The rubber intake elbow is on there well and there are no tears in it. The MAF sensor is connected properly. I'm unsure what could be causing the idle issue.

 

http://shbox.com/1/1996_evap.jpg

Do the factory service manuals contain a part number listing, or would that info be found elsewhere? I believe most of the exploded diagrams I've looked at only provide a description, and no part number. I also need hose 5 in the above diagram. I tried to describe it when placing an order, but ended up getting number 10 instead. It was only about 3 bucks, so it's not a big deal, but it would be nice to have the exact part number when ordering stuff. I'm guessing the parts numbers above would be the same on a '94?

 

It looks like the #5 hose is p/n 10105324. At least that part number seems to coordinate with hose #5. #14 looks to be p/n 12556259.

 

I took my throttle body apart today and tried some electrical cleaner on the IAC. It didn't seem to do much, and per Injuneer I steered clear of carb cleaner. Is there anything else you can use to clean it? Is it important that it be clean? Am I wrong in thinking that if you delete the EGR system, the IAC will no longer get covered in soot?

 

yes. the egr does not let exhaust gas into the manifold until after the throttle body. the iac gets dirty from the everyday air that goes in the intake track

edit: i went back and read this entire thread and there is one thing i think you should spend a little more time looking at. a vacuum leak will cause exactly what your talking about with the idle, and if you still end up having drivability issues you may want to check your exhaust for leaks before the o2s and possibly even swap the o2s with some known good units

 

I don't have any exhaust leaks before the o2 sensors. I'm leaking a little bit out of the collectors where the headers mate to the Y pipe but the o2 sensors are in front of that. The o2 sensors are just over a year old with less than 10k miles on them. They're Declo sensors and I would hope that they'd still be good. I'm not getting any codes either.

I took care of two vacuum leaks that I know were present and checked for other worn or dry rotted vacuum lines. I didn't see any.

 

You don't necessarily need factory hoses. Many auto parts stores sell the plastic hard line, and various elbows and connectors that you can piece together to replicate the factory parts.

 

Well I drove the car for a little while these last couple days and it seems that it's doing the exact same thing. It's misfiring, backfiring, and choking at idle just as it has been the whole time. I've replaced the opti, it's got brand new wires and fairly new plugs (less than 10k) I've cleaned the IAC valve, I've replaced the MAF sensor, I've fixed some vacuum leaks, and I've cursed about a million times at it. I don't know what the problem could be.

 

might want to try replacing the coil wire, thats what fixed mine

 

It's brand new and so is the coil.

 

Ok, I took out a couple spark plugs today and my dad says they look fine. They don't look fouled or anything and they're about 15k miles old (if that.)

One more piece of info to add: When I start the car after it has sat overnight or for a few hours, it runs fine for a minute or two. Once it starts coming up to temperature is when it starts running badly.

 

I'm curious, do you have a scanner? If so, watch your MAF. Do you have K&N type filters? I've seen the surge occur when the K&Ns are over-oilled (sp?) which puts a coat of oil over the MAF. This affects the reading of the MAF.

Monitor the Current Data of the MAF. Raise and lower your RPMs, the MAF should respond quickly and match the RPMs. If you do inspect the MAF for an oily film and see that it is dirty, I recommend this cleaner for your MAF.



Napa Online

 

No, I don't have a scanner but I did have it recently scanned. I do have a Moroso filter but it has been a while since it was oiled so I'm sure any overflowing oil is gone by now. I already cleaned the MAF so I know it's not dirty. When I did have it scanned, the guy said the MAF numbers looked normal.

 

Any insight into this one guys?



Second note: I'm wondering if maybe my aftermarket tune is no good. The car ran fine prior to the headers and custom tune (which were done at the same time.) After the tune and headers, I drove the car to Michigan, and while it didn't run perfectly, it wasn't horrible, but it was worse than before the headers and tune. However, in the last couple months it has been getting progressively worse.

 

Are your headers coated? I'm not really sure whether they could be causing your symptoms, but your O2 sensors could potentially be an issue if the problems only occur after the car is warmed up.