CPS pickup coils out of spec

[Kristian_Wraae]

What kind of symptoms would you get if the resistance of the pickup coils are too high?

I've been tracking a misfire for some time but I never bothered to check the CPS until today.

The resistance of the coils are all around 225 ohm.

The TSRM says to replace the CPS if the resistance is not between 140 and 180 ohm. Also the green supports for the pickups have hairline cracks.

 

[Halsupramk3]

if both coils are reading 230 ohms it is probly ok. check to see if either of the wires to the coils will ground out to the cps housing. the coil wires are to be separate from the housing so it should not ground. If you are not sure yours is good i have a rebuilt one with new bearing and seals available. i test the cps on my car before i send it out.

 

[Kai]

IMHO - the resistance is too high - if i were you, i'd definitely get hold of another CPS. My CPS is currently reading bang on 160 Ohm on both coils. There *was*, i believe, TWO specs for the CPS, but jetjock would know more about that.

I have a CPS here that i was going to keep as a spare, but if you want, i can check the resistances and airgaps, and if good, you want it?

Also - with regards to a misfire - check the coil packs. They're 20 years old, and after that long of being heat soaked over the engine, i wouldn't be surprised if they were getting a bit cack. Test the resistance and continuity of the ignition leads, and test the igniter as well while you're at it.

 

[whitemike]

I'm also just curious to know what the symptoms would be.

-Mike

 

[Kai]

Just checked the CPS i have - airgaps are 0.2mm (pretty tight) and resistance on the coil varies no more than 4ohms from each other, all within spec from 159.7 to 163.1 ohms - going spare if you need it.

 

[Kristian_Wraae]

I got a spare from a friend. That one was within specs.

It didn't change anything though.

I have checked the coils and the igniter and they turn out fine. I'm starting to suspect a valve not closing all the way. The compression test is fine though.

Oh well, I'm not spending too much time on this since I have decided to go 2JZ-GTE with the next two months. Just need some spare time to do the swap.

 

[Kai]

What are your valve clearances like?

 

[Kristian_Wraae]

I don't know.

When I first realized I had this problem I had Toyota adjust the valves so I assume it is as it is supposed to be. I was there looking over their shoulder while they were doing it.

Didn't change anything.

 

[Halsupramk3]

you may have a bad plug. also you do realize you have a multiplex ignition system. if the cps and its wiring to the ecu causes a bad signal for an instant the ignitor can cause a misfire. the ignitor is constantly supplied with a .5 tooth signal from cylinder 1. any interuption and a missfire.