Rough idel and dying

Hello all, having a problem w/ my eclipse, just bought the car about a month ago, it started off that after it was up to temp, every so often it would die when I would let the rpms drop from above 2k or higher. Well it's gone from that to most of the time when I let them drop, and now it dosn't idel well, when at temp. rpm's drop and it stalls. I brought the car into a local dealer and they hooked it up to all there fancy machines, and told me"Your car has been modified so much we don't get any errors and it would be really expensive to work on it" but, they didn't charge me for looking at it, so that was nice. but I still have a car running like crap, and I don't know where to start. any ideas would be nice. Oh, it has a chopped air box, no cat, K&N air filter, and air/fuel and boost gages. (stand back from the crazy mods)

wow...chopped air box?? get at least a filter replacement ( cone filter ) check your ignition / plugs wirings, check for faulty spark plugs. better yet...get a tune up service.

Does it idle at all without gas? If it does pull spark plug wires 1 at a time to see if it does anything to it (Leave 3 plugged in at all times) the one that doesn't change sound at all is probably the problem one LOL. When was the last time you changed plugs, wires, distributor cap, and rotor? Also the fuel filter is another one to check if it's idling bad it may be getting restricted flow until you hit the gas and force the pump into high gear.

no that sounds like a boost\VAC leak to me. Make sure your BOV is recirc still first and check your IC pipes makes sure there is no leak in air leaking out of your pipein. Other than thaty I agree with trying your plugs and wires

And as far as them saying your car has been modded to much that is Bull, they just wanted your car outta there. I had a 2000 GS with a turbo on it and an SAFC everything else needed to run a turbo and the dealer took my car in and found what my cars idle problem was. and in my case it was a VAC leak at the intake manifold so that is why I say make sure you have no leaks first

Yeah I agree the dealer was givin you a line of BS you don't have mods for SHYT that would stop them from finding the problem. Check your gauge lines for the boost gage if it's aftermarket THAT might be your boost leak... I was at first thinking idle air control motor but it won't usually die when the IAC goes bad just hunt alot.

ok, wife is gona kill me now, I was in the garage looking at the car. pulling plug wires and such, they seem to work ok, I think there might be a leak in one of the hoses comming out of the turbo. (don't know what it's called) any ways, I was reving it from in the engine bay, and all of a sudden there coolent leaking from the back area of the moter!!!! looking at all of the hoses, Im starting to wonder if it might be a good idea to bring it in somewhere and have all new hoses(coolent/vacume) put on. This is getting very frusterating. My wife dosn't want me spending alot of money on the car, (baby on the way) but I would like to get it running good, so I can start doing some bolt on type stuff.(about my level of working) is anyone in minnesota, around the Twin Citys area, that knows these cars that might be able to look/help a bit?

K coolant out the BACK of the engine sounds like a freeze plug. Easy fix but you'll need a pick set and a set of needle nose pliers and prolly a flathead screwdriver to get it out. Then take the old one to Advanced ot Auto Zone they sell RUBBER ones DON'T get the metal one that is stock it's a PAIN in the @$$ to put back in. The rubber one you put it in and thighten it with a ratchet. You'll have to do some testing and figure out EXACTLY where the vacuum/boost leak is and replace that hose.

if you have a leak it may be as simple as tightening the IC hose. BTW the hose\pipe going from the turbo to the intercooler is called the Lower IC(intercooler) pipe and the one going from the intercooler to the throttle body is called the upper IC pipe

ok, all hoses checked, no leaks. I adjusted the BISS and my rpm's are up some, about 900-950 helped a little w/ it killing at intersections. any other ideas?

Did you check where your gauges go into the turbo lines? Also have you checked the fuel filter lately?

try checking all your sensors

just picked it up from a local shop, they said I had a bad o2 sensor..... $300 later I picked up the car, seemed fine, drove home, and it started killing again!!!!!!!!!!!! another thig that they said which I didn't know, was that the engine swap that the previous owner did, they didn't put in a stock 1990 GSX engine, havn't found out what it is yet, anyone know how to tell what engine it is? And any other ideas whats causing it to die?

