93 240sx that just won't run right no matter what.

[2_Liter_Turbo]

Ok here it is: I drive a 1993 s13 coupe with about 137,000 miles on it. It is a 5sp "california" car.

Stuff done:

I have removed the AIV setup. Replaced cap and rotor (Nissan OEM), wires and plugs (NGK), and EGR valve all about 25k miles ago (1 year). Replaced O2 sensor (5 months ago) with a bosch unit, replaced MAF with a used one (nothing changed so I figured they are both good (tested the second one)). New Alternator about 10k miles ago. I also replaced the PCV valve (not the seperator or hose though -stupid me-) about 10k miles ago. About 20k miles ago I re-did all the timing stuff and had all new exhaust valves put in.

Problem (ever since I bought the car):

It idles like crap. It has to be warm, but when it is idleing at Operating temperature it will sit at 650 rpms then just drop to about 50 rpms spring back up then go back down then back up and hold 650 rpms for about 30 seconds, then repeat itself. If I drive the car (it feels a bit slugish) it will drive fine untill I let off the gas then it will go down to about 50 rpms then spring back up and do the same thing it does at idle untill I hit the gas again. sometimes it will stall completely.

I've done numerous tests, but not sure what to make of the results. I have taken off the A.I.C.V. valve and tested the little pluger (moved just fine), cleaned and put back. I have done the vacuum tests on the EGR valve (it dies if vacuum is applied) and the secondary valve (no vacumm below 2k rpm, vacuum over 2k rpm). I unplugged the EGR control solenoid and it ran better while idling and when I hit the gas and let it go it went back to a high idle (about 1,200 rpm's), then I drove on it for about 10 min and it went back to running like crap. I also tested and re-adjusted the TPS sensor (it works just fine). I believe it may be the EGR Control SOlenoid or the PCV Hose and Seperator. By the way, it is throwing a code 32 (EGR FUnction).

Any imput would be greatly appreciated and I do have plenty of tools as well as a multimeter and the Factory service manuel. Thanks ahead of time for any imput.

Edit: I also get crappy gas mileage (about 17 mpg on highway) if that helps. and I replaced the fuel filter (nissan OEM) when I did the timing job.

[s13sr20chris]

try removing egr valve and cleaning it out. make sure you cant blow air through it when the plunger is down.

[2_Liter_Turbo]

I'll try that tomorrow, thanks for the reply though. Also, what is the best way to just block off the EGR setup??? I live in an area with no smog, and I have no money so I just need something that will work for now.

[2_Liter_Turbo]

Well I tested the EGR valve, and it is good. I retested the control valve for vacuum, passed again, and did the voltage test on the harnes to EGR control solenoid and the battery power test on the solenoid itself. They also passed. I looked around again for cracked hoses ect to no avail untill I check the hose that goes from the EGR control valve to the AICV valve (I think), which is quite hidden. It had a hole in it. Problem solved to a long time annoyance. I'm glad it was a simple fix! My car runs like a champ now, thank goodness.

[s13sr20chris]

great! glad it worked out.