Problems with 1G Turbo after timing belt replacement.

[DallasN2O]

I have a 1990 Laser RS Turbo, I just purchased from a friend. He recently replaced some parts including the turbo (exhaust side was cracked) with a ported 14b, the belts including the timing belt, and he did the free balance shaft removal. When he cranked up the car after the fact, the timing belt slipped b/c he didnt put enough tension on it. He said it made some clanking noises and he immediately shut it off. At that point he got pissed and sold me the car. Well after I bought it I reinstalled the timing belt, taking great care to follow the instructions and get good tension on it. Ok so after reinstalling I do a compression test and everything looks good.

I don't believe any valves were bent. Well when I crank it now, it wont start the first time I turn it over. Then on the second crank it will start and run. However, it is bogging extremely bad. If you floor it, the rpms climb VERY slowly and at around 5k rpms the rpm needle goes back and forth like crazy. I pulled the plugs to find cheap Champions and black soot and white corrosion all over the tips. So I put them in the bead blaster and clean the plugs up. After reinstalling the plugs all nice and shiny again, the car starts and runs better but not 100%. But as soon as I step on the gas, it goes directly back to the bogging. I pull the plugs again and they look fine.

The car will idle on its own and its staying at about 1k rpm. If you turn on the A/C it almost dies. It seems as if its running very rich and bogging it down for some reason. I'm thinking he may have left something disconnected like a vac hose or a sensor.. but which one could cause this problem? Could it be that the timing belt is a tooth off? How can I check for this? Could there be bent valves even though the comp test was good?

One thing to note: when I installed the timing belt, the crank sprocket TDC mark did not match to the mark on the block at actual TDC ( i put a rod through #1 plug hole ) So I just set it at actual TDC and left the marks off. Its off by about an inch. I'm stumped. Could it be as simple as spark plugs and wires? Someone help a dsm newb.

 

[steve]

One thing to note: when I installed the timing belt, the crank sprocket TDC mark did not match to the mark on the block at actual TDC ( i put a rod through #1 plug hole ) So I just set it at actual TDC and left the marks off. Its off by about an inch. I'm stumped.

The crank pulleys tend to break down first allowing the outer pulley to shift on the hub then it will start to wobble and either fall off or start tearing into the timing cover. If left unchecked they can take out the timing belt. If yours has shifted an inch you won't be able to set the CAS and it needs to be replaced.

No doubt, you'll find a bunch of other issues. You idle and AC problem sounds like a bad ISC.
A intake pressure test (boost leak test) can help you track down any damaged or disconnected vacuum lines.

You might want to invest in a copy of the Factory Service Manual either on paper on on CD.

Steve

 

[DallasN2O]

Forgive me if I misunderstand you, but you are referring to the crank pulley, not the crank sprocket, correct? The marks I was describing are on the crank sprocket. This picture shows what I'm talking about.. except my notch behind the sprocket doesnt line up with the one on the block at TDC like this one shows.

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I don't think it should matter as long as it is timed at TDC, but I thought it may be worth mentioning. Also, what is this ISC and CAS you mention? Again, forgive my newbness and thanks for your help.

Anyone else have any input?

 

[steve]

Sorry about that. After rereading your post it's clear you were talking about the sprocket.
If those timing marks don't line up than you need to make sure that the plate behind the sprocket is on with the right side facing forward. Since you checked TDC by finding the top of the piston travel the only way the crank timing mark could be off is the plate is backward or the crank is bent and that's not likely.

If it's the plate, you can't just leave it on the wrong way. It will rub.

ISC = Idle Speed Controller (bottom side of the throttle body)
CAS = Cam/Crank Angle Sensor (rear end of the intake cam)

Steve

 

[Mist3r Spool]

The reason for the badle idle/no power/no oil pressure/no vacuum is your crank angle sensor. I know we have different cars but I had the EXACT same issue when I first swapped my t-belt and removed my b-shafts. I installed the CAS plate backwards and it was smacking against the sensor...eventually chewed it up. I tried installing washers underneath the sensor to try and compensate for the gap-but it was pretty much a waste of time. I ended up just purchasing a new CAS & blade. Don't worry-I was freakin' out when my car was idling like crap as well-it was just the CAS.

