Balancer Issue?

Tim Groth

SCCoA Member
I've never had balancer failure on any of my 94/95s so want to hear everyones thoughts. As this is what I am leaning towards based on my SC experience over the years.

Just recently did headgaskets, Timing Cover gasket, New water pump on my 95. Timing was set correctly as I've been there and done that 100 times. Also at that time or within the last 1000 miles car has had - new Plugs, Taylor Wires, Cam Sensor. I also installed a MP Crank Pulley, 5% pulley, MPII, MP Intake, PP 75mm Throttle Body, Kooks shorties, Full Exhaust, and new to me 4r70w.

When first put back together car had plenty of pep and no issues. Now it has hesitation at times and other times tons of power. Not really a plug issue as sometimes under boost it sings, others it stumbles.

This morning idle was fine...went to pull out of my driveway and it was basically in a limp mode...wouldn't go over 10mph hardly enough power to pull up the hill. Since I had to get to work I didn't check wobble but to me it seems like it fits the bill.

My 89-93 SC's were either all or nothing when the balancer went so just searching for thoughts.

-Tim
 
Tim,

What you are describing sounds more like a bad DIS module than a problem with the balancer. The only reason a balancer would cause those issues is if the balancer's inner hub was broken and that allowed the trigger wheel for crank sensor to get out of phase, or it was wobbling bad enough to loose contact with the crank sensor. If that was the case it would be pretty apparent just by looking at it. I agree, that most crank sensor failures are an all or nothing deal...either it works or doesn't.

Oh yeah...I have seen a few cars that had the supercharger belt rub through the crank sensor harness and it caused intermittent issues.

David
 
Cats, if it has them could be moving around. My 5.0 did what you say. On my na 3.8 stang the balancer key way wollered out and it had absolutly no ~~~ at any time. Did everything looking for a problem. Them one day went to pull the front cover off to check for something(don't remember what) took the balancer bolt out and pulled the balancer off by hand. I wasn't as smart about the 3.8 then as I am now but I knew that wasn't right. Looked at the keyway and it was about twice as wide as it should be. Replaced balancer and all was good.

When my balancer went bad on my black car, I started it up one time and the motor shook like it was down a cylinder I reved it real quick and it cleaned up. Was in a hurry to get home so didn't think much of it. Got on the highway and a ricer comes hauling up on me so I punched it and bang car stopped running. Ricer was prolly having a good laugh. Pulled over and got towed home. Turns out it broke the crank snout off. But had plenty of power before it went.
 
Tim,

What you are describing sounds more like a bad DIS module than a problem with the balancer. The only reason a balancer would cause those issues is if the balancer's inner hub was broken and that allowed the trigger wheel for crank sensor to get out of phase, or it was wobbling bad enough to loose contact with the crank sensor. If that was the case it would be pretty apparent just by looking at it. I agree, that most crank sensor failures are an all or nothing deal...either it works or doesn't.

Oh yeah...I have seen a few cars that had the supercharger belt rub through the crank sensor harness and it caused intermittent issues.

David

I believe on the 94/95 damper the pick up ring mounts to the inner hub on the balancer so even if the outer part of the damper started moving the inner ring stays fixed to the inner hub and stays in sync. I agree with your DIS theory.
 
I believe on the 94/95 damper the pick up ring mounts to the inner hub on the balancer so even if the outer part of the damper started moving the inner ring stays fixed to the inner hub and stays in sync. I agree with your DIS theory.

I understand, but I was talking about a situation like this, where the inner hub breaks off and remains on the keyed portion of crank and only the crank bolt is holding the remainder of the balancer on.

http://www.sccoa.com/forums/showthread.php?t=110298&highlight=broken+balancer

David
 
I have 3 other EDIS modules kicking around I will give it a try but again haven't heard of one going bad similar to the earlier years.

Car is catless so can mark that off... I did extend the O2's since I now have the kook mid-lengths...I wouldn't think a bad O2 would cause these symptoms tho.

I do have the CTS unplugged also so the fan stays on...could be the problem but again, usually that effects start up more so than drivability.

Could be a fuel issue? Car did sit for over a year...I think a plugged Filter would have shown up sooner though?

-Tim
 
Alright - home from work. I plugged the CTSensor in - Still same symptoms however now the Check Engine light is off...guess with that being said that rules out all other sensors having any issues.

