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Cas install causing poor performance

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mintalontsi

Proven Member
42
1
Sep 11, 2014
Clifton, New_Jersey
Hi all, for the past couple of months i've had a cel for my cas. Recently it started to get bad with the car breaking up and hesitating under wot. I replaced the broken cas with a new cas from rockauto. I set the motor to where the cam angle marks lined up, installed cas, grounded, and set base timing to 5btdc using an adjustable timing light. I then started the car and noticed that it idles higher at 2k rpm and then goes to 1k once it's at operating temperature. The car used to start at 1500 rpm and drop to 850-1000rpm after a minute or 2 with the broken cas. When driving, the boost isn't hitting as hard (it's more linear vs when it hit hard with the older cas) and it's taking longer to come into boost (15-16psi at 5k vs around 35-38 w/older cas). The car is also hesitating high in the rpm's. I thought maybe it's a boost leak from the throttle body so i replaced the gaskets and torqued to spec and still the same problems. What do you guys think is going on?
 
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Hi all, for the past couple of months i've had a cel for my cas. Recently it started to get bad with the car breaking up and hesitating under wot. I replaced the broken cas with a new cas from rockauto. I set the motor to where the cam angle marks lined up, installed cas, grounded, and set base timing to 5btdc using an adjustable timing light. I then started the car and noticed that it idles higher at 2k rpm and then goes to 1k once it's at operating temperature. The car used to start at 1500 rpm and drop to 850-1000rpm after a minute or 2 with the broken cas. When driving, the boost isn't hitting as hard (it's more linear vs when it hit hard with the older cas) and it's taking longer to come into boost (15-16psi at 5k vs around 35-38 w/older cas). The car is also hesitating high in the rpm's. I thought maybe it's a boost leak from the throttle body so i replaced the gaskets and torqued to spec and still the same problems. What do you guys think is going on?

I know this is a silly question but when using the adjustable timing light did you have the degrees of advanced on the timing light zero out? Or did you have it at 5 degrees before top dead center on the timing light and set the timing mark on the harmonic balancer to 0 "T" on the timing plate on the timing cover.
 
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I know this is a silly question but when using the adjustable timing light did you have the degrees of advanced on the timing light zero out? Or did you have it at 5 degrees before top dead center on the timing light and set the timing mark on the harmonic balancer to 0 "T" on the timing plate on the timing cover.

I had the light set to 5 degrees btdc. I didn't use the timing mark on the harmonic balancer i used the cam gear timing marks because i've read it's more accurate. Will using the harmonic balancer for timing make a difference from using the cam timing marks?
 
I had the light set to 5 degrees btdc. I didn't use the timing mark on the harmonic balancer i used the cam gear timing marks because i've read it's more accurate. Will using the harmonic balancer for timing make a difference from using the cam timing marks?

I've always used the harmonic balancer and the timing covers hash marks. I would set it that way and set your timing light at 5 degrees before top dead center and shoot for the "T" on the hash marks on the lower timing cover. Then if you want to double-check on the timing gears since your timing light will be adjusted to 5 degrees before top dead center.
 
Earlier today i went to attempt to time the motor using the harmonic balancer. I have an aftermarket harmonic balancer and there aren't any timing mark on it for me to even begin. There are no indentations or marks. What's my next option?
 
Earlier today i went to attempt to time the motor using the harmonic balancer. I have an aftermarket harmonic balancer and there aren't any timing mark on it for me to even begin. There are no indentations or marks. What's my next option?

What type of aftermarket harmonic balancer do you have? I've never seen a harmonic balancer that didn't have a timing mark on it. I would get or put the stock harmonic balancer back on. If you still have it. If not I would purchase or borrow one. Is the pulley one of those unorthodox racing aluminum pulleys? If it is get rid of that thing. They don't have dampeners on them. And can cause unwanted harmonic vibrations on the crank.
 
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This is a bad idea, never rotate the crank in the opposite direction (counterclockwise). You will risk jumping mechanical timing. Instead use a dial indicator with an extension to find true top dead center. Or use a long screwdriver and Visually observe it when it stops moving at the top of the stroke. Verify it's on the compression stroke by putting a paper towel or hand over spark plug hole and feel for pressure or watch the paper towel push off of spark plug hole.
 
