Car trouble could use some help!!!

[TAmos827]

Ok after replacing everything that deals with the cooling system including head gasket, I finally got my cooling problem under control. Now on to a new problem.

Car info: 1990 240sx KA24(E) automatic

My problem that I am having is with high idle and hesitation or sputering. I been driving it for a while and seafoamed it and it calmed down a little and even cleaned some sensors. I noticed that in the morning since its kind cold when I first start it that it will run almost prefect no sputering or hesitating no high idle but when it warms up then it sputers a bit its only when I am easing on the gas to speed that it seems to do it but if I open the throttle a good bit to speed then it seems to be fine. Also after its warmed up and its in park getting ready to get out the car it idles around 1200 to 1500. Also if the weather is kind warm and the motor is able to warm up faster it will still sputer or hesitates apon accleration and if i start the car even after being in the store for a while and get in the car i will idle around 1200 to 1500. When its in gear it Idles like normal. I changed the temp sensors both of them and the tps senso and the IACV screw is all the way in and wont idle down anymore. Timing is correct (trust me i messed with it for two days) its got new plugs not NGK though. havent changed the cap and rotor yet but it dont have much wear. and its got new wires. I even got some MAF cleaner and cleaned it. When it sputers it acts like it doesn't have any power.

I've done my searchs and what nots and still can't seem to find an answer.

[Steve Lloyd]

as far as the sputtering and warming up issues, you might be starting to get a clogged catalytic converter. This just recently happened to me, check your exhaust flow at the tailpipe. Have someone slowly rev the motor while you feel for exhaust coming out of the muffler.

[TAmos827]

as far as the sputtering and warming up issues, you might be starting to get a clogged catalytic converter. This just recently happened to me, check your exhaust flow at the tailpipe. Have someone slowly rev the motor while you feel for exhaust coming out of the muffler.

Just bought a brand new Cat and it even did it when I had my test pipe on.Thanks though.

[nifares240]

check your vacuum lines.

[TAmos827]

Vaccum lines are good I checked all those and replaced the one that runs the flaps on the inside of the lower manifold. I plan on removing most of my emission system this weekend since I got my egr block of plate in.

[fast_s13]

check to make sure you dont have a vac leak....check the intake manifold

[TAmos827]

check to make sure you dont have a vac leak....check the intake manifold

Already checked for leaks, Could a bad MAF sensor be doing it. anyone.

[ca18detgabby]

the spuddering on the light throttle..........

sounds like a definate dirty maf. would be my first start.

I would also replace my plugs(plugs with carbon build up and/or old will cause a spudder)

for the idle....... sounds like the TB spring is either not recoiling all the way and not closing. they wear out over time.... it happens. let the engine fire up and manual recoil it all the way and see where it idles....

could also be your throttle cable has been set to idle there.... but the prior is more likely.

[TAmos827]

the spuddering on the light throttle..........

sounds like a definate dirty maf. would be my first start.

I would also replace my plugs(plugs with carbon build up and/or old will cause a spudder)

for the idle....... sounds like the TB spring is either not recoiling all the way and not closing. they wear out over time.... it happens. let the engine fire up and manual recoil it all the way and see where it idles....

could also be your throttle cable has been set to idle there.... but the prior is more likely.

I cleaned the MAF sensor and it has new plugs in it already, also the spring on the TB is still good it slams closed and thats with the TB cable off.

[ddgsxr504]

Replace your coolant temp sensor. It's on the intake manifold.

[TAmos827]

Replace your coolant temp sensor. It's on the intake manifold.

already replaced both of them!

[GoinTopless240]

I'm guessing you did the obvious - changed the fuel filter, but what about the fuel pump sock. I had a similar problem with hesitation when mine was an auto. It's an easy check. First - go to the dealer and get a rubber O-ring that goes to the fuel pump access opening (I think it's about $10, but only available from Nissan). Go to AutoZone and get a Fuel pump sock/filter (like $20). Open trunk/hatch, pull the fuel pump out. The sock is located on the bottom of the pump and can be just pulled off with some pliers. Put the new sock on and put it all back together. Mine gunked up from my car sitting for some time in garage. It would take it some time to act up when driving. I guessed the pump was getting weak from trying to suck against all the rust that was in the sock. I ended up changing my pump to a Walbro 255 cause I knew I was going SR anyway. Just a thought. Many people forget there is a filter back there. On a different note. Have you put a volt meter on the TPS and made sure it was adjusted correctly? I'd have to check the service manual for the correct voltage, but I'm sure someone here knows it off their head. I'll see if I can scan the pages this weekend for ya, unless you have an FSM already. Let me know. I actually have one for the KA24E motor (89').

[TAmos827]

I'm guessing you did the obvious - changed the fuel filter, but what about the fuel pump sock. I had a similar problem with hesitation when mine was an auto. It's an easy check. First - go to the dealer and get a rubber O-ring that goes to the fuel pump access opening (I think it's about $10, but only available from Nissan). Go to AutoZone and get a Fuel pump sock/filter (like $20). Open trunk/hatch, pull the fuel pump out. The sock is located on the bottom of the pump and can be just pulled off with some pliers. Put the new sock on and put it all back together. Mine gunked up from my car sitting for some time in garage. It would take it some time to act up when driving. I guessed the pump was getting weak from trying to suck against all the rust that was in the sock. I ended up changing my pump to a Walbro 255 cause I knew I was going SR anyway. Just a thought. Many people forget there is a filter back there. On a different note. Have you put a volt meter on the TPS and made sure it was adjusted correctly? I'd have to check the service manual for the correct voltage, but I'm sure someone here knows it off their head. I'll see if I can scan the pages this weekend for ya, unless you have an FSM already. Let me know. I actually have one for the KA24E motor (89').

FSM? Is that Fuel system manager. If its that no I don't have one already. I haven't changed the sock yet in the tank but I can give that a try. and I think I will try to get a new cap and rotor and see if that helps. Yeah I already changed the fuel filter and it helped a little. Maybe I need to do the same get a walbro 255 and use it so it will be one less thing when I get my SR20.

[TAmos827]

Bump

[iandrew89]

fsm is factory service manual i cant really think of anything else to check besides what has been said

[GoinTopless240]

Sorry.. yes Factory Service Manual.. curious if you got anywhere with it..

[diablodude64]

Hey I know it sounds to simple but I had an 89 240 that had what sounds like a similar problem but it only happend under load if I tried to give the car gas.... Anyways I changed the spark plugs and it ran awesome.