Ok...who's the mechanic here?

[Gerald Pierce]

93 Mustang w/2.3L 4cyl. Did spark plugs yesterday. Used cheap plugs (1st mistake) and didnt change the wires (2nd mistake). Idles like crap when in gear once warmed up (idle speed slows down). So, I go get new wires and new bosch platinum plugs. All installed. Car still idles like crap. Drives good once above 15 mph. Listening, I can hear like a vacuum leak at the EGR valve (I guess that is what it is--pipe from exhaust manifold to this unit and it is bolted to the intake. Has an electrical connection and a vacuum hose). I can see what looks to be a diaphram going in and out with the idle "pulsing". Any ideas here? Should I hear a vacuum sound at the egr? Check engine light is not on. I am at a loss.... what sucks is car ran good untill I decided to do this. This is one of these freak cars with 2 plugs per cylinder.......

 

[Chops]

Since it ran fine prior, I suspect it's sucking air.

You have 13 year old rubber, hence just taking vaccuum lines off (if there is dry rot) could destroy the seal when you reconnect.

Re-examine ALL vaccuum lines for placement, and cracks.

 

[shawn stonbraker 2]

The EGR works off vacuum. If the diagphram is moving then it should be fine. The problem with those is when they get stuck. The way you test them is by pushing on the diagphram and making sure it moves. (at least that's what they tought me in GM school) What does the distributer cap look like? (does it have one or is it electronic?) (not sure about Stangs) I would concentrate on the ignition since that was when the problem started.

 

[EddieS'04]

the diaphram on the EGR should not be pulsing at idle...either the EGR is bad or the sensor that cotrols it is bad...if you can see the diaphram, put a piece of tubing on it and suck on it to make it move..block it with your tongue and wait to see if it bleeds down..if so the diaphram is bad...you might have to buy the whole valve...



Ive done this test, it works...

 

[stgry1 chris]

To be honest..drop the platinum plugs. If the car didn't come with it as OEM parts, don't add them! You can actually be losing performance from those plugs just for longevity. But since they are in, I doubt that is causing the problem (unless they are not gapped properly--never trust a pre-set gap in the box). Take off and clean the IAC valve and TB with quality TB cleaner. Reset ECM/PCM. We used to also have huge problems the FPRs on that motor but you aren't experiencing those symptoms exactly. Good luck and keep us posted.

 

[Gerald Pierce]

I assume cleaning the IAC is just like doing the ST's.... I will try that tomorrow and also the EGR. I could not get a good seal on the vacuum line for the EGR, so I trimmed the end off and now it seals tight.



Also, it ran good after changing all the plugs at first.... drove 20 miles down the road and stopped. When I restarted, thats when the problems began.



Thanks for the tips, if anyone thinks of anything else, let me know.

 

[shawn stonbraker 2]

Water in gas?

 

[Tom Schindler]

I agree with stgry1. Too many times I have seen people put Bosch Platinum plugs in a car and have it run like crap. Ford built the engine. They make a darn nice plug. Use it.



Bad idle usually means you habe a problem with the ISC valve. I would, as other said, check the vacuum lines. A propane torch will usually let you know if there is a vacuum leak.



An EGR system should not cause idle problems. it is used to cool the combustion chamber by adding inert gas into the engine. A car will run fine without an EGR system hooked up. Since the Mustang is older then 1996, it is not OBD-II compliant. So the EEC-IV computer is a little more forgiving.





Tom

 

[Gerald Pierce]

Water in gas?

I hope not, but could be. I only get gas at name brand stations, but I did just fill up (now to remember which one). It ran good after I filled up though, and runs good now except for the idle issue...... I guess the only way to know is to drain the tank or run some dry gas through and change the filter.



Tom, Thanks for the info.... I will check the ISC today (if it stops raining.)