I have used this method on many various engines, not only 4G63, with no jumping of mechanical timing. You will find TDC with your method as well, but the method I linked to is the correct way to find true TDC. This is also the procedure cam manufactors refer to findin true TDC when timing cams.
 
I have used this method on many various engines, not only 4G63, with no jumping of mechanical timing. You will find TDC with your method as well, but the method I linked to is the correct way to find true TDC. This is also the procedure cam manufactors refer to findin true TDC when timing cams.
Do it however you want. Just because you have done it on your engines depending on the design of the tension system and lucked out with the 4g63. Doesn't mean you are not risking jumping time on cams because of slack in belt and spring force on cams by rotating it backwards. Your taking unnecessary risk and it is not advised. One other thing the method with the dial indicator will be much more accurate than with a stop.
 
The OP was asking about electronic timing after he replaced CAS. Not mech timing (although it always doesn't hurt to check it when having issues) but his car was fine till he replaced the CAS and reset electronic timing.
 
FWIW the piston stop method is way more accurate than the dial indicator because of piston dwell. When the piston is at TDC there almost zero up & down movement from crank rotations. When you use the stop method you get the piston awwayfrom TDC & the dwell.
 
What type of aftermarket harmonic balancer do you have? I've never seen a harmonic balancer that didn't have a timing mark on it. I would get or put the stock harmonic balancer back on. If you still have it. If not I would purchase or borrow one. Is the pulley one of those unorthodox racing aluminum pulleys? If it is get rid of that thing. They don't have dampeners on them. And can cause unwanted harmonic vibrations on the crank.

It's a "toms"ebay crank pulley. I know most ebay stuff is junk. I ordered this unit back when i did my timing belt and it looked decent so i used that instead of the oem. I had it on for about 100 miles and thought "maybe this is a bad idea". I took the ebay unit off and put the oem back on and after about 25 miles the oem unit separated from the rubber damper and i was back to having the ebay unit on. No problems so far besides the non existent timing marks.
 
FWIW the piston stop method is way more accurate than the dial indicator because of piston dwell. When the piston is at TDC there almost zero up & down movement from crank rotations. When you use the stop method you get the piston awwayfrom TDC & the dwell.

I tried again with getting the cas to work. I put a screw driver in #1 cylinder and manually rotated the engine until the piston was at it's highest and the cam timing marks aligned. I then re-installed the cas and went through the manuals directions for setting timing. I used the cam timing marks at 5btdc. when all was set and done i drove the car and the cel comes on after +/- 1 mile. I'm starting to think that this after market cas is junk. I'm trying to find a used oem cas.
 
What type of aftermarket harmonic balancer do you have? I've never seen a harmonic balancer that didn't have a timing mark on it. I would get or put the stock harmonic balancer back on. If you still have it. If not I would purchase or borrow one. Is the pulley one of those unorthodox racing aluminum pulleys? If it is get rid of that thing. They don't have dampeners on them. And can cause unwanted harmonic vibrations on the crank.

I'm not opposed to putting another oem cp and re-timing but, i'm not convinced that will solve my issue.
 
I put a screw driver in #1 cylinder and manually rotated the engine until the piston was at it's highest and the cam timing marks aligned. I then re-installed the cas and went through the manuals directions for setting timing. I used the cam timing marks at 5btdc. when all was set and done i drove the car and the cel comes on after +/- 1 mile. I'm starting to think that this after market cas is junk. I'm trying to find a used oem cas.
I'm not opposed to putting another oem cp and re-timing but, i'm not convinced that will solve my issue.


Ok just want to make sure of some info. You verified you were on the compression stroke when you brought the #1 piston to TDC by putting your hand or a paper town over the spark plug well to verify it was pushing air out (pressurizing) right? And when you reinstalled the CAS you lined up the cam sensor mark with the mark on the body of the CAS correct (see pic below)? Then you grounded the ECU and set time with the a adjustable timing light set at 5* btdc using the Cam gear timing marks. I would still get a OEM harmonic balancer to verify/cross reference you are setting the Elec timing correctly. What does the CEL code reference (CAS)? But if you think its the CAS then test it. Below are good threads.
CAS diagnosing steps?
How to test 1g CAS?

