Problems with rough idle and stalls when coming to a stop

[plainzwalker]

Even though I'm getting an SR20 in the next few day's I want try to and figure out this problem that showed up today. I've had a rough idle since I got the car, but today when I was driving the car it seemed like it was lacking power. On the way home it would stall/die when I pushed in the clutch when I was coming to a stop at a red light or traffic.

After doing some searching on here and reading some of the FSM, I decided to try check the electrical connections and see if all the plugs were good. They all seem fairly new, and in good condition, the spark plugs are in good condition and no oil on them. The ignition cables seem to be in good condition. I did find one problem, but I'm not sure what part this could be:



It's the orange/red plug in the center. One thing that I did notice since I got the car it did smell like it was running rich (unburnt gas in the exhaust). I do plan on installing a walbro fuel pump after the engine swap. Could this just be that sensor or maybe a clogged fuel filter?

Any ideas? Or should I just let it sit till it's time to drive it to the shop for the swap?

(I really want to get it running decent so I can have some more fun with the car before it gets a transplant.)

Thanks

[plainzwalker]

Sorry, forgot to include 93 240sx with a KA24de I do believe.

[plainzwalker]

K.. did some more searching and went out and tested the resistance on the fuel injectors. 3 of the 4 measured at a lil over 12ohms, while 1 was like 3.x ohms. I'm guessing that its shorted.. Could this be causing the stalling/rough idle?

Thanks

[nzmoman]

you should search really carefully again, there are a ton of aricles on rough idle and stalling problems for the KA.

Also, can you be more specific on how the car idles and how it stalls. If it is your injectors you more than likely would notice that during driving also.

[plainzwalker]

you should search really carefully again, there are a ton of aricles on rough idle and stalling problems for the KA.

Also, can you be more specific on how the car idles and how it stalls. If it is your injectors you more than likely would notice that during driving also.

K, thanks.

[plainzwalker]

Searched again (lost count after last night) and tried a few more things. So far I've tried these:

Grounding MAF = no changeDisconnecting/Reconnecting MAF = no change on disconnect, reconnect engine almost dies then comes back and idles roughEngine coolant sensor (red plug front left of engine) = replaced, and rewired connector since it fell apart when I took it off. no changeChecked all the electrical connections, and hoses.Plugs look good and fairly new, no oil or fuel smell on them.Tried resetting ECU by pulling the pos battery cable, and reconnecting after 20 mins, no change.

Only thing I have found wrong is the TPS connection was bad, fixed that. Also when testing the fuel injectors the 2nd one from the front read a low resistance (~3 ohms) while the rest read about 12 ohms.

I haven't checked the fuel filter/fuel pump. The pump will be replaced with the swap.

Symptoms: Rough idle/engine shake upon starting the car, engine runs smooth after 2500rpm, when coming to a stop with the clutch pressed in RPMs drop quickly and car stalls/dies but will restart immediately, loss of power in all gears. Almost sounds like its missing as well, I can smell gas in the exhaust as if it is running rich. Could one of the fuel injectors be bad?

[edit] Also, no engine codes are being thrown.... at least no check engine light [/edit]Any ideas? I am at the point where I'll just let it sit the next few days until I take for the swap (even though I don't want to let it sit).

Thanks

[xiongbs13]

Even though I'm getting an SR20 in the next few day's I want try to and figure out this problem that showed up today. I've had a rough idle since I got the car, but today when I was driving the car it seemed like it was lacking power. On the way home it would stall/die when I pushed in the clutch when I was coming to a stop at a red light or traffic.

After doing some searching on here and reading some of the FSM, I decided to try check the electrical connections and see if all the plugs were good. They all seem fairly new, and in good condition, the spark plugs are in good condition and no oil on them. The ignition cables seem to be in good condition. I did find one problem, but I'm not sure what part this could be:



It's the orange/red plug in the center. One thing that I did notice since I got the car it did smell like it was running rich (unburnt gas in the exhaust). I do plan on installing a walbro fuel pump after the engine swap. Could this just be that sensor or maybe a clogged fuel filter?

Any ideas? Or should I just let it sit till it's time to drive it to the shop for the swap?

(I really want to get it running decent so I can have some more fun with the car before it gets a transplant.)

Thanks

that is your tem. senser that could cause your car to not start at times and sometimes stall your car so it would be wise to change that out too

[plainzwalker]

that is your tem. senser that could cause your car to not start at times and sometimes stall your car so it would be wise to change that out too

Yah, I replaced that first actually.

Anywho, problem solved. After reading some FAQ's and posts on 240sx.org I finally found something that helped.

So for those that can't find the answer to their problems maybe you should try this first:

While engine is running, pull 1 ignition/spark cable at a time, if the engine almost dies then the injectore/cable/plug is in good shape. If nothing happens, then inspect the cable (swap with another one and test again), plug and finally injector.

Apparently measuring 3 ohms on an injector is a sign of a failed injector, wish someone would of told me that sooner instead of me trying to check everything else. After 1 1/2hrs of trying to get the injector out, and a 20 minute trip to an autozone before they closed I had the new injector installed, hoses connected and fuse replaced with a VERY smooth running car. All this just to drive it 1 or 2 more days before I get the swap done. God I love this car.

Oh yeah, if anyone else plans on replacing the Engine coolant sensor, make sure you have something to catch the coolant that comes out of the hole (oops, kinda forgot that part).

Thanks for all that helped (xiongbs13)

[nzmoman]

dude, all the things you tried just made you smarter...congrats on a successful fix

catch ya round

[plainzwalker]

dude, all the things you tried just made you smarter...congrats on a successful fix

catch ya round

yes, it did make me smarter, but there are times when after messing with something all day, and most of the night that you just need a little help. it seems like when people ask for help it's like the last thing they get. maybe im jumping to conclusions. but its fixed now, so thats all that matters.