 

[DallasN2O]

I looked at it a few minutes ago and also noticed that my cam gears dont have any dowel pins.. they just have a bolt in holding them on so I can't see where 12 oclock is. Is this normal for a 90 model? If the gears were upside down, wouldnt i have hit valves? Also, if I didnt mention it before, I'm not reading any oil pressure until I rev the motor up and then the needle starts climbing on the pressure gauge. Would a bad CAS cause it to bog and accelerate extremely slow? How can I tell if I'm a tooth off on the timing belt, just the cam gear marks? Thanks for the help guys.

EDIT: I just called autozone and they say there is no listing for cam angle sensor, the only thing they see is a crankshaft position sensor and its $360.00(!).

 

[ddavisaf]

www.misubishigraveyard.com
CPS is the same as a CAS.
www.diamondstarmotorsports.com

Both of those websites have or had CAS' for sale.

Also, put a set of NGK BPR6ES plugs in there. I'll get back to you on the dowell issue, however I'm pretty sure that 90 has dowells also.

 

[DallasN2O]

Ok another update:

The car has been sitting in the garage all day. After getting home from work I get in, turn the key for about 3-4 secs... won't start. I turn the key a second time, it starts. It sounds just like its supposed to, the idle is smooth and steady and just plain sounds perfect. I let the car idle for about 10 minutes to make sure it gets to operating temp. I get back in the car and as SOON as I touch the gas pedal, it immediately starts the rough idling thing again. I press down on the gas pedal and it bogs and climbs in rpm very slowly. It will rev all the way up to redline but it sounds like its flooded and bogging like crazy. As soon as you crank it it makes a loud screeching like a belt is slipping, and it does that on and off. When you hit the gas pedal, and rev it up a little and release the pedal, as the rpms fall back to idle you can hear a soft metallic creaking for just a second. I moved that CAS sensor back and forth while it was idling and all that did was make it idle faster or slower, no improvement in idle quality. It seems that letting the car sit for a long time kindof resets the problem and it will crank and idle fine, until you touch the gas pedal. Surely someone has seen this before. Help! .

 

[Old Mitsu Tech]

Do you have a check engine light? If so, what are the codes? I would use an oscilloscope to check the throttle position sensor for drop outs. Also, the idle stop switch may need adjusted. No power or bogging can be caused by the fuel pump, the fuel filter, the catalytic converter or a timing belt out of adjustment. You must be absolutely sure the marks line up. I set the tension on my belts by tensioning until the pin loosens up in the tensioner and just a little more till it starts to tighten up in the bore of the tensioner. One person recommended a "factory" manual. I have one and recommend you do the same. It can save you hours of nightmares. Also, lastly I have found a few hoses loose on the mass airflow meter which can cause improper air metering. Without hearing and seeing this is all I can think of right now. Let me know if this helps. Rick

 

[DallasN2O]

No check engine lights at all. Thats what is confusing me. As far as the factory service manual goes, where do I get one of those from, since there are no more plymouth dealers. Will it have all of these test procedures youre talking about in there? I have to say this definately strikes me as an electronic or vacuum problem, so I think you are right on target with your suggestions. Where can I find this idle stop switch and can I use a volt meter to test the TPS? I don't have access to an oscilloscope. Thanks for the help, keep it coming!

 

[ddavisaf]

Update your vehicle profile with your complete list of mods.
Stock exhaust? What kind of plugs are in the car?

 

[DallasN2O]

The car is pretty much all stock. The only thing I have is that solid upper intake pipe that the BOV bolts to and an open airbox w/ K&N filter. Stock exhaust. Oh and I just replaced the turbo beause it had cracked exhaust side. I replaced it with a rebuilt ported 14b. The plugs are cheap champions but I bead blasted them clean and it was running before the timing belt replacement with those plugs.

Either my timing is a tooth off, or when the timing belt slipped the first time, it screwed up a sensor. If there is a bad sensor, usually there will be a CEL, correct? If your timing belt is off a tooth, it wont show a CEL will it?

