Missing and Stalling at idle.I've Spent 2,000$+trying to fix. Its Cursed HELP!
 

Ok so here is the deal-
After spending thousands of dollars trying to fix my SR i really need some advice on what my problem could be, I am completely out of Money, so i need to get this thing running myself.


Rundown, I'll keep it brief-
-Motor is stock redtop sr, car is 93 240sx
-Motor has never run correctly after swap
-Like the post says, Motor seems to miss-fire at idle (mechanic says its running very rich),
-In the higher RPM's, car runs smoothly, but also lacks power.
-After a drive, it will stall at idle, but then start up and and idle again (still misfires)

What has been done- (if you think its something i checked, ill check it again)
-No codes on ECU
-replaced TPS (bad)
-replaced MAF (bad)
-replaced injectors
-replaced ecu
-replaced coolant temp sensor
-replaced spark plugs (ngk iridium)
-checked for boost leaks
-checked for vaccum leaks
-checked vaccum hoses (correct hookup locations)
-checked timing
-checked grounds
-checked power and grounds on ecu plug
-checked Greddy Bov (closed all the way)
-checked turbo (for runout/ missing teeth)
-checked compression (150psi x4)
I have been to two shops, both can't figure it out, One shop hooked up a power fc and got it running pretty well like that. (should i just consider going this wrought)

The only other thing i could think of is the harness, but i dont really want throw any more money down the drain.
I will take any Ideas at all! http://images.nicoclub.com/forums/im...s/confused.gif http://images.nicoclub.com/forums/im...s/confused.gif http://images.nicoclub.com/forums/im...s/confused.gif

If the Power FC ran the car well, I don't think it's the harness. Maybe the ECU has a bad tune or something. Are there any indications that the ECU may have been modified?

You checked how good the spark is? Could be a bad igniter chip...or going bad.

Also, spark plugs...what are they exactly and whats the gap?

before a replaced my bad water pump..id clutch in, and the car would idle so low it would die..replaceing the waterpump and belts fixed it right up..it was a KADE , n/a setup..but your issue sounds similar

i don't really know anything about sr20's, but have you checked things like fuel filter, fuel pressure regulator, pcv, iacv, coil(s) (the sr's c.o.p. isn't it?), ect.
have you done a fuel system test or a vacuum test? i see you said checked for vacuum leaks, but not sure if that was just looking around for disconnected hoses or if you meant actually hooking up a vacuum gauge to the car and doing a test.
did you check fuel pressure, fuel pressure leak down, voltage at the fuel pump, ect?

But why would it run well with the Power FC hooked up??? Does the Power FC fix all the problems? I don't think so.

Have you tried swapping another SR ECU into it? If droppin in the PFC made it run good then i would lean toward your ECU being bad.

I had a similar issue once, My ECU came unbolted from the chassis and it ran rich and misfired. I replaced the plugs No change, but as soon as i grounded the ECU back to the chassis it ran fine again.

P.S. Its spelled GReddy;)

Have you checked the ignition timing? sounds like you might be off a tooth. A friend of mine had the same problem with his.

Ok, i have been working on this problem day and night, in finally able to take a break and use the computer.

-fliprayzin240sx, i got around to replacing that ignitor chip, but it still runs the same

-Silverstreek, those are some very good ideas, i checked the Fuel pressure regulator, but i did not check voltage at the fuelpump reason being, the car ran fine with the ka. As far as vaccum leaks, in not really sure what was done, the shop did that one.

-Hawaiian240, you hit it on the nose, the shop i brought it to said that they got it running good with the power FC, but when i herd it in person the thing still sounded like CRAP!

-Sileighty_85, GREDDY!, ya i know lol i spelled it wrong. the ecu is fine, the shop swapped in a stock working ecu and it still did the same thing.

-Ghost05, i will check the timing chain tomorrow

Thankyou for all your responeses

As well as what was mentioned above, i have also...

-checked ignitor
-checked coil packs
-checked coil pack harness
-pulled apart entire engine harness, traced backed every wire and checked with ohm meter (all good)
-had power fc tuned, it does not fix problems.
-re-checked maf
-checked fuel pressure regulator

I had the same problem with my sr when i swapped it in. I checked the timing chain again and again, because in my mind it was a timing problem. Took me about two months of seriously knowing my whole car in and out. Bottom line is that it was because my CAS wasnt on correctly and it wasnt the timing chain.
Hope that helps.

