89 240sx SOHC sputtering/bad idle

[xKnownShadowX]

I checked that today and there's no hissing or anything coming out of it.I'll recheck that thanks.

So I got the FSM to work finally and I'm doing test.I first did the TPS ohms test and when it's not touched its at 5-6ohms then open it goes 6....7...8....9....8... something like that as it opens.IDK how to do the test very well.

I moved on to the o2 sensor and put it in mode 1.Supposely the green LED suppose to flash 5 times within a second range of hold idle at 2000RPM, well mine only flashed twice.It's a brand new BOSCH o2 sensor dunno if those are bad.I'll edit this as I go.

Mode 2 both red and green light come on together which it suppose to mean mixture ratio is good?!

Mode 3 codes: 13,35,41
I disconnected the air temp sensor and coolant when the car was running so those are good just haven't cleared them.Code 35 which I don't understand cause my car never came with one to begin with.

Mode 4 red light comes on when I turn the key but it doesn't when I depress throttle so it means my TPS is bad.I'm gonna swap it see if that works.If not then a shame I gotta waste $100 on a new one.

Neither work so in conclusion it can be the harness or both TPS are bad.Starting to think it could be a bad TPS or it's not getting power or something.....errrggg....

[compactfean]

There are two tests needed to test tps. Ohm it out and set voltage base and check the sweap on both as you open throttle. On SR .45 is base voltage with throttle close and throttle body. Screw barely up keeping buttery from sticking

[xKnownShadowX]

I did the mode 4 TPS test and the ECU doesn't read it when I press down throttle.Any idea?Maybe no signal?

[compactfean]

Test it with dvom. If your specs are good at the tps ( which I doubt) then check to see what your voltage is from closed. To wot. If you have any sudden spikes up or down its bad. If you can't get the voltage low enough its bad. Can't get it High enough its bad. Voltage should smoothly go from. 45 v to 4.xx. v. Then get the ecu pinout and find tps input and test it the same way. You are trying to use the self diagnosis function of the ecu which will not detect these issues.

[xKnownShadowX]

I tried back probing and I get no voltage at all.Though when the car is on the harness has like a 5v and one has 24v or I think 12v

Maybe when I moved the ECU one wire got cut or something?

[compactfean]

Well that sounds kind of normal maybe ....one wire should be 12v with key in the run position. The wires you want to backprobe are the ground and signal wires. Black goes to ground red goes to signal. If your having trouble with reading your meter just. Put your leads straight to the battery and adjust it till you get hundredths of a volt (example 12.32 volts) if you have 5volts commingle from signal with throttle closed try adjusting it down. If it wont than that's your problem. Ecu thinks your wot all the time.

[compactfean]

I just checked my car and if your rocking a manual trans than signal should be the middle white wire.. I have no idea what wires for an a/t tps.

[NicUzumaki]

stick a pin into the back of the red wire on the tps harness, set your voltmeter to read 20 ohms. u want between .45-.55

but adjust it with the ignition on,
once you find the sweet spot unplug the tps
for about 10 seconds. turn the ignition to off
plug it back it, then start the car. this makes the
ecu realize it has to re look at it.
also if there are two wiring clips coming off your tps
one is the actual tps the other is a idle sensor.

[xKnownShadowX]

Thanks guys I shall do that in the morning. Hopefully it's not a bad TPS.I tested my IACV and IACC or w.e. and they all are fine but the one that sits on the inside part of the intake might be clogged or leaking I read so I gotta check that out.

I have my car sitting with the negative disconnected so it clears codes so I'll update later/tomorrow since I haven't slept lol.

[gijoe392003]

The reason you are getting code 35 Exhaust Temp Sensor is because you have a California computer. That code comes up all the time for me, but I just put a resistor in the plug and it stopped.

[coolbone28]

Ok...firsr you need to re-calibrate your TPS. It should be ~0.4v closed and should climb linearly when the throttle is oppened to ~4.0v

Once that is done you need to check to make sure the timing is set correctly. THEN you adjust idle with the Idle control screw...which is part of the IACV assembly.

[xKnownShadowX]

having trouble borrowing a timing light.I recently put 91 gas and it feels better and doesn't do it as much but it's there.

[xKnownShadowX]

Got a good update.I went and got a hold of my high school auto ROP teacher and went over to the shop today.We tested the TPS with the snap-on vantage or something like that and everything works and is set right.I plugged the IAC solenoid in and for some odd reason car was idling perfect.Cool I said now it runs.The missing was still there though so he said it might be my timing, something I wanted to test for awhile now.Finally got the timing light and checked it there and funny thing my friend's dad had supposely set it to *15 well it read *24.Daaaammmmnnn hella off so I put it back to *15 and the missing kinda went awhile but still present.

Anyways the car was fine as I drove it but the sputtering was light weight there.I get down 1.5 blocks and the idle rises to 1.5k when at idle.I parked disconnected that damn solenoid and car idled fine.It drove alright and a tad bit better.

He also suggested I take my timing cover off and make sure everything on the guides and chain are correct followed by checking cam, lobes, lifters to make sure all is good.He also suggested a oil pressure gauge since it seems like I'm losing oil pressure or not getting enough somewhere?!?!Anyways I take his suggestions as gold since he has done racing all his life.

Tonight I drive back home and well all hell broke loose.Car runs fine, everything was good until I WOT!!!HOLY CRAP ITS LIKE IM IN COMPTON GETTING SHOT AT!!!The sputter got 100 times worse.DAMMIT!!!I wanna recheck my timing but people are being really ratarded with loaning or saying they can get one and can't.I'm just gonna buy one.Then I need to change my cap,rotor, and plugs they are somewhat old.

Car's getting my head hott next thing on the list is shoot it up and roll it off a cliff.We all know it won't happen but in my dream tonight it shall.Suggestions would be highly appreciated.Thanks.

[compactfean]

Have you checked your fuel pressure yet? I'm just wondering.

[xKnownShadowX]

Nope I'm gonna go on that since I got slight bit of money now.I was reading up and people said it can be loose plugs to bad gaps.

[xKnownShadowX]

So this what I ended up doing.New NGK plugs, correct gap, problem solved.

Here's everything I did end up doing.

Tested all components, ecu codes, set timing, checked resistance, checked voltage, etc.Set TPS correctly and replaced spark plug wires and plugs.I need to get the fuel gauge asap though.Thanks for the help if problem comes back then I'll post and if I solve it again I'll post thanks.