 

[ddavisaf]

No, it won't show a CEL.
Drop the cat, bang it with a hammer and knock all the crap outa there. See if your problem is due to a clogged cat.
You'll need to replace the plugs like I said earlier. Might as well do it now. It'll cost you a massive 9 dollars.
I'm pretty positive that you have dowel's on your cam sprokets. Rotate your cams until you see the dowels. Look at the picture, the dowels are circuled in yellow. If you can't find them take a picture of your cams for me.

 

[DallasN2O]

Yes I figured the dowel thing out, my friend assured me that we positioned them at 12 oclock when we timed it. Plus I went back and looked at it to make sure. I just bought some BPR6ES plugs, they cost like 6.50 here. If it was the cat, would it have acted funny before we replaced the timing belt or is does it happen suddenly? Don't know if I mentioned this before but, the o2 sensor was loose the first time i cranked it after re- replacing the timing belt and was leaking exhaust. I bought an o2 socket and tightened it but it still did the same thing. Could I have a bad o2? But then again, I should have a CEL if that was the case... I think im going to remove the timing cover and re-re-recheck my timing marks and I'll also look at the cat like you said. I'm going to try and test the TPS and ISC also. Will let you know of results. Thanks again.

 

[ddavisaf]

Testing your ISC - http://dmtalon.v8eaters.com/ISC.html
TPS Adjustment - http://www.plymouthlaser.com/tps.htm
If you're still leaking out of your O2 housing, it may be cracked.

Oh by the way, by hammer I meant rubber mallet.

 

[DallasN2O]

I just replaced plugs and wires. No help. I couldn't do the sensor test because my friends volt-meter sucks. I did notice that the negative terminal on the battery is loose but I cant get it very tight because its so old and the metal is soft the nut just digs into it. Ill have to pick up a new one.. but still, I don't think thats the cause of the problem. The car did the same thing it did last time.. when I cranked it, it idled perfect.. I let it warm up then gently pressed the gas, it actually reved a few times like normal, then all of the sudden it starts stuttering and bogging again, the idle speed drops to 500. I just can't understand it.

 

[DallasN2O]

UPDATE:

I found the problem:

Pin 1 and 4 on the coil are not firing. The car was running on 2 cylinders, and because it was 2 and 3 that were firing, it was pretty balanced and you couldnt really tell. SO... my next question is, what all do I need to replace to get this thing going and how difficult is this going to be? Thanks again all for your help and input.

 

[DallasN2O]

I figured out why half of the coil pack wasnt firing. I did ohm tests on it and they both read the same thing, about 9k ohms. So I started to remove the power transistor to do the test on it.. i unplugged the plug out of it and thought to myself, what the hell. So I blew out the connector and plugged it back in and fired up the car. Spun like a top. Now its running great. Oh and by the way, in the troubleshooting process I went to a junkyard and removed a CAS from a 93 Hyundai Elantra w/ 4G63 N/T and swapped mine out with it (had to cut off the plugs because the hyundai plug was different) and it works. Just FYI that the hyundai CAS works on our cars. Thanks again for all the help guys!

 

[Old Mitsu Tech]

No check engine lights at all. Thats what is confusing me. As far as the factory service manual goes, where do I get one of those from, since there are no more plymouth dealers. Will it have all of these test procedures youre talking about in there? I have to say this definately strikes me as an electronic or vacuum problem, so I think you are right on target with your suggestions. Where can I find this idle stop switch and can I use a volt meter to test the TPS? I don't have access to an oscilloscope. Thanks for the help, keep it coming!

Glad you found it. it's good to see someone be a "technician" and not just a parts changer. I tell you I have looked at a lot of "problems" on here and sometimes my advice is only as good as the question posed. If I get bad info, then my reply will not be accurate. My hat is off to a lot of people on here who remote diagnose regularly. Some of them must be dsm psychics . As far as the factory manual. I purchased mine on Ebay. They usually have a few on there and you may have to keep looking to find one to fit your vehicle. Be patient and you will get it. I have one for my 90 awd and it took only a couple of months to find.