1990 240SX, DE swap, rough idle - EGR?

[90de4u]

I bought a 1990 240SX with the DE swap not too long ago and there is one problem with it. When I go to start it in the morning, it will die so I have to give it gas for about 15 seconds or so, so the choke will catch and then it will idle roughly around 1,000rpm.Also, when I am driving and then push in the clutch, the idle is erratic...it will be as low as 800 sometimes. Usually stays right around 1,000 though. When I am slowing down in neutral, it will be as high as 1,500 - 2,000 and stay like that until I hit the gas a bit and then it knocks it back down to 1,000rpm.

I was told when I bought it that the EGR valve needed to be replaced...I am not sure if that would cause the car to do this or what. It drives just fine...has a lot of torque, acceleration is spot on. Doesn't have any ignition misses. I am wondering if the valve is just stuck open or what the deal is? It does have a CEL but nobody has an OBD1 scanner to read the code.

Mods done to the car:

KA24DE swapCone filter adapted to the stock intake tube and MAF sensor2.5" exhaust with resonator onlyStage 2 Exedy clutch

[DALAZ_68]

if its the EGR id say just rip the damn thing out and block it off

if u can get ur hands or better yet search this site for the codes do the code search straight from the ecu and let us know what the code/s are

[90de4u]

How would I block it off?

Also, I thought maybe it could be the sparkplugs or wires...so I turned the car on and pulled one plug at a time to see if the idle got any worse. It didn't get much worse than it already is.

I put in some Engine Restore, to see if it has anything to do with compression. I don't have the equipment to do a compression test right now.

I might take the EGR off and clean it tomorrow. Not sure what's up with the car....don't really want to pay a diagnostic fee...like I said, it's only at idle, which is weird.

[DALAZ_68]

How would I block it off?

Also, I thought maybe it could be the sparkplugs or wires...so I turned the car on and pulled one plug at a time to see if the idle got any worse. It didn't get much worse than it already is.

I put in some Engine Restore, to see if it has anything to do with compression. I don't have the equipment to do a compression test right now.

I might take the EGR off and clean it tomorrow. Not sure what's up with the car....don't really want to pay a diagnostic fee...like I said, it's only at idle, which is weird.

basically u put a steel plate over the the whole where the EGR tub connect...

i did it by removing the WHOLE assembly and putting in a V shaped looking plate with new cut out gasket...

if its ur idle...could be ur IACV or TPS

[90de4u]

Not sure what it is. Had a hard time getting the EGR tube off (didn't get it off actually) and I couldn't get to the second 12mm bolt holding the EGR onto the intake manifold.

Found a vacuum hose that goes from the EGR to BPT that had a huge hole in it....replaced that but nothing happened. Not sure what's up with it. I'm going to just take it to a shop and have them figure out what's wrong with it. Will save me the hassle....will have to be fixed one way or another.

What would cause it to not start up when the engine is cold, and me having to give it gas? And only be weird at idle but not when I'm driving? All the power is there...not sluggish. Great low and top end torque. Not sure what's up with it.

[dickie]

if you need a blockoff plate i have one for sale.

[90de4u]

I will end up removing it most likely....is there a writeup on what exactly to do? Because the EGR itself is a ***** to get off, and I can't undo that tube or the 12mm bolt behind the intake manifold. I'd rather not take the manifold off. How much are you selling that plate for?

[dickie]

i paid 11.00 + shipping like 2 weeks ago. i will send it to you for $10.00 + shipping

[DALAZ_68]

if ur tryin to take it off the valve...its a *****

if u take off the whole assembly...much easier 3 bolts and over...thats excluding the nut on the exaust...which BTW ur gonna have to get closed off aswell...just take it to the shop cut the pip and tell then to weld the crap shut

[90de4u]

OK, so I take off the tube from the exhaust manifold.Then remove the three bolts behind the EGR itself.Do I also remove the other small piece connected to the top of the intake manifold? I think it's the BPT...?

This won't throw any CEL codes?? Also, do I use the same bolts for the EGR to put in that plate?

[dickie]

yes, you will need a new gasket or (unconfirmed) im told that high-temp rtv works.

[90de4u]

Whoa, this is kind of dumb...found the problem. There is a vacuum hose under the throttle body. I got to looking around and saw that there is a nipple on the stock intake tube that has a vacuum cap on it and I heard a tiny sucking noise when the engine was on. Looked down near the throttle body and saw a hose that wasn't going to anything. I put my finger over it and the idle went up....took my finger off and it started to sputter like usual. Strange how one vacuum hose will prevent you from starting your car and give you strange idling problems.

So I went inside and grabbed a screw and put it in the hose. Bought different sized vacuum caps, but had to go to work....so that will be my task tomorrow. Cap off some vacuum lines.

Only problem now is that the idle is at about 1,800rpm. I am not sure if that is because of the way I plugged the hose or what. The guy I bought it from did mention he tried to mess with the idle before, but I have no idea how to adjust the idle at all. Any comments on that?

Also....which vacuum lines can I safely cap off? I don't think all of them are necessary but I could be wrong.