Car idles smooth - maybe a small vac leak since guage sits on 17ish but nothing that would cause what is described above.

Balancer didn't appear to have wobble - when car is given Boost of 5psi or more it acts as tho something is plugged up. The blower whines the needle pegs and nothing happens :rolleyes:.

I'll swap out the EDIS for kicks and giggles...keep the suggestions coming as I am currently stumped. Next trip will be for a fuel filter given the time that car sat its all I can think of next.

-Tim
 
Well the confusion continues. Replaced the EDIS Module as suggested - no change over prior symptoms.

I noticed the car was low on fuel and thought perhaps that was the problem...Filled it up w 93 - still hesitation at times and strong power at other

Made a round trip of 200 miles on the car all highway and the car ran fine. Had a few times where I kicked down on it car, easily buries the boost guage and pulls hard. At lower rpms with cruise set it did feel at times like it was missing and had no balls.

Still scratching my head.:confused:

-Tim
 
Well the confusion continues. Replaced the EDIS Module as suggested - no change over prior symptoms.

I noticed the car was low on fuel and thought perhaps that was the problem...Filled it up w 93 - still hesitation at times and strong power at other

Made a round trip of 200 miles on the car all highway and the car ran fine. Had a few times where I kicked down on it car, easily buries the boost guage and pulls hard. At lower rpms with cruise set it did feel at times like it was missing and had no balls.

Still scratching my head.:confused:

-Tim

That is a head scratcher. At WOT the car pulls fine but at part throttle runs poorly? I would look for a vacuum leak.
 
This morning the car threw the main serp belt while exiting my subdivision. It also threw a belt when I put the car back together 3 weeks ago. First belt was a brand new Dayco Belt and well this second one was a junk belt from a parts car. I have the new belt waiting to be installed, guess now I am prompted to do so.

Car has the MP 10% Crank Pulley on it, which is the only after market pulley changed on that belt routing...has anyone had troubles with it?

I've never thrown just a belt with a bad balancer...usually the balancer has fallen off too.

-Tim
 
I've never thrown just a belt with a bad balancer...usually the balancer has fallen off too.

-Tim

SOMETHING is out of true.

I've had the "Throws belts but not the balancer" on another car, not a SC. I wouldn't discount it.

Sounds like it may be time to use a long straight edge (yardstick or something similar) and see how the pulleys line up.

RwP
 
Check the fuel pressure to make sure it is increasing pound for pound with boost. The small vacuum/boost refrence hose may have fallen off the fuel pressure regulator.

David
 
Well figured out half of the equation tonight, and damn do I feel stupid.

Installed the new belt tonight, after loosing half of my coolant and cussing the aftermarket lower hose that barely fits over the water pump outlet I start the car.

Belt immediately throws again. First thought was coolant on the belt made it throw. Install again, come around the car...again off. At this point I think perhaps the aftermarket tensioner pulley isn't wide enough to keep the belt from walking so I install a stock pulley. Start again...same result.

After doing this 5 times, it comes to my attention my accessory bracket on the drivers side only has 1 of the 3 mounting bolts holding it to the head. This time putting the car back together I left off the WP to PS bracket as others have...would figure my first try of this, equals this result and feeling completely dumb.

I hope this gives reason to the other problems.

-Tim
 
Well car is still doing the same running fine sometime and no power at others. (Same car that I drove to the Shootout w/o problems). It now also has its moments where it will hard starts. Its getting fuel for the cloud of smoke rolls out after it finally fires.

Tonight I started pulling the OE Balancer to install the BHJ SFI unit I picked up. Figure while I am there I will also install a new crank sensor as it was $15 to do so...the Crank Bolt was covered in oil when I removed it not sure if that "suggests" anything outside of a possible bad seal.

If this doesn't fix the problem, I have a new set of plugs and wires to throw in it...also a known good used coil pack.

Any other suggestions on where to hunt feel free to pass it on.

-Tim
 
A bad seal would not make your balancer bolt oily. An internal leak like a split in the hub would.

Check your fuel pressure reg and fuel pressure.
 
Installed the BHJ and new crank sensor yesterday, car fired up and runs without any sort of power issues which was nice. Found an additional problem which was when foot to the floor I was only building 7psi of boost. Found out my bypass valve wasn't bolted to the inlet plenum tightly allowing it to move a solid 2 inches in all directions.

Hopefully now that the car is running right I can start my FMIC project.

-Tim
 
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