*****update******

Ok, i got some free time so i decided to try some more things on my 240.
-replaced fuel pump (walbro)
-replaced injectors (440's)
-installed Power FC D-Jetro still nothing!

this car is a pain in the ass!!!!!!

well, like i said, a shop checked it out. they also said that they set the timing. maybe they missed somthing?

You know when you wire in a SR20DET the check engine light does not work, you need to add a wire to get the MIL light to work.

There where no codes on the ECU, so even if it had i MIL it would not be on.

just to give you guys a better update on whats going on with the car, here is an up to date list on what i have done so far...

-No codes on ECU
-replaced TPS (bad)
-replaced MAF (bad)
-replaced injectors (370's)
-replaced ecu
-replaced coolant temp sensor
-replaced spark plugs (ngk iridium)
-replaced fuel pump (walbro)
-replaced injectors (440's)
-checked for boost leaks
-checked for vaccum leaks
-checked wiring harness (pulled apart, looked good, but did not replace)
-checked vaccum hoses (correct hookup locations)
-checked timing
-checked grounds
-checked alternator
-checkes fuel pressure regulator
-checked timing chain (just top two timing marks, not bottom)
-checked power and grounds on ecu plug
-checked Greedy Bov (closed all the way)
-checked turbo (for runout/ missing teeth)
-checked compression (150psi x4)
-re-checked ecu (good)
-re-checked maf (good)
-checked coil packs
-checked coil pack harness
-checked ignitor
-checked to make sure all cylinders are fireing
-checked to make sure all cylinders getting fuel
-installed and tuned Apex-i Power FC L-jetro
-installed Power FC D-Jetro (no more maf)

**here are the symptoms i still have**

-lopey idle (very very rough, whole car shakes, it actually broke one of my new autometer gages)
-missing at idle
-low boost 5psi max
-low vacuum
-almost stalls after revving
-lack of power

and here is a strange fact, when i checked for boost leaks, there where no leaks in the piping, but alot of air did come out of PCV. (the T fitting in the valve cover)

Have you checked your altenator? i have had problems like this with my car and it seems to be something with the altenator... have it tested just a suggestion

the shop said that they checked it, and i dont really have any battery issues. how do i check it? I cant take it off and bring it somewhere because the bolt in the tensioner bolt is really rusted on, and i dont want to go through a ton of work to pull the thing off if it is not whats doing it. cant i just start the car, pull the battery out while its running, and use a volt meter to check the output voltage of the battery? I think it should be like 14 volts of somthing like that.right?

you've spent two grand having a mechanic poke at your engine?
your parents must hate you :(

well the only think i could think of is its gonna be Mechanical Timing you said you checked the Cams but not the crank

Maybe look into pulling the from cover off and checking the all three dots.

Did you check the CAM sensor?

I was told that if the cam angle sensor was bad the car wouldn't even run.

not always the case. if its on its way out it can cause misfires, runing rough and whatever else symptoms from the timing being off. test with a known working one

CAS will still work when bad. i recommend you replace it and im pretty sure that will fix you up. ive installed a few swaps that had a simular problem and swapped out the CAS and problem fixxed. email me if you have any questions i will be happy to help.

Are you guys serious? Will it also make it hard to time a vehicle? I have the messed up idle and the occasional stalling after after stopping. I did get a code 11 once but after a reset it never came back.

In my situation, the cams were off.

dude, that is soo crazy, i actually took the cap of my cas yesterday and the wheel was bent!!! I tried to bend it back, but it seems like it actually got worse, im buying a used cas as soon as i can find one, and i am also replacing the wiring harness, i will update you all soon!

does anyone know where a good place to find one is, i really dont want to shell out 300$ for a new one, and i dont have any friends withs srs that would let me barrow one.

well man i had the same problem and it eneded up being a soldering on the sr wiring harness that got loose check my thread
#/f/s-chassis/238640-sr-swap-wont-go-over-2000rpm.html

if you grab a new one, at least you know it'll work and won;t be a expensive peice of used...

have you done a cylinder leakage test, and are you sure the timing chain isnt off one tooth. what did they fo with the pwer fc to get it to run better(as fas as tune)

im betting on the CAS... still dont know why the standalone worked fine.

Just wondersing but did you get no codes or code 55? If you got nothing then something is up wih the ecu, Code 55 means no faults.

But i am betting that it is the CAS.

Solder in a consult cable to your ecu, grab a snapon Mt2500 set it to generic vehicle, and look at what's going on