help please

[grindin8o8]

okay I bought my cars about 5 months ago. I'm getting tired of something always going wrong with this car. I have a 93 sc400. stock everything except with 18 is350 oem rims and stock supra suspensions with eibach drop springs. I never did get to drive my car 2 weeks straight without a problem.

my problems
stink gassy smell usually on start ups
car dies out at random times on idle at low rpm or when slowing down at a stop light/sign. hasn't happened for awhile now but the weird thing is it started to jerk while driving.
cel comes on SOMETIMES on cold start ups but when it warms up it goes away.
very rough start up.
hydraulic oil fan pump sensor started melting.
car runs like sh!t. very very slow acceleration especially at low rpm's.

I replace my maf sensor. got my sparks plugs changed couple months ago. oil changed couple months ago.

I'm about to give up on this car but I'll give it one more shot before I do. I really don't want to sell it because this car is just a beauty. I'm actually thinking of buying a 97+ sc if I can find one. but no luck so far

I'm thinking it's the ecu, o2 sensors? what else could it be? help please.

 

[Lextreme II]

Check the coils and spark plug wires. Make sure you have spark on all plugs.

 

[grindin8o8]

Check the coils and spark plug wires. Make sure you have spark on all plugs.

I checked the coils it was fine. I noticed on one spark plug wire it looked like it was rubbing on something and I can see the white part. could it be one of the problems? would a wire be causing all of the symptoms im having?

 

[Lextreme II]

If the coils are fine, I would suggest you individually test each wire.

 

[MikeC4C5]

I checked the coils it was fine. I noticed on one spark plug wire it looked like it was rubbing on something and I can see the white part. could it be one of the problems? would a wire be causing all of the symptoms im having?

What do you mean "I can see the white part" ? Do you have spark wire burn through, and is the the white stuff from the coil discharging to something other than the spark plug ?? If this is the case, it is probable that this cylinder is not firing since your spark is not reaching the plug. In turn, this could be the source of your smelling fuel, as there is no burn from this cylinder. This unburned gas vapor will be pushed through your exhaust port and will wreak havic on your O2 sensor telling your ECU that your are running very rich. The ECU in turn will constantly lean out your AFR. Running too long with a cylinder that is pushing unspent fuel vapor through your catalytic converter is also a bad thing. Damage to the catalyst is very possible.

Easy to check if you are throwing spark through a bad wire. Turn your engine on in the dark and look for a light show near the area that is suspect.

Keep us posted....

 

[Amskeptic]

unburned gas vapor will be pushed through your exhaust port and will wreak havic on your O2 sensor telling your ECU that your are running very rich. The ECU in turn will constantly lean out your AFR. Running too long with a cylinder that is pushing unspent fuel vapor through your catalytic converter is also a bad thing. Damage to the catalyst is very possible.
Keep us posted....

Run a diagnostic code check any time you have a check engine malfunction.

Once you decide to enjoy a sophisticated automobile, you must also diagnose said sophisticated automobile with the sophisticated diagnostic tools at your disposal . . . otherwise you will demoralize yourself in short order with expensive guesswork.
Colin

 

[grindin8o8]

okay the problem was my spark plug wires. but one of the problems i had a month ago returned. talk about bad luck ehh??? so I started my car this morning and it idled really rough and the rpm needle was jumping up and down from 0 to 1500 rpm max and back down and up until eventually the car shut off. started the car up again and same thing happened. this happened to me about a month ago as well so what i did before was unplug the maf sensor and car idled a lot better and didn't shut off for awhile. days went by and again it started idling rough and died. it would happen on idle, at stops, or when I'm decelerating. so I bought a new used maf sensor and ran good for about a day then this is when the jerking started happening. weird thing is jerking occurred but the car didn't idle rough or die out. so I fixed the jerking which was caused by the spark plug wires supposedly and once fixed, a day later, start up the car and it's back. car idles rough and shut offs about 10 seconds later. so I did the same thing I did last time this happened to me. I unplug the maf sensor and it idles a lot better and doesn't shut off. wtf??? i plug the maf sensor back in and start it up again and the car runs normals without rough idle. but im sure that the rough idle and car shutting down will return because it happened to me a month ago. and idea guys? im about done with this car because i rarely drove this car because all the problems. I would hate to sell it but i need a reliable car for work and school. so help please.

