The only thing that could be iffy is the evaporative system check. It's not something I can do at home. I'm pretty sure the rest will pass.

[tbirdsps]

The problem is fixed. It wasn't an egr problem. The carb float was cracked causing a rich condition. Those dang plastic foam floats! I replaced it with a brass float and the problem is solved. The car runs like a top now.

[Dean_T]

Congrats! I didn't see that coming!

Thank you for sharing.

Dean T

[TWR2003]

The problem is fixed. It wasn't an egr problem. The carb float was cracked causing a rich condition. Those dang plastic foam floats! I replaced it with a brass float and the problem is solved. The car runs like a top now.

Glad you solved the problem. I would not have guessed a float issue considering it ran well with the vacuum hosed plugged.

FWIW - I was going to suggest if you could monitor vacuum at the EGR valve while you drove the car recognizing that engine vacuum is completely different at a given RPM depending on whether the engine is under load or just being rev'd in neutral.

T