Barely Idleing??? PLEASE HELP!!!
 

Hello,

As I was driving home yesterday my 90 GT started to feel like it wanted to stall. Sitting at a light the idle went down to 500 rps and wanted to stall. I pushed the gas and it came back to life. I managed to get home, barely but now my car idles at about 800 and sounds like it wants to stall??? I also have no power when I hit the gas? It has new sparke plugs (autolite) so I don't think this is the problem. Could it be fuel delivery? I believe this problem is also related to my car bucking at low rps, if this info helps. ANY IDEAS???

Thanks

OH, I think I need to mension that the o2 sensors that connect to the exhaust on the bottom of the car are not connected and the egr valve does not have any vacuum lines on it. I also have the ocassional high idleing problem which is cured by restarting the car. This has never caused any problems before other than a little of a rough idle sometimes. I thought this information was needed to give good advice. THanks.

From what you are saying it seems like you don't have any O2 sensors hooked up....I have to ask why? The EGR system is a must also. Get a Chilton's book and look it up yourself. They cost $15.00 and are well worth the money for the amount of info you can get out of them.

How does deleting the EGR valve effect drivbility/performance?

Not sure how it effects driveability since I've never had mine off but I do know it'll cause a check engine light to come on if you don't have it plugged in or removed. I also saw in the Chilton's book that the diagnosis for a lot of idleing/surging problems were caused by faulty EGR systems. The check engine light means that the EEC-IV isn't getting a response from that particular valve. I'm sure someone can hop in and explain what types of problems no EGR's will cause but I should of added "to pass emissions" to the previous statment I made about the EGR system being a must.

The reason why problems are caused by the egr is because of it being stuck open. Causing an internal vacum leak. Mine had a leak in the diaphram cuasing surging/barely idiling problems. I made a plate to cover it and bolted that on. The check engine light is on and my car is running better.

jpumpkinn: CHECK FOR VACUM LEAKS!!!

read this: http://forums.mustangworks.com/showt...threadid=25708

You need to leave the EVP sensor hooked up so that the computer at least thinks it has control over the EGR. If you don't, it'll run in a limp mode. YOU ABSOLUTELY HAVE TO HAVE YOUR O2 SENSORS HOOKED UP for the computer to control fuel correctly. Get that fixed right away. Make sure you plug the vacuum line that was going to the EGR valve.

can I unscrew the egr sensor from the back of the EGR valve and leave it plugged into the harness?

The problem with that is that the sensor might be giving an open all the time reading for which the computer will compensate. The best thing would be to install a plate between the EGR and EGR spacer and then disconnect the vacuum. You may also be able to come up with a way to jumper the connector to make the computer think the EGR is closed all the time and remove the valve, sensor and EGR spacer. I plan to do that somehow so that my C&L air tube fits better. I'll fill everyone in on the way to do it when I figure it out.

This looks like a good fix: http://www.ronmorrisperformance.com/05spec/

I've got a 95 302 in my '65 and obviously didn't want to mess with emissions controls. On mine, I have left the EGR in place, the EVP is connected like normal, and the vacuum line and solinoid that operate the EGR is functional. I have capped the 'inlet' into the EGR, where exhaust would normally enter. The computer thinks the EGR is functioning properly, which it is, but it's not actually doing anything.

Now, in terms of drivability, it really doesn't impact performance (positively or negatively). The only purpose of the EGR is to introduce small amounts of exhaust gasses back into the intake in order to ensure everything is burned. It only does this during part throttle and just off idle. It does not allow exhaust to re-enter the intake during WOT or during cold start up. the only way it could impact performance is if it is sticking open.

There is no performance reason to remove your EGR system, but if you do, leave the solinoid, EVP and EGR in place. This will ensure you don't get any MILs.

ONE of the reasons i am removing it is becuase there is a small hole in the diaphram and its causing a major vacum leak. So I coudn't leave it on.

I agree, first thing you should do is get those O2 sensors hooked back up. It sounds like it is a fuel delivery problem, so you might want to make sure your injectors are not clogged. Have you tried flooring the car? Does it loose power after you push the pedal down more than 25%? If so, you may want to check for a bad mass air meter. Let me know what happens.

Jason

I agree. Your O2 sensors must be hooked up. There is no way around it. Even the guys who convert their 60's Stangs to EFI need O2 sensors. Every vehicle with a Electronicaly controlled Conputer system needs O2 sensors. The O2 sensors send a signal back to the CPU which tells the CPU to adjust air/fuel ratio to the optimum 13.7/1 ratio. This ratio is considered a perfect condition (or as close to perfect as you can get). Without the O2 sensors you are running either very lean or very rich. Evidence of this should be seen on your plugs.