CAS full counterclockwise???

[bmadd2402]

I have finished my mild rebuild (HG and up) and now I'm setting the timing. The Mech timing is nuts on (99% sure, unless it skipped a tooth!), but when I set it to 15 degrees at 650rpm, the cas is almost all the way anticlockwise. If I set it at 20 deg, it looks better, but then when I plug the tps back in, the timing drops and jumps around (datascan). I have an RB25DET S1 and an AUTO ECU. I have been reading about grounding pin 44, but that seems to apply more to rb20s. also, in datascan, I can see the neutral switch operating. in ConZult, it wants me to set the idle at 900rpm, which I didn't understand. the fsm does not differentiate between auto and manual. I have searched, but nothing really applied or worked for me. Anyone with ideas?

[mello88]

Is the CAS key on your exhaust camshaft broken off? If so you can put the CAS in any way you want, You might have installed it off a tooth. I'd pull it off and reinstall it to be sure. From MOST CAS I have seen, when set the bolts should be around the middle of the slots, but it could vary from engine to engine... GL and when you figure out the problem post a reply for others to learn from.

[Booztd 3]

Is the CAS key on your exhaust camshaft broken off? If so you can put the CAS in any way you want, You might have installed it off a tooth. I'd pull it off and reinstall it to be sure. From MOST CAS I have seen, when set the bolts should be around the middle of the slots, but it could vary from engine to engine... GL and when you figure out the problem post a reply for others to learn from.

2nd on this, check to see if the key on the cam is still in place, and also check to see the key hasnt broken off in the CAS as well, I have had both of these happen to me on VG motors

[Darius]

There was a thread like this on the datalogit user group and the guy was having it with his RB26. He solved it by testing his grounds around his ignitor and found that the ignitor body was not adequatly grounded. He ran a 10 gauge wire from the body of the ignitor to the chassis and the problem was solved. I want to check this out too because I don't think my timing is set properly with the CAS way off to one side even though it has been double checked with a timing light.

[bmadd2402]

yeah I prolly need to ground some stuff. I moved my battery to the back and removed the tray, and all the other grounds are broken or shot. I have one big ground wirefrom the intake mani to the frame, and the ground from the lower harness. I might try adding some more. could that affect things?

[meet07]

I know this is old but I just discover my cas all the way CCW. Has anyone else solved this problem?? Im going to attach a ground this afternoon and see if anything changes....but wanted an update...??

Some one also siad that the exhaust cam gear could have jumped a tooth. Is this possible as well even if the car is pulling hella hard???

Cheers

[Darius]

Yes the car will still run fairly "normal" even if the timing belt has jumped a tooth. By normal, I mean it will run to redline, but the power won't be there. You might think it feels like it is pulling hard, but it would be pulling a heck of a lot harder if the mechanical timing was spot on.

Some people have issues with setting the ignition timing with the TPS disconnected. I am one of them. When I disconnect the TPS, my idle becomes very irratic and surges. It is impossible to set the timing with it surging so I plug the TPS in and set the timing. Doing it this way has never given me any issues.

[240z4u]

I don't unplug my TPS either. The reason your supposed to do it is so the motor goes into an open loop type situation. Never really changed for me one way or another so I no longer bother.

Evan

[meet07]

come to find out, my exhaust cam is off one tooth. now i have also been having some 210+ coolant issues latley. would the timing being off cause heating issues?

[Darius]

Yes, they are probably related. rb250sxdet was having this exact same issue. I helped him reset his timing belt and it corrected both problems.

Retarded timing typically causes high exhaust temps which is seen in the turbo and picked up by the oil and coolant flowing through said turbo.

[meet07]

Ok Im a straight dummy......really. I rechecked the timing marks and they where on the spot?? So since I had the radiator out, and the crank pulley half way off I figured that I would pull the water pump and check it out. Water pump was spotless(motor has about 60k on it). So I put everything back together, bleed the coolant and the reset my timing. Well the only way I could get it at 15 btdc was all the way CCW..........what is going on with this?? Is the computer pulling timing or something??

[placham]

There was a thread like this on the datalogit user group and the guy was having it with his RB26. He solved it by testing his grounds around his ignitor and found that the ignitor body was not adequatly grounded. He ran a 10 gauge wire from the body of the ignitor to the chassis and the problem was solved. I want to check this out too because I don't think my timing is set properly with the CAS way off to one side even though it has been double checked with a timing light.

Darius how do you check it with timing light. I have one of the Snap-on MT2261, and every time I tried to hook-up timing light, RPM reading keeps jumping on display. And I hook it up to one of the longest wires by the ignitor (wire is sticking out and is looped). That's were it appears it should be hooked up according to FSM (rb20det).

[Darius]

You have a way better timing gun than I do. You have the ability to set the gun at 0 btdc, correct? If it is set at 15btdc, then you're looking to line up the orange mark on the crank pulley instead of the 3rd one. Since my timing gun is basic and flashes on the signal to the #1 coil, I set the base ignition timing off of the 3rd mark on the pulley and the bump on the lower timing cover.

You are connecting it to the correct place to receive the signal. Some guys have better luck connecting to the signal wire at the #1 coil instead of at the ignitor.

[placham]

You have a way better timing gun than I do. You have the ability to set the gun at 0 btdc, correct? If it is set at 15btdc, then you're looking to line up the orange mark on the crank pulley instead of the 3rd one. Since my timing gun is basic and flashes on the signal to the #1 coil, I set the base ignition timing off of the 3rd mark on the pulley and the bump on the lower timing cover.

You are connecting it to the correct place to receive the signal. Some guys have better luck connecting to the signal wire at the #1 coil instead of at the ignitor.

Yeah it might be fancy timing gun, but I didn't pay for it nor did I steal it Got it as my tool voucher from "UTI" > As "monster Garage"show would say, FREEBIE FREEBIE FREEBIE

And yes I can retard or advance it accordingly, or set at 0 and watch for mark on wheel, so it has 2 different ways of getting same result.

But when I hook it up to where I said "above" it gets goofy and RPM reading on it jumps up-down. But I havent tried doing directly to #1 coil.

[meet07]

UPDATE!!

I removed my aac valve and tb to clean yesterday. After cleaning i checked a lil bit of my wiring to make sure everything was getting what it needed. Then i went to the ecu and turned the screw CW. Then turned it ccw to check for any codes. I got a coolant temp code but that was b/c i unpluged it while running earlier to see if the idle would drop. Cleared that code and turned the screw on the ecu CW. Ran the car again and adjusted my idle. Then i was like let me check my timing. Looked at the timing mark and wow it was way advanced. Like 45 degrees or something..lol. Lined it back up and wow the cas sensor is back to normal. Figured ill share it. im thinking that the screw on the ecu is suppose to stay cw. even when adjusting the aac valve/idle.