transistor and cas

[1995 brian]

does any one know how to test the ignition transistor for a 4g63t engine. the reason i ask is because i have no spark in two cylinders and my coil tested out good so just trying to narrow down the possibilities. also same question for the cas.

 

[bstaley]

http://www.dsmtuners.com/forums/articles-electrical-wiring/229419-how-test-power-transistors.html

As far as the cas I had a problem also, turns out the metal wheel that's on the cam gear had a slight bend and busted the bottom. Are you getting any cels?

 

[1995 brian]

How did you get to the cas? And no i do not have a CEL. Im missing spark in cylinders 2 and 3 (two middle ones) and my engine is cranking but it pauses. Did that with a fully charged battery so dont think thats the problem also tested the coil and it came out within specs. Any ideas.

 

[bstaley]

I replaced a ton of things trying to fix this but the thing that did it was the cas. It only took me like 1-2 hours.

The cas is located under the cam on the back side (the one farthest from the radiator). The bolts on it just happen to hit the cam sprocket if you were to try to take it out as it sits (how convenient). Lol sorry about the rant.

So what I did:

Supported the motor -put a piece of wood on a jack and jacked it up a little to take pressure off the mount

Undid the drivers side mount

Took all belts off

Take timing cover off

Relieve pressure from the timing belt

Take timing belt off

Took the back side sprocket off

Replace cas

Retime and reassemble

 

[1995 brian]

Do you know if theres a way of testing it before i have to di all that?

 

[bstaley]

Do you know if theres a way of testing it before i have to di all that?

At the top of the image you will see the diagram of the ecu with every pin numbered out. Next is the directions on how to check the voltage to make sure they are functioning correctly.

It says while cranking the cas (pin 88) should read .4-3v and while idle should be .5-2v.

After that test i would suggest checking the crank position sensor (pin 89) at cranking should read .4-4v and idle should be 1.5-2.5v.

 

[1995 brian]

Do i check these at the obd port or at the ecm?