EGR Valve??

[rsmithdrift]

Alright I'm wondering what effect a malfunctioning EGR valve would have on the way a car runs.

My cars been running like crap and I checked everything and the only prob. I could find was a hole in the hose going from the lower EGR to the upper EGR (with red arrow pointing to it.)

I decided to just leave off the upper EGR (circled in yellow) and block off the vacumn line.

My question is, would that hole in that hose have been causing my cars severe running issues, and would removing that upper part of the EGR just make the egr not work anymore having no effect on the way it runs or would it make the car run poorly if at all?

[rsmithdrift]

Well to answer my own question.... No. It did not fix my problem. I got a new hose for the EGR valve and reatached everything and the only thing I noticed was that it seemed to fix my stalling after hard throttle problem.

But it still cuts out over 1/2 throttle and acts like it's running out of gas all the time. So IDK.

[scottydog]

I had a crapped out EGR system and it still ran pretty good, just kept lighting up the CEL and wouldn't pass smog.

Have you checked obvious things like plugs, wires, cleaned the throttle body/maf etc? Any error codes?

[erdrift]

So yeah i agree with the above. Check the MAF sensor. if your getting bad air readings then your gas ratio will be wrong to. My 240 would bog a lot. I cleaned out the MAF and that along with new spark plugs did the job. If you clean your MAF you can use a Q-tip to do it be careful to not mess up the wire in the middle it's brittle. I heard you can use break cleaner but don't take my word for it. Do some research on that one. Good luck.

[jetroy240]

Common problem is the egr port gallery plugged w/ carbon deposits, engine hesitates during acceleration, the ports on each intake manifoldrunner is accesible by removing the plugs w/ allen wrench & poked the hole. CEL will come on if egr system is inoperative.

I would check the distributor probably soaked w/ oil. Check ur exhaust probably restricted cat. There are many possibilities for bad misfiring, could be electrical or mechanical.
Modified by jetroy240 at 10:07 AM 1/19/2009

[rsmithdrift]

I have 3 different air flow meters. All within the 1.2-1.4 volt range at idle. All run exactly the same.

No error codes.

[locoluna825]

the hole in the old hose do you remmebr what did it look like was it a tear or did look like it was eating away, or did it look like it was worn down by something rubbing on it?

[locoluna825]

So yeah i agree with the above. Check the MAF sensor. if your getting bad air readings then your gas ratio will be wrong to. My 240 would bog a lot. I cleaned out the MAF and that along with new spark plugs did the job. If you clean your MAF you can use a Q-tip to do it be careful to not mess up the wire in the middle it's brittle. I heard you can use break cleaner but don't take my word for it. Do some research on that one. Good luck.

Oh and one more thing DO NOT clean your maf with a Qtip or anything else that physicly touches it the little wire in it is very sensitive ive broken mine only clean your MAFs with arisol cleaner.

[rsmithdrift]

the hole in the old hose do you remmebr what did it look like was it a tear or did look like it was eating away, or did it look like it was worn down by something rubbing on it?

The hole was right at the bend where the red arrow is pointing in the pic and was big enough for a pencil to fit through and looked like it had been on fire on the inside at some point. Full of charchoal.

[locoluna825]

You said it was running crappy what exactly did you mean when you said that like while driving it or during idle?

So it was full of carbon, judging on the location of that hose if some of that carbon got up inside your bpt valve it may have jacked up the diaphram in it.

I had egr issues with my car and I had to go through the process of checking almoest every component on the car but the uasully form what i have read the bpt valve and egr vavles are mos tof the time the culprits.

So heres what I would do. A vaccum test on the bpt valve and the egr valve, wich is pretty easy. you need to get a couple more sections of vaccum hose about 1ft and half each. Then you need to apply vaccum (suck on it like a straw) on the botom hose off the bbt valve (Put the longer section of hose on there the one thats has the red arrow on it) and see if it will hold vacuum, if you listen you can hear it open up it will make a quiet but distinct noise. When you do this, wait a couple seconds to see if closes back up while still holding the vaccum. If it does hold a vaccum, pintch off the hose as you are sucking on it to keep the diaghram open. Make sure its open. (I did this by putting one finger in my mouth while applying vaccum to the hose and plugging the end of it with my finger to keep the vaccum in the hose.) Now see the two hoses on the top of the bpt valve, unplug them both and put a longer section of hose(if you need to) on one of the ends. While still holding the the vacuum with your finger on the bottom of the valve blow into one of the ends on the top see if air will pass through. when there is no vacuum on the botom of the valve no air should pass through the valve, and when there is vacuum air should be able to pass through.