Does the motor have any numbers stamped on the top to at least tell what size it is?

yeah, it's a 2.0 has a turbo on the side :)

If the dealership replaced an o2 sensor exaust then they must have had an idea about what engin it was. maybe you could go back and ask what they thought it is if they noticed it wasnt a stock engin. Also there is a plate riveted somewhere on the front of the engin that tells what block it is.

yeah, they said they knew, but I forgot to ask, then the guy working on it was gone before I thought to ask. any other ideas about it stalling, they said the IACV is good, no vacuum/boost leaks. new o2 sensor...........

I know you said the dealer checked for leaks and found none. I also rember that you said you had new family addition on the way. Been there 4 times! Here is a way to check for leaks your self.

How to build an Intercooler Pipe Pressure Leak Tester
Parts Needed:

A 4 inch long piece of 2.5" O.D. (outside diameter) hose. (I used some radiator hose I got at NAPA)
1.5" I.D. (inside diameter) PVC end cap.
2 band clamps that will fit around the 2.5" pipe above.
A valve stem (I used the rubber type you press in)

Note that if you have a larger turbo, the sizes of the end cap and hose may need to be larger in order to fit the turbo inlet.

To see what it looks like go here Leak Tester.


To get the valve stem in, I had to drill a hole in the PVC cap.


To use it, just remove the intake pipe from your turbocharger inlet, and attach this in its' place.

Now you need to hook something up to the valve stem to pressurize the intake so you can listen for leaks. I use a 7 gallon air tank I got from Walmart, I just fill it up with air at the local gas station. You can also use a simple bike pump.

If you have a manual boost controller hooked up, you might want to plug off its' intake hose, as they leak a lot of air, making it hard to pinpoint the real leak.

Pressurize the system, and listen all over for leaks. Make sure you or a friend listens under the bumper too, wherever there is IC piping.

A leak will be obvious, they make a loud hissing sound.

You might want to have a friend check out your boost gauge while you are pressurizing things, to make sure you don't put too much pressure on things. (20 psi should be safe, or whatever you run safely for boost)

Places I have heard of leaks occuring:

BOV flange
Intake manifold ports
Throttle Body gaskets
Holes in the intercooler
Holes in the intercooler piping (sometimes the rubber pipe inside the stock woven mesh pipes cracks, and you can't see it from the outside... the pressure tester will find it though!! )

Pictures and Text by Brent Cook

Idea for tester from Josh Wingell

Contact bacook@mediaone.net for questions.

found one big leak, fixed it, but still having the same problem, ordered a Idle Speed Stabalizer today, I'll wait to see if that helps, keep you posted.

Cool. How and where did you find the leak? What was leaking?

Fill us in with the gory details.

Is it still dying at an idle or has that gotten better? I didn't think a boost leak would actually cause it to die... I can see a rough idle from a boost leak but would that cause it to die as well?

Still the same, my Idle speed stabalizer is going to be here in about a week. The leak was on the 90 deg. elbow of the upper intercooler pipe. It seems like I keep finding leaks on everything now, coolent leak(s), power steering leak, no oil leaks though.

LOL I know the feeling. I have an '84 truck that leaks everything but oil as well. Parked it on a cement slab and all the coolant dripped out the gearbox for the power steering is empty and even the exhaust leaks LOL.

hmmmm.....replace all the hose's lolz....

Yeah with all aluminum hoses LOL.

Idle speed stabalizer installed, idles better now. Now I'm working on my belt eating problem... I'm on the 3rd belt in 2.5 months. (Alternator/Powerstearing) had it in at a locar shop and they said my alternator work, but the bushings for the mounts are bad. It looks like an almost new alternator, anyone know if you can buy the bushings anywhere? And....they also said I need a new powersteering rack???????? ouch, any aftermarket, better parts to buy for that one, or just stick to stock?