Emission problem...240SX stalls while idling...maybe bad EGR??

[amolao]

Here is the situation: While doing a change of oil, I broke the connection that goes to the bottom of the EGR solenoid control valve, thats where the car will run find until I stop and then stalls on me. I ran the car for a couple of days with the broken line until I pull the FSm and start tracking the problem. I never got to run a diagnostic with the computer, but while doing a visual inspection I noticed the line hanging loose (to the bottom of EGR control solenoid) I reconnected the line, and the problem is still there...Questions: Will the EGR solenoid control valve go bad when is ran without the bottom connection??? (this goes or comes from the PR/SCV solenoids).

Any other sensor that might go bad while running the car like this??/

I checked the BPT and blew on it and check for leaks and the spring is activating under acceleration....seems good..

what should I do? replace BPT and EGR solenoid and take the chance??I also check the spark plug for fouling and they are clean ..... I also checked all vacuum lines for leaks and they are good.

This is a 1989 240SX ...please help me I start a new job Monday and need to get the car going......thanks and sorry about the long post...
Modified by amolao at 5:56 AM 11/26/2005

[Magnes]

Q1: No.Q2: No.Q3: Check codes, and check for anything else that you may have broken when you changed the oil.Q4: No.

Does it stall only when you come to a stop, or anytime you let it idle down? If you start it again does it run fine until the next time?

[s13sr20chris]

ditto, you can always pull egr valve off and block it off to test.

[amolao]

Found the problem, but thanks for the assistance. I will answer your questions and post my solution for the sake of future searches.....The car was stalling at all times when I let the idle down. I will start the car again and it was doing the same...I started checking all vacuum lines, I found a post during a search from somebody that wrote: "To have vacuum you gotta have timing" , this guy is my hero, because based on that and if it works viceversa I found the line between BTP valve and EGR control had a big hole (very hard to detect the way is routed). Well replaced the line and the car started running like it was out of time, It was ...since my last timing chain job I was never able to set the car to the correct timing. That was the reason, the bad vacuum line...I set the timing correctly and the car runs top performance...like never before. I hope this helps somebody...and again thanks...

[s13sr20chris]

great, just want to throw in one thing though.

the bpt hose from bpt to egr valve is not a vacuum hose. it carries exhaust backpressure. that hose being torn will not cause a rough running engine. glad you worked out the timing thing though.

[amolao]

Mmmm...interesting... good to know, thanks for the feedback....

[Magnes]

I'm not sure he's clearly indicated which hose it is that he replaced. To me it sounded like the vacuum hose between the BPT valve and EGR control solenoid. Either way, it still wouldn't help his idle problem so it might have been some other hose entirely.

The timing problem is relevant though, like you said.

[amolao]

I replaced the hose that feeds from the bottom of the BPT valve into the EGR control valve......yeah it wasnt until I read the timing=vacumm relationship that everything clicked and I adjusted the timing to specs and the cars purrs like a kitten now......the hose from the EGR solenoid was disconected by my clumsy fingers and put back in place, thats how the problem started....