1993 ka24de AT hesitate when drive, die on idle

[SamuraiCJ]

Hi all,

My 93 240sx AT is giving me a headache again.

A month ago an injector went out so it was replaced along with spark plugs and cap and rotor. I felt that the fuel pump is going out soon because sometimes i dont hear it priming when i turn on the car and when it's cold or parked on a downhill slope, it is hard to start the car.

this past weekend i replaced the O2 sensor. I took it on a 5 miles of local driving and a 35 miles of freeway driving it was nice and smooth.

Here comes the problem this morning. When i started the car, the idle seems to be weak since the rpm is only about 400. When driving it, it seems to choke or hesitate under 2500rpm. At a stop sign, the rpm jumps back and forth between 100-700 rpm. And it even dies. So i have to keep on gasing it a bit to keep it alive and do left foot braking so i can drive to school.

I kind of scan through some google results and people think the causes could be the fuel pump, spark plug wires, maf, or the egr.

Any idea guys?

[S13ZX]

this was my problem this week........my car was hesitant to start....so i disconnected the maf and tried to turn on the car with the timing advanced all the way so that it can stay on....wen i reved it....it would not go past 2500 excactly.....i went to the junk yard to see if i could find a good one........point is...about the same thing happened to me.....all i did was go to autozone and bought a BNIB maf. pluged it in and turned on right away. reved it past 2500....and put the timing back to what it was. and now im dailing it everyday.....but it can also be a a vaccum leak...so check carefuly b4 you go buying parts.

[santi5222]

check ur fuel pressure it could be ur fuel pump dying out i had that problem too

[SamuraiCJ]

So i face the same problem again this morning. The car would start jerking when it is about to reach 2500 rpm and would not go beyond this rpm.

According to s13zx, it seems to be the MAF thats going out...

[wangan_cruiser]

do you have a check engine light on? mine is on and it is throwing a injector leak. i did my researched and ended up my fuel pressure regulator forcing my injectors to leak. i replaced it and the cel went off. couple of days it turned back on and same thing. i pulled out my fuel rail and checked each injector, all of them were wet from the pintle caps.


but if you want to do your own research try google and type "symptoms of bad fuel pressure regulator" you will find a lot of threads about it from different forum. very helpful

[SamuraiCJ]

Yah my cel is on for 3 years lol

Im not sure about my injectors tho.. what is interesting is that after a run from cold start and turn over the engine couple hours later, the car runs nice and smooth again.

So now i don know what is actually wrong with my 240

[shhyguuy]

Fuel injectors. I had to cut and rewire the injectors with new pigtails because the thin stock wires that go over the intake manifold slowly melted through after 20-some years

[SamuraiCJ]

Fuel injectors. I had to cut and rewire the injectors with new pigtails because the thin stock wires that go over the intake manifold slowly melted through after 20-some years

i checked the wires for fuel injectors and they seem to be fine. the car is not absolutely misfiring so i guess it may not be the injectors.

Note: one interesting thing i found is that my car is only in limp mode when i cold start and run it. after cooling down for couple hours it just run fine, besides i kind of feel that the engine lost power. maybe it is because i only have a bit more than 1/4 tank of gas left and i havent change engine oil for the past half a year.

[SamuraiCJ]

Hi guys,

I just found something interesting this morning. Before i cold start the car this morning, i reseted the ecu about 30 mins before i started it. What i mean reseting is to unplug the negative terminal of the battery and tap the brake couple times.

When i actually cold start the car, the ecu didnt put my car into the limp mode!

I guess this would temporary resolve my problem.

[can24]

i had the same problem and the maf was the answer to mine
:)

[SamuraiCJ]

Yah u guys were right!

Problem solved with a bottle of maf cleaner!

[Nikeboy355]

I think you are going to find out that you have a fuel pressure problem as well...