 

[Amskeptic]

okay the problem was my spark plug wires.

I unplug the maf sensor and it idles a lot better and doesn't shut off. wtf??? i plug the maf sensor back in and start it up again and the car runs normals without rough idle. but im sure that the rough idle and car shutting down will return because it happened to me a month ago.
and idea guys? im about done with this car because i rarely drove this car because all the problems. I would hate to sell it but i need a reliable car for work and school. so help please.

Okay the problem was your sparkplug wires, thanks to Lextreme and Mike C4C5 who pointed that easily observable problem out to you, right?

Now we are back to not-so-observable symptoms that cannot be easily answered by keyboard diagnosticians. You *can* run a diagnostic with no more than a small piece of jumper wire in the diagnostic connector and count the blinks on the CEL. ex:
<http://www.lexls.com/tutorials/intro/codereading.html>

That is the way it is with these sophisticated cars. We can all speculate and give you our favorite problem we had last month or last week, and you can chase problems with part$ galore, but see if you can find out specifically what is bothering your specific car. If you are not devoted to the marque, then I guess you will not invest in a workshop manual. I won't leave the driveway without mine.

There is a caveat here; some problems will not trigger the on-board diagnostics. But it would help us narrow down the thousand and one possibilities if you can tell us the codes or the lack of codes.
Colin

 

[grindin8o8]

Okay the problem was your sparkplug wires, thanks to Lextreme and Mike C4C5 who pointed that easily observable problem out to you, right?

Now we are back to not-so-observable symptoms that cannot be easily answered by keyboard diagnosticians. You *can* run a diagnostic with no more than a small piece of jumper wire in the diagnostic connector and count the blinks on the CEL. ex:
<http://www.lexls.com/tutorials/intro/codereading.html>

That is the way it is with these sophisticated cars. We can all speculate and give you our favorite problem we had last month or last week, and you can chase problems with part$ galore, but see if you can find out specifically what is bothering your specific car. If you are not devoted to the marque, then I guess you will not invest in a workshop manual. I won't leave the driveway without mine.

There is a caveat here; some problems will not trigger the on-board diagnostics. But it would help us narrow down the thousand and one possibilities if you can tell us the codes or the lack of codes.
Colin

i did the diagnostics but it didn't work. my o/d light was blinking conitinuously so i guess nothing wrong with my transmission. my check engine light didn't blink at all. all it did was just stay on. ?? idk I'm pretty sure I followed the steps correctly. maybe my ecu is just broken???

 

[grindin8o8]

update:so i did the diagnostic and I'm pretty sure the code came out to 24. blinks 2 times first, then stops for a bit and blinks another 4 times. code is inake air temperature sensor. funny thing is that I bought a new used one. maybe the one's i bought are faulty as well? or do you guys think that the wiring could be damaged?

 

[Amskeptic]

I would perform the resistance tests in the workshop manual on the intake air temp sensor to either blame it or move on to the next step. On the LS400, which is all I got to go on here, the ECU plug terminals THA to E2 should have a resistance of 2-3 k-ohms at 68* ambient.
Colin

 

[grindin8o8]

I would perform the resistance tests in the workshop manual on the intake air temp sensor to either blame it or move on to the next step. On the LS400, which is all I got to go on here, the ECU plug terminals THA to E2 should have a resistance of 2-3 k-ohms at 68* ambient.
Colin

got a link on how to do this test?? never done one before...

 

[Amskeptic]

I do not. I have the manual. I could not tolerate this car without it.
Colin