1995 Maxima - EGR Valve not working

[NutriaforBreakfast]

Noticed the car sometimes is not running right-sounds like"chug chug" but it is an intermittant problem.

Checked the EGR valve and it was not moving while enginewas hot. I reved up the engine and couldnt feel the diaphrammoving in it. I tested the EGR valve with a Mytyvac tester and thevalve does move with it.

So I have no vacuum available to operate the EGR valve.

I changed out some worn and slightly cracked hoses and alsochanged out a solenoid ($80, EGR and canister solenoid-has a greenpatch on it with two outlet stems for the air an one inlet made withcopper and rubber). I tested the female connector and I have volt powergoing to the solenoid.

Since the car has been super, I am going to go ahead and put on thea new EGR-BPT valve (60$,next to EGR valve) and a new EGR temperature sensor ($120, close to the firewall screwed into the upper intake manifold)and new hoses. The temp sensor connector tested ok for volts.

Other checks I will make;1) Clean EGR tube from EGR valve to upper intake manifold

My question is this; Shouldnt I have vacuum to the EGR solenoid?What would cause it not to have this vacuum?Any suggestions are welcome

Thanks

[MaximA32]

The EGR guide tube is a very common problem. It gets clogged with carbons from the exhaust. The only way to solve the problem is to replace it. So what I'm saying is that you're on the right track by checking it.

[NutriaforBreakfast]

Has anyone worked on the EGR related items. I was wonderingif anyone has replaced the EGRC-BPT valve or the EGR tempsensor? Did you have to take off the upper intake manifold?

Have those little tubes under the throttle body stopped up on youbefore? How did you open them up?

[NutriaforBreakfast]

Not getting vacuum from throttle body for some reason. I wouldswear the hose to solenoid is clear and throttle body outletis clear. Gonna work on Thurs night

[NutriaforBreakfast]

Had my engineering buddy help diagnose. He believe there shouldbe some vaccuum under the EGR BPT valve but its not getting it.I ordered the steel tube running from the regular EGR valve to theEGR-BPT valve and hose ($30). I think it is carboned up.Will put on this weekend or next.

[NutriaforBreakfast]

Nothing wrong with the tube between the BPT valve andEGR valve (Part 14751/14755). I dont think the passages to EGR valve from the exhaust manifold are clogged if you can raise the EGR valve with your hand and the engine starts stalling? If the passages are cloggedI can do away with removing the EGR valve again.

Only thing I can do next is remove the plenum

color code and trace those little vacuum lines

If passages clogged:

re-clean the EGR tube (Part #14120) originally cleaned last year

reclean the EGR guide tube (Part#14713) originally cleaned last year

remove EGR valve (part #14710) and replaced last year to check forcarbon blockage behind it.

remove EGR spacer (part 14717) and check for blockage behind it

Any suggestions welcome!

[NutriaforBreakfast]

Rechecked solenoid which actuates EGR-BPT valve and emissionscanister. Went through FSM and everything on it tests out ok on it.When it has power, the correct tubes are open and closed. Same waywithout power. The ECU is also sending 12V as power to it.

Hard to tell if EGR valve is functioning or not. Reving engine to 2000-4000produces no movement but no CEL is on. Will be interested to see ifit passes TX inspection or not. They will test an old car like mine on thedyno. I noticed my car was 9 times UNDER the NOx limit. Hope they dontfeel the valve and just look at air spec.....maybe.

Tried the jumper wire thing and totally melted it when I hooked itup to the solenoid.

Will pull the plenum when it cools off around here

[turbocat]

the only thing, i can think of is to, disconnect the vacum hose to the egr valve and connect a hand held vacum pump to the nipple where the vacum hose was removed, apply vacum to the valve, the diaphragm inside the valve should open and the engine should cough and stumble badly or stall, if it does the egr valve is working, so that would confirm the egr valve is working or not working.

[turbocat]

another thing to check would be the engine coolant temp sensor, if the coolant temp sensor is telling the computer that the coolant is warm, when its really not, then the egr solenoid would supply vacum to the egr valve, if engine rpm is above 900 rpm, below 900 rpm the egr valve should be closed, and above 3200 rpm it should be closed, between 900 and 3200 rpm egr valve should be open, not 100 percent sure on the rpms, this info i got from my haynes repair manual for a 89 maxima

[turbocat]

can you hook up an obd II scanner, i know 1996 and newer is obd II, but some cars 1994 and 1995 are obd II , i have a 1998 maxima, so have a 4th gen same as your car, my mom has a 92 maxima with over 158,000 miles and still running great

[NutriaforBreakfast]

The engine does try to stall when I connect the Mytvac and applyvacuum to the EGR valve.

I replaced the EGR temperature sensor but have not checked the enginetemperature sensor. I am getting voltage to the sensor too.

I know I am getting a good reading on the engine temperature from the dash though (reads right in the middle as it always has when hot).

I first got the code PO325 and PO400 but I have cleared these codes.I put on the new parts and have not gotten other codes. I wonderif it really might be working even though when I rev up the engineI dont feel it move.

[pm_page6776]

There is a lot of info here so I have a couple of questions. I'm sorry if i missed it.1. Do you have vacuum to the EGRC solenoid? Remember that there should be ported vacuum to the valve. It will only be there if you rev the engine.2. Have you checked to see if you have exhaust pressure at the bottom of the BPT valve? If there is no exhaust pressure the BPT will not close the vacuum leak. 3. Is there vacuum out of the EGRC solenoid? ECU cuts vacuum under all but specific driving conditions. So when the vehicle is parked the ECU will be turning the solenoid "on" cutting vacuum.4. Has the running problem changed since you replaced the EGR valve? There may be another problem like a MAF sensor issue.

[TECHLINE08]

i think the ball has been drop on the issue. First off does it run rough at idle, part throttle, cruise, WOT? EGR will not open at idle, nor will it when you rev the motor with no loads.

[NutriaforBreakfast]

Car does not run rough at any time

EGR does not open as far as I can tell. I wasnt willing to rev it upover 4000 RPM to see if it would open. My engineering friend wantsto bet it works but we cant tell.

Still no check engine light yet. Inspection is in 10/09 so I will keepyou posted if it passes or not.

On my wifes 98, you can feel the EGR working with your hand with the car in park and the engine is hot.

[NutriaforBreakfast]

I PASSED! Waiting to see my NOX readings