EGR Connecting Tube Mystery

ncgarrel · 01-04-2006, 08:18 PM

I have a 94 MGM and am having assorted problems--mainly the car barely runs when it is cold. I've troubleshot just about everything discussed in this forum.

I just noticed that on the flexible tube that connects the exhaust to the EGR valve there is a small "J" shaped tube. It looks like this tube should be connected to a hose or at least capped off.

I cannot find anything about this tube online. Do you guys have the same set up. What is or is not connected to your tube?

Thanks

cobradude360 · 01-19-2006, 03:17 PM

hey is it the tube that connects to the exhaust manifold or the smaller one because if its the smaller one its the tube that a rubber hose connects to to connect it to the dpfe scensor

ncgarrel · 01-19-2006, 03:29 PM

Yeah man it is a small tube, like maybe a 3/8 inch. that looks like a little J. What is the DPFE sensor and where is it located.

Thanks for your help. Also, I just got a shop manual and will look in it tonight.

BTW- I changed the plugs, cleaned the wires, cleaned the EGR build-up, cleaned the MAF, and Idle Air, etc. and now the car runs fine except the check engine light still comes on, but only half as much as it previosly did. So things are looking up.

cobradude360 · 01-19-2006, 09:00 PM

u prob knocked it off when cleaning the iac and stuff back there i beleave its located on that lill black plate thats behind the upper intake plenum (the curvey part of your intake that bolts to the throttle body)

gm94 · 03-26-2006, 07:11 AM

Yeah I was wondering about his tube also. It comes from the EGR valve to the exhaust pipe. I can't get my EGR Valve out because i can't even remove the tube. Any suggestions?

cobradude360 · 03-27-2006, 08:27 AM

get some rust penatrint and soak the hell out of it

gm94 · 03-27-2006, 05:12 PM

Quote:

Originally Posted by cobradude360

get some rust penatrint and soak the hell out of it

I actually had to use a short wrench and costumize it to fit the tube but i got it out. thanks for the advise. By the way nice car.

cobradude360 · 03-27-2006, 07:17 PM

why thank you and you cant complain with results im happy you got it out, why are you taking the egr off might i ask?

gm94 · 03-27-2006, 09:05 PM

Well i was having code 332 :insuficient egr flow. A friend told me that its probably the egr valve. Turns out to be that the egr orifices that come from the intake to the egr valve area were 90% blocked with carbon deposits. I cleaned it out and put everything back together, it ran like a champ, but i put the old egr valve back because it looked ok to me. I had better acceleration and power and no check engine light or codes.

Well stupid me >< decided to go back and change the egr valve for the new one.I also replaced the spark plugs with new ones. Now my car is hesitating abit in idle. Im thinking that it could be the spark plug cables since i didn't replace them. But i decided to put evrything back the way it was, so i put the old egr valve back, still no luck. I put my code scanner and it gave me code 172:" HEGO (oxygen sensor) voltage signal indicates "lean "( bank # 1 )". I notice another oxygen sensor on the driver side of the engine which i had never replaced.

I went and got the spark plug cables and the O2 sensor today. I'm going to change the cables 1st and test tomorrow. If doesn't work ill try the O2 sensor... By the way how many O2 sensor are on this car? 2 or 4 ? GM 94 4.6L. And which side is bank #1?

I learned today that if a car is running fine DON'T mess with it! LOL.

cobradude360 · 03-27-2006, 09:17 PM

well if you never replaced the plugs i would def replace them and also have you cleaned the horse shoe like passages under the intake plenum? that will cause a running problem and as for the o2's do you know how many cats you have becuse that will tell u how many o2's i have 2 on my 92, one on each exhaust manifold so hope this helps any more?'s id be happy to help you out if i can

gm94 · 03-28-2006, 01:08 PM

I have 2 O2 sensors, i did replace the other one today and the spark plug wires with no luck. Engine is still hesitating. A friend told me check the gap in the spark plugs. I'm using autolite plugs (AP464). I called the auto parts place and they told me that the gap is 54. The plugs were at 45 so i adjusted them. The hesitating got worse now. Also i think that one of the bolts that holds the egr stripped, but i was able to get a good hold of it, the other bolt grabed fine so i think that the valve is fine. But a friend mechanic told me that if there is a vaccum leak at the egr valve gasket that it could be the problem. I don't hear any air leaks so im not sure. Going to check the old plugs gap and check to see if im getting a code on the scanner... oh man what a week...

gm94 · 03-29-2006, 08:06 AM

Well LOL ill be damm... i forgot to plug one of the spark plug wires ><. I rescan the computer and no codes. I can still fell a small hesitation on the engine but not that bad. I gaped the spark plugs, that seem to help a bit. I'm wondering if i have a small vacum leak, but i don't hear anything on the engine area. Question: If i remove the vacum hose on the egr valve with engine at idle, does the engine idle changes or not? because is not. I can't fell any vacum at all from this hose at the egr valve. But if i back track it to the egr sensor,it has 2 vacum hoses to it. One coming to the sensor (in) and one that goes to the egr valve.The one coming to the sensor (in) has a strong vacum, when i plug them to the sensor and i remove the one at the egr valve i don't feel any vacum. It's like the sensor( which is a switch) is not working. It has 12v at the wire harness plug. Is the sensor working ok?

cobradude360 · 03-29-2006, 08:32 AM

i would try replaceing the egr vacum silinoid i think its called its easy to replace and should fix your problem do you have a vacum gun like a mighty vac?

gm94 · 03-29-2006, 02:08 PM

No, i don't but i can get one. I have a felling that this looks like an electrical issue. It feels exactly like when a spark plug wire is not making a good connection. Also the egr valve bolts are not stripped, they just needed a little bit more torque. Tested the computer this morning again and no codes. Going to check the gap in the old plugs just to check and i'm going to install the old plugs back. I think that if the solenoid was bad it should create an egr code. But ill check anyway. Thanks again for helping me.

gm94 · 03-29-2006, 07:12 PM

This is getting annoying... I pull out the air intake elbow, the egr valve, spark plugs and iddle controller. (again) i verified the gap for the plugs again. Checked that the plug cables are making good contact. I cleaned the idde controller with some air intake cleaner. I put a new gasket on the new egr valve. I put everything back together making sure that all bolts were tight enough. I also replaced the fuel filter.

I started my car and its even worse. Now the iddle is bad. It hesitates all the time. At night the headlights and dome lights pulsate. If i put it in gear gets even worse.

The only things that i have left to try is get a new iddle controller, throttle position sensor and the egr solenoid that you mention. I'm running out ideas. I'm very frustrated because it doesn't make any sense.

I still thing this is something electrical but i don't know what to think any more. I will have to use my last option... take it to a mechanic. LOL

Can you think of anything else?

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