To check the egr valve is pretty easy just apply vaccum to the top hose in the picutre and see if you can get it to open up, this will take more vaccum than the other one so suck on it pretty hard lol. Youll deffinitly here this one open up. and see if that holds a vaccum. If it does all is well with the diaghram. Then plug everythign back the way it was turn the car on and youll need to do a little feelin aroudn with the egr valve (dont wait till it get so hot youll burn yourself) see the top of the egr valve looks kinda like a space ship you need to reach under it with 1 or 2 fingers and press up on it. and force it to oepn up If you have done this and felt it puch up the engine should start idling very crappy now or even die. If id does then the egr valve is working fine.

[Vegascorbin]

Not to thread jack but most national auto parts stores sell MAF cleaner for less than $10.00 can and plenty for more than one cleaning.

Brake cleaner can be a bit harsh on sensitive parts let alone the paint you drip it on.

[rsmithdrift]

You said it was running crappy what exactly did you mean when you said that like while driving it or during idle?

So it was full of carbon, judging on the location of that hose if some of that carbon got up inside your bpt valve it may have jacked up the diaphram in it.

I had egr issues with my car and I had to go through the process of checking almoest every component on the car but the uasully form what i have read the bpt valve and egr vavles are mos tof the time the culprits.

So heres what I would do. A vaccum test on the bpt valve and the egr valve, wich is pretty easy. you need to get a couple more sections of vaccum hose about 1ft and half each. Then you need to apply vaccum (suck on it like a straw) on the botom hose off the bbt valve (Put the longer section of hose on there the one thats has the red arrow on it) and see if it will hold vacuum, if you listen you can hear it open up it will make a quiet but distinct noise. When you do this, wait a couple seconds to see if closes back up while still holding the vaccum. If it does hold a vaccum, pintch off the hose as you are sucking on it to keep the diaghram open. Make sure its open. (I did this by putting one finger in my mouth while applying vaccum to the hose and plugging the end of it with my finger to keep the vaccum in the hose.) Now see the two hoses on the top of the bpt valve, unplug them both and put a longer section of hose(if you need to) on one of the ends. While still holding the the vacuum with your finger on the bottom of the valve blow into one of the ends on the top see if air will pass through. when there is no vacuum on the botom of the valve no air should pass through the valve, and when there is vacuum air should be able to pass through.

To check the egr valve is pretty easy just apply vaccum to the top hose in the picutre and see if you can get it to open up, this will take more vaccum than the other one so suck on it pretty hard lol. Youll deffinitly here this one open up. and see if that holds a vaccum. If it does all is well with the diaghram. Then plug everythign back the way it was turn the car on and youll need to do a little feelin aroudn with the egr valve (dont wait till it get so hot youll burn yourself) see the top of the egr valve looks kinda like a space ship you need to reach under it with 1 or 2 fingers and press up on it. and force it to oepn up If you have done this and felt it puch up the engine should start idling very crappy now or even die. If id does then the egr valve is working fine.

By running crappy, I mean it idle's fine, but if you give it more than 1/4 throttle the engine bogs/cuts out and will actually loose rpm. And it hesitates when you first touch the throttle for a second.

If you just floor it from an idle it'll bounce around misfiring at about 1200-1800 rpms. It won't go any higher. It sounds horrible.

If you ease into the throttle and get the revs up to about 4,000rpm then floor it it'll either hover at that rpm or drop down to 1200-1800rpm. misfiring horribly randomly on all 4 cylinders.

When you let off the throttle from wide open it backfires and it sounds like a gunshot. The revs actually jump up at the same time for a second and then it returns to a normal idle.

I've tested the MAF, the CTS, the TPS, the ignition system, the O2 sensor, the fuel pump, the fuel filter, the air filter, the vacumn system. All in perfect running order. Voltages are in correct range, ohms are in correct range, no codes from computer. The car seems perfect, it just doesn't run right. I had a Nissan Z speciallist hook it to a computer and he said it's running beyond 125% on the fuel mixture (extremely lean) and doesn't know how it runs at all. The only way I can "override" this problem and make the car run is by putting on a known BAD MAF that reads 10v at idle (should be 1.2v) and it overcompensates the lean-ness by a mile and it idles rough, blows black smoke and gets 14mpg at best with that MAF installed. When the car was running properly it wouldn't run with that MAF at all.

It's been too cold lately to try your test of the EGR Valve, but I do know that if you push the diaphram up with the car idling it stalls out quickly.

[speedracermage]

im sorry this is twice i did that yesterday. i have a 89 coupe body and a 92 sr20

[gdbyyosh1to]

Have you tried simple things such as checking distributor wires? Or maybe running some seafoam through the engine?

Make sure you have no vacuum leaks anywhere. Check all the lines for blockage or cracks, replace the ones that do. Or clean or repair them.

It sounds like all you need to do is run some seafoam through the engine though. It's cheap and it should probably be done anyway.

[JOEW921]

this is just a random thought but have you checked you tps i mean if thats jacked up dude and reading the wrong values then yea it could cause similiar symptoms