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Ok just want to make sure of some info. You verified you were on the compression stroke when you brought the #1 piston to TDC by putting your hand or a paper town over the spark plug well to verify it was pushing air out (pressurizing) right? And when you reinstalled the CAS you lined up the cam sensor mark with the mark on the body of the CAS correct (see pic below)? Then you grounded the ECU and set time with the a adjustable timing light set at 5* btdc using the Cam gear timing marks. I would still get a OEM harmonic balancer to verify/cross reference you are setting the Elec timing correctly. What does the CEL code reference (CAS)? But if you think its the CAS then test it. Below are good threads.
CAS diagnosing steps?
How to test 1g CAS?

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yes to all. I had re-did the whole cas install and timing procedure just to make sure. This is very strange. I no longer have a cel (code 22). The car is still hitting full boost at 5k and back firing high in the rpm's. I figure it has the this aftermarket cas. I'll test it later. I also picked up a used cas for cheap. I'm gonna try and swap it in tonight and see if that solves it.
 
I attempted to test the rockauto cas last night and i wasn't getting any readings so i installed the used cas and then afterwards i read that i have to have it on the car while testing to check for spark, so there goes that. I installed the used cas w/ idle set at 750rpm and timed to 5 degrees per the adjustable light. However, after i shut the car off, disconnect the timing ground and restart and re-checked timing it was at 13 degrees instead of 7-9 per the manual. The car was stalling after startup w/ the idle set at 750 so i grounded diagnostic pin and set to 1k rpm and re-checked timing and then it was at 18 degrees. On the test drive the car seems to be at it's regular performance level and no more breaking up high in the rpm's, backfiring or ridiculous turbo lag. I'm still going to test drive it again later or tomorrow. I know that timing goes up with idle but will 18 degree's at idle hinder the performance?
 
So, i finally got around to test driving the car again. The used cas i previously had installed still threw the cel and the performance seemed lesser than before this whole cas nonsense. I put the rockauto cas back in and did everything exactly as the manual says. She started up fine then i went to the store and when i went to restart it just kept cranking before finally starting from me applying partial throttle. I'm starting to think that the cas isn't the problem but maybe the ecu. I'm going to check the capacitors when i get a chance. Is there anything else that can be causing this? Can anyone suggest any other possible causes of this issue?
 
Fill out you dsm profile so we can see what your set up is. Boost leak test to at least 15psi using soap and water and spray all possible leak areas. (Do you have a Logger) is any of the data values off for any of the sensors MAF/IATS, TPS, CTS, O2 voltage, ISC, INJP? Verify the TPS is adjusted properly and getting proper signal. Check that the electrical wires on the harness side of the connectors of the CAS and TPS are not damaged and are seated in connector correctly. Check spark and associated electrical devices that supply it, PT, coil, plug wires, plugs. Verify mech timing. Check condition of ECU. I would still set timing the old fashioned way with the hash marks.
 
A mis-adjusted cas will sure make the car run bad. I did a simple oring replacement and scribed 3 marks on the edge of it to put it exactly back in place. Well that didnt work so once I timed it properly, as you have, my car runs fine and no cel. Just 02. These can be tempermental.
 
I just saw that you updated your dsm profile and that you are using dsm/ecmlink. When you are grounding the ecu to set timing are you using the ground timing/diagnostics connector found under Misc. Tab in V3 in ecmlink? Instead of grounding the connector on fire wall?
 
I pulled the ecu yesterday to check for capacitor damage and anything else that shouldn't be and everything looks good. As it turns out i don't have dsmlink. I was told the car was tuned via dsmlink by the previous owner and just took his word for it. From the research i did online, it looks like it's a key driver tune. The eprom chip is labeled, "75/60/AWD 11:1 KNOCK 560cc NO LOWER HC"
 

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A mis-adjusted cas will sure make the car run bad. I did a simple oring replacement and scribed 3 marks on the edge of it to put it exactly back in place. Well that didnt work so once I timed it properly, as you have, my car runs fine and no cel. Just 02. These can be tempermental.
I've adjusted and re-adjusted about 4 times between the rockauto cas and a used mitsubishi unit. The used unit i time to 5btdc and then once i remove timing ground and re-check timing is at 13 and when i raise my idle to 900-1000rpm it's at 18.
 
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