pleas help, fuel cut of @4000 rev 1,2,3,4,5.

[centralcoaster33]

Oh yeah, did you ever measure the pressure in your fuel system?

[allos14]

Hey dude

Na man I think that my pressure is ok, but I will check this weekend to se.

The other day I was messing around with the alarm system and my car started to run excellent, it cud be that the alarm since it has a relay for the fuel pump , may be the relay loses is resistance , the thing is that I don have time to due so I work as a industrial engineer and I got to be designing fixtures or computer chassis and some things for 240sx, but I will get the time , hope that wee can fix this problem , a lot of 240sx owners have the problem , so lets work together in resolving the issue.

Se you dude

[centralcoaster33]

Yeah, I have troubles finding time to work on the car too. Currently I sit at my desk drafting Civil Engineering plans. Are you a CAD junkie? I just went to a seminar at lunch for Civil 3D 2008. My favorite part was the free catered lunch! You might be onto something with the alarm wiring, but that would be something I know nothing about since I still haven't shelled out the $$ for a system.

[allos14]

Cool dude My belly is growing 8hrs in the computer

I design work stations, computer chassis, fixtures, jigs. And yes I use auto cad a lot, pro engineer wildfire 2 , ap 100us to program lasers and punching turrets.

Dude I am getting tired, I need the solution.

I am tired of the problem but not tired of the car

[centralcoaster33]

Hey, do you have a multi-meter (volt-a-meter) tool with a digital display? If so, I've got three tests for your TPS to try. It really should be digital, cause the bouncy wire kind is tough to get numbers from. So, if you got one, let me know and I'll write more. To bad you don't live close by, I have the OBD-II scanner and multi-meter guy in my car now. FYI, I just replaced my TPS, and some how came up on an extra new one, so if you end up needing to buy it, hit me up for a better price.

[centralcoaster33]

Oh, even easier test, unplug the top plug on the TPS (the one with three wires on it). Start engine and see if it idles okay. Now rev it to 2000 or 3000 and back to idle. Any cut outs? If idle is really really bouncy, timing could be off but more likely you have a sticky idle air control valve. Now, with car still idling, turn on heater to 1 or 2, then push in the AC button (lowerleft) and see if that increases idle by 2 or 3 hundred rpms. If it does, then your air conditioner auxiliary air valve is working okay. Now drive around a bit with the top still unplugged and see if you get your fuel cuts out and then report back. Note: my car ran fine with TPS unplugged but I did have to increase my idle a little bit by turning the screw under the throttle pulley so it wouldn't die at an intersection or a sudden let off of gas.

[allos14]

Suite information

My tps is new and calibrated, but I am going to inspect that today, if it works you get your 60 bills and one free silvia bolt key chain “ laser cut”.Ok , and let me print this out so that I can remember the info . good luck with the 600bils and key chain

And thanks for your help on the obd II and tps.

[240sxmech]

60 bucks how about a hundred, like ive told other people before the MAF has a bad ground on our cars it comes and it goes .Run an external ground wire from the MAF connector to right there at the radiator hold down. I was having same problem and checked everything and found this to be my problem so let me know if it works for you. Ill let you know exactly what wire you need to connect your ground wire to tomorrow my car is at my shop.

[allos14]

Today going to work mi car was acting crappy and I started to mess around with the air conditioner, the defroster, the emergency lights, fog lights, and so my car the rpms were changing going up and down, I notice that my brake pedal was more harder to pres felt more powerful, now I was on the freeway and the car had more power so I started to give it more gas, and I pass my limit(80mph) now it was 110mph and the air fuel meter was optimal, my car was perfect.

240sxmech I will due so as you replay and if you are correct you will get your 60dlls and one silvia keychain.

[allos14]

[allos14]

Hello guys

I did what you told me to due, Run an external ground wire from the MAF connector, the air fuel meter started to work better , it stays in one place, but the thing is that the problem is worse. Running extra extra lean, and I had a hard time trying to start my car. So can it be tuning my tps and my timing?

But I think that you may get your 60dlls and one silvia key chain. Let me try that today, if you have any more suggestions pleas tell me.

I notice that when I shut down my car the air fuel meter will be lean , then as the car cools down the meter reads optimal.

And when my car is running and I turn the heater at full, my AFM will go from lean to optimal , it takes some time to due so!

One other thing is , I am in the road and I am going 40mph and give it more gas you will feel the loss of power and the AFM is lean IF I let go the pedal juts a little the meter will jump up to optimal and go back to lean.

[hollbrow]

hey- I had a problem very similar to your a few years ago- after nearly pulling my hair out, I narrowed it down to a bad wire in the MAF harness- looked fine, but the conductor in the wire was worn in two-making an intermittant connection.

Ended up solving the problem by cutting off the whole part of the MAF sensor harness and splicing/soldering in one from a junkyard parts car.

I found the wire problem just by chance- the car got to where it would barely run, and I pulled over by the road and opened the hood- I had been suspecting a MAF problem so I had grabbed the plug at the sensor while it was running and just wiggled it and the rpm changed- I kept fooling with it unitil I was sure there was a bad wire- that's when I just located the junkyard harness and cut it off and spliced it in and the problem went away.

