I drove for over 2 hours when I bought the car...I do have a feeling it's an electrical problem, the wires are a mess with bad connections everywhere! It's also equipped with a SupraStick comp, don't know it the wires from the ISCV go to that, but that's where the bulk of the mess is.
Desperately need a working ISCV for a 1j!
- Thread starter shoo_itt
- Start date
I cant tell you the right one because i have a chaser harness. However i know that it comes from one of the dash plugs not from the ecu. In my harness it was 1 thick, either black or black/red i don't remember, wire that feed both.
I don't know if you solved this or not yet and you may not have the same problem I did but I just thought I'd give you another thing to check.
I had a high idle issue too and I thought for sure it was the ISC. It ran that way for a while and eventually it got to the point where one day I went out to start the car and trouble shoot some more and it wouldn't start at all. Normally, I would think ECU but I had a good feeling that mine was good because I had replaced the caps within the year so I decided to check out some of the sensor inputs to it. I started with the crank sensor. It measured the correct resistance value but since that's only part of the validation and I didn't have and Oscilloscope to to check the pulse frequency, I just decided to buy a new sensor. Once I replaced it the problems were gone, it started right up and no more high idle.
I had a high idle issue too and I thought for sure it was the ISC. It ran that way for a while and eventually it got to the point where one day I went out to start the car and trouble shoot some more and it wouldn't start at all. Normally, I would think ECU but I had a good feeling that mine was good because I had replaced the caps within the year so I decided to check out some of the sensor inputs to it. I started with the crank sensor. It measured the correct resistance value but since that's only part of the validation and I didn't have and Oscilloscope to to check the pulse frequency, I just decided to buy a new sensor. Once I replaced it the problems were gone, it started right up and no more high idle.
...well after testing, it turns out my ISCV isn't connected to anything, i couldn't get 12volts from any of the wires. 2 of them should be 12v, i'm guessing one of them is ground...the other 3 could be airflow, temperature and rpm????
@ zoppii: Was yours showing the same symptoms as mine? ie, good when cold then really high when hot and even higher when in park?
@ zoppii: Was yours showing the same symptoms as mine? ie, good when cold then really high when hot and even higher when in park?
Yes, the same symptoms as yours except the park thing because I have a manual. The shift to park rev increase is logical anyway as there is an idle up for park even in normal conditions.
I would think if I would have been able to hook up an Oscilloscope to my sensor I would have seen a normal wave pattern coming from the crank sensor when cold but when hot it would have changed because the sensor was reacting or failing only when hot. I work on circuit boards all day long at my job and we see heat related failures in coils periodically and essentially the sensor has a coil internally as the main component. The windings will expand during heat and latent failures related to shielding can surface and change the output signal. I thought about taking it apart to evaluate it but it's potted so much that I figured I would destroy the evidence just trying to get to the coil.
Even if it wasn't the cause I couldn't go wrong replacing a 15 year old coil with a new one for $125.00. It's a pretty critical part especially when you're pushing 425+ hp out of an engine.
I would think if I would have been able to hook up an Oscilloscope to my sensor I would have seen a normal wave pattern coming from the crank sensor when cold but when hot it would have changed because the sensor was reacting or failing only when hot. I work on circuit boards all day long at my job and we see heat related failures in coils periodically and essentially the sensor has a coil internally as the main component. The windings will expand during heat and latent failures related to shielding can surface and change the output signal. I thought about taking it apart to evaluate it but it's potted so much that I figured I would destroy the evidence just trying to get to the coil.
Even if it wasn't the cause I couldn't go wrong replacing a 15 year old coil with a new one for $125.00. It's a pretty critical part especially when you're pushing 425+ hp out of an engine.
wow you're smart! Ok, I'll look around for a crank sensor. Parts are quite hard to come by around here but I might be lucky...
But it still doesn't explain why I'm not getting any voltage from the ISCV plug, I'm still guessing it's not connected to anything.
But it still doesn't explain why I'm not getting any voltage from the ISCV plug, I'm still guessing it's not connected to anything.
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Disclaimer - Here again, I have no idea if this is your specific problem or not so please validate your own situation. I simply wanted to give you another place to look in case the more obvious yielded no results.
Good Luck.
Good Luck.
zoppii;1615319 said:
I'm probably not going to do what you said anyway, thanks for the suggestion though.
So, I was just playing with the throttle screw and I set it so it JUST idles without dying when it's cold and in Drive. Now, when it warms up it's a hell of a lot better, no longer near 2,000rpm but right on 1,000. It's still a little high but, considering the weight of the Volvo, this amount of revs only just gets it rolling in idle gear. I don't know the exact rpm 'cos the Volvo has gauges for a 4cylinder, but just by listening it's clearly better.
I'm gonna say this problem is solved and would like to thank te72 for his original suggestion of just turning the throttle screw and RockPaperSwoRD for the ISCV, now I have a spare! :icon_bigg
Be sure to see more threads by me.
-shoo_itt
It's a '91 240gle Wagon, still a work in progress. These are old photos, the grille is now all black with a Ferrari look alike Volvo "Prancing Moose" Emblem. When it's registered I'm putting some Matte Black 17's on it which I bought from a company in America called iPd (some of you probably know of them), new exterior lighting, speakers, etc.
It's a Toyota forum so I didn't think the Volvo was too important lol...just the engine.
It's a Toyota forum so I didn't think the Volvo was too important lol...just the engine.
