My car is still acting up. So now the car still idles like sh*t. So last night I go and start the car up and its starts acting funny. It stays at 2000 rpm and If you put the clutch in the rpms would go up. then starts idle surging. So i pull it in the garage and shut it and let it sit. So today I go out there and start it up and its warming up and the rpms are coming down and then it starts surging again so i shut it off and then start it again and it seems to be working fine. but it still surges alittle then when you rev it to say 5g let it go it will die. The isc is rebuilt and the throttle position sensor tested ok when the throttle body was rebuilt. I got a logger the yesterday and set the tps. I'm not sure what the hell could be causing this. My cas is leaking and it seems to be making a noise. So I was wanting to know if the cas could be causing this?
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It definitely could be..... If the CAS is not working properly then your spark probably isn't firing at the right time. It would seem odd to me that the CAS would display irratic behavior like that, but i guess its possible. Do you have a timing light to check the timing on the crank pulley? That would be a good way to figure out if the CAS is working.
I don't have a timing light. But on the logger it shows timing and it seemed to be all over the place.
Well then the CAS makes sense. The CAS isn't the only thing that caun cause that, but if it is going out then it will..... I know a CAS is fairly expensive. The only other options that i can think of that would cause that problem are the wiring to the CAS and the ECU, but the both of those are going to be tough to check. Maybe try to find a test procedure to test the CAS with a Digital Multi Meter if you have the shop manual or try to get your hands on a CAS you know is good.
autobahntom
Well-known member
One way to test the CAS is to take it off the engine. Plug it back into the car. Then rotate it by hand (key on/engine off); put your other hand on each injector. As you turn the CAS, each injector should click as it 'fires'.
Tom
Tom
^^^ I just did that and they all seem to be firing.
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I put all back together and adjusted the throttle stop out alittle and it seems to be idling better. But when you rev to 3g when it comes down it seems like it catchs its self and surges for a couple of secs and levels back off again. But when rev to 5g and let it come down it will just die. What can be causing this?
I pulled the ecu and it looks like its got stuff on it. So I took a pic to get your guys advice.
It looks to me like someone sprayed it with clear lacquer or something after changing the caps. It also appears that perhaps one of the ISC driver chips has been replaced. Looks very clean otherwise.
Ok thanks keydiver that eliminates the ecu. What could be causing this idle issue?
Is your timing still all over the place while at idle?
I put ecu back in the car and started it up and let it run and I rev it to 3g and let it go and it caught its self and level back out then rev'd it a couple times to 5g and let it go and it acted like it was going to die then the rpms picked back up and leveled off. But after 15 mins or so it started surging. The timing seemed to be working good it wasn't all over the place. Could this be a o2 sensor?
stevep
Well-known member
Does the underside of the top case have writing in black sharpie on it?
Like Jeff noted IC107 looks unusual as does the black plastic capacitor C25 next to the CPU.
Have you checked to make sure your IPS is functional and checked your ISC?
Like Jeff noted IC107 looks unusual as does the black plastic capacitor C25 next to the CPU.
Have you checked to make sure your IPS is functional and checked your ISC?
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I didn't really pay attention to the underside of the case. The isc motor is rebuilt and the ips was checked out good when i had the throttle body redone. That was less than a month ago.
stevep
Well-known member
None of that means a thing today.
The IPS requires proper grounding to function and without it the ECU doesn't get notified that the throttle is closed.
Coils in the ISC go bad all the time. The only way to know right now if either are good is to check them.
The IPS requires proper grounding to function and without it the ECU doesn't get notified that the throttle is closed.
Coils in the ISC go bad all the time. The only way to know right now if either are good is to check them.
On my logger the isc is reading 35.1 percent. Is that good? How do you check the IPS and where should it be at to be good?
stevep
Well-known member
I went to oreillys and bought a brand new isc and its still doing the same thing. I don't what the f*** is causing this.
