EGR

[mpullen66]

Is there any way to check an EGR Valve?  About 3 months ago my truck seemed to have a miss about 1000-1400 rpm. I changed the EGR Valve and it fixed the problem. It started doin it again. Wouldnt think its bad again???





87, 5.7tbi,700r4,2wd

[bake74]

     Take if off and check to see if 1 - there is not an excessive amount of carbon build up.  (If there is on a 3 month old EGR valve there is a different problem), 2 - check that the spring assy is moving freely and not getting stuck open or closed when you move it (no sticky points).
     Also of note, you need to check the cavity where it mounts for carbon build up, and the tubes that are hooked up to the EGR valve, most people do not check these and can be a source of plugs or excessive restrictions.
     It almost sounds to me like you have a restriction in the cavity or tube, when you changed the EGR valve it solved the problem for a short time, but now the new EGR valve has worn some and the original problem is over coming the new EGR valve.
     Hopes this helps.

[mpullen66]

I pulled the acumen hose off the egr and it stopped the problem. Can I leave it off?  It Will be w few days before I have time to look at it. Will it hurt gas mileage or any thing else?  Also,  do i need it since I have headers?  Thanks for the help.

[jaredts]

It might be nice to fix it, but you'll be okay without it.  You may have to retard your timing if you notice pinging though.  If you're at stock timing now I doubt you'll have to worry about it.

[TexasRed]

your timing may be a little too advanced now, especially the part the vacuum can gives you. If you don't have a need for it (smog check and the like), you could probably recurve your timing and be okay without it. Some gas mileage will be lost, but not much. EGR is to keep combustion temps down to lower NOx but there's an added benefit of a little more timing tolerance and mileage at cruise.

jaredts beat me to it.

[bake74]

your timing may be a little too advanced now, especially the part the vacuum can gives you. If you don't have a need for it (smog check and the like), you could probably recurve your timing and be okay without it. Some gas mileage will be lost, but not much. EGR is to keep combustion temps down to lower NOx but there's an added benefit of a little more timing tolerance and mileage at cruise.

     What he said.   

[ralphhemi]

Hi the way i clean the  EGR  exhaust port is remove the EGR valve and start the engine and throttle it a couple of times.

[Skunksmash]

I think you can verify if an EGR valve is working just by hooking up known vacuum to the right vacuum port on it. Get a vacuum source that you KNOW is working properly, and then you can tell whether or not the EGR is functioning when you hook it up to the proper vacuum port.

[VileZambonie]

Your EGR solenoid is the problem not the EGR valve. Replace the solenoid.

[mpullen66]

I was thinking solenoid also Vile. Just haven't had time to check it. Thanks for everyones help.

[mpullen66]

Changed the solenoid. Didn't help.

[VileZambonie]

So the truck runs poorly until you pull the vacuum hose off of the EGR valve correct? And you replaced the EGR solenoid, the hoses are crrectly routed?

Key on engine running with a test light verify B+ and B- are present at the EGR solenoid connector

[jaredts]

Excuse me if I don't recall correctly, but don't you need to rev. the engine to 1800 rpm or more and be at operating temp. to get the signal at the solenoid?

[VileZambonie]

Correct, it shouldn't be on at all with no load on the engine so if his solenoid is energized then either the ECM is bad or the wire going to the solenoid at cavity B is shorted to ground. Cavity A should have B+ as well as cavity B while backprobing or unplugged Cavity B with a test light to B+ should not illuminate. At this point if he has flow because the solenoid is energized he needs to find out why.

[mpullen66]

I have 14 volts on the pink and black wire and 0 volts on the grey wire. That's with engine warm and at idle and the solenoid unplugged.