Now take that same scenario- and realize it could be a problem such as that in any of the wiring- and that's where you are.Good luck with it man. That's a hard one.

[240sxmech]

since you ran the ground and the air fuel is staying in one spot and not jumping around sounds like you have a bad maf try a new one or a buddies.Make sure you grounded the ground wire and not one of the signal wires sorry i forgot to check the color of the wire at work i will do that on monday or you can look in a FSM for the wire diagram and it will tell you the color of the ground wire.

[evilMUNK029]

you ever tried cleaning your injectors?..i had the same problem a while back, and i was very puzzled what the problem could be. I luckily cleaned the injectors first and havent had a problem since.Just putting it out there...

[allos14]

Thanks guy

I got some new info, when the car it’s running @ normal temperature the air fuel meter starts to jump. So I started to check the timing and o my god, from 20 degrees I will go down to 5 degrees, and if I disconnect the tps it will go to 20 degrees , so I started to mess around with the timing and couldn’t get it

And the thing is that the tps is new only 6 months , short circuit?Can my timing be of, should I check were the number one piston is?

I notice that when I get of my car . on my left leg I will get a shock , can it be that I have a short circuit ?

The offer went up 70 dlls guys.

[centralcoaster33]

I still think you should drive a day with the top plug of the TPS disconnected. I don't think it helps to flip lights and ac and cruise on and off at random. I think a systematic approach is better. You can try stuff like headlights or wipers also, but take note of which combination of things are on and off and what results you get. First though, just try TPS plugged and unplugged and then ac off then on. Like this:

First disconnect the TPS and verify a smooth idle, everything off like lights and ac and stuff. Let the car warm up, rev it a few times and watch the idle. Still okay? Good. Then drive a little... any cut outs? Still idles okay at intersection? Okay, now drive around with the ac button on and the air at 1 or 2. What happened to the idle rpms? Bouncy or smooth? Higher or lower?

What's it all mean? A: if the car runs fine and idles around 650-700rpms while the TPS is unplugged, then you at least know your MAF is fine (car wont run with no MAF and no TPS). B: if the car runs fine and idles fine with TPS unplugged, then drive around and watch idle at the stop signs. If no cut outs and good idle, then your MAF is still okay and your IACV is probably working okay. If idle gets real bouncy, you could have a sticky IACV. If fuel cut outs persist with TPS disconnected, then TPS is not the problem. C: At a stop, with the TPS still disconnected, turn on the ac button and a little air (1 or 2). Your idle should jump, then drop back but be about 100-150 rpms more than before. Drive around some more and watch the idle at stop signs. If idle is still smooth and rpms are a little higher, then AACV is okay. Now, if you thought your IACV was bad, you can try using the AACV to smooth out the idle and see what results.

I think you could try the above with the MAF unplugged and the TPS plugged for a second round of tests. Again, I think if the MAF is unplugged and the car won't run, then the TPS is bad because at least one must be working and plugged in for the ECM to know what's up or at least guess the air.

As far as grounds and power, the TPS, the MAP (on passenger side strut tower) and I think the EVAP (on top near injectors with three wires and looks like the others (all three plugs look real similar)) all have a common ground and power system, so you can check continuity between all the power wires (green) and it should exist, then you can check between all the ground wires (brown maybe? just not the white ones). That will avoid tracing back to ECM. And if you turn the key on they all run i think 5 volts between the green wires and a ground. You can also check continuity between all the ground wires and the engine and the battery. Finally, get a code reader, verify I'm helping and then send me my keychain! Ha ha, really I just want to hear you fixed it and what you did!

[allos14]

[centralcoaster33]

Hey, hows it coming? Did you try any of my suggestions?

[HOMEMADE240SXTURBO]

ya should change your mafs out.

[Julio Bro!]

60 bucks how about a hundred, like ive told other people before the MAF has a bad ground on our cars it comes and it goes .Run an external ground wire from the MAF connector to right there at the radiator hold down. I was having same problem and checked everything and found this to be my problem so let me know if it works for you. Ill let you know exactly what wire you need to connect your ground wire to tomorrow my car is at my shop.

Hi, I have an idle problem too, it came and went, but now it's continous. In June's issue of Sport Compact Car there's a 240SX buying guide for the S13 (mine is a 1993 SE model) and they mention the problem with a possible solution.

The solution relates to what you say, running an extra ground, but from the IAA unit. The thing is that the IAA doesn't seem to have a ground connection, the wires come from the computer and no ground is specified in the manual; at least, I didn't recognized it.

Reading this thread, the idle problem seems related to the connections of the IAA, TPS, and MAF. I would like to try your MAF ground thing and the IAA too, could you explain which wire from the MAF needs an external ground. And, if you know about the IAA, could you explain too?

[240sxmech]

Yeah no problem monday when i get back to work i will check the wire again sorry been busy at work . Got my motor running again but couldnt push clutch down i think i got my throw out bearing a little crooked when i put the motor back in on friday because i couldnt even move the fork with a prybar so i removed the transmission really quick and noticed that the throw out bearing slid easilly so gonna stab the transmission on monday and see how she goes but ill check the color of the wire for ya.