I broke something, how do I figure it out?

Well, I was feeling cocky today...

Car is 89 tbird sc, 5 speed, has 102k miles on it...

I went to turn onto a back road, and dropped it from 1st to 2nd. I then procedded to rail on the gas, and give it 5k b4 each shift.

I got to 4th, and the shift light started to flicker, the tach was at 3kish. Then, my tach went bazerk.

I went to grab 5th, and the car started lunging, hard. I gimped it home, trying not to go over 2k, at 2kish, it would start to lunge and make a pop sound in the exhaust.

I noticed the temp guage went up, usually it does not do this. I turned the heat on high, and, it went down promptly.

I just replaced the crank sensor, an sc friend of mine says crank sensor or harmonic blancer by the sound of it.

I think it is something with the ignition, the way it pings and pops, and has the lunging.

I check my coolant and my oil, both are fine.

Any way to check the crank sensor or anytihng else w/o having to remove anyithng? Any way to test it with a dmm?

Any one else got some suggestions?

May be the Cam Sensor.... (much easier fix than the crank sensor and a little cheaper, too.)
If you can get your hands on a code reader, that would be helpful...Most autoparts stores have cheap units available for around $25 - $30....

LJGriggs said:

May be the Cam Sensor.... (much easier fix than the crank sensor and a little cheaper, too.)
If you can get your hands on a code reader, that would be helpful...Most autoparts stores have cheap units available for around $25 - $30....

Click to expand...

k, I will try to get my hands on one of them and see what it says.

David

Will it idle...did it throw a CE light ? Did you pull the balancer when changing the crank sensor ?

I'm betting it's the dampner and crank sensor too. Mine had the same symptoms your describing when the DIS module went bad, but revving the engine high shouldn't have any effect on the DIS module, but it would put more stress on the balancer/dampener.

David

sounds like damper mine just broke a month ago it ran warm and no power at all , i think it would still idle slow but it rev real slow like late on timing

Trust me pull the bolt out ,if it is still there,of the balancer and tug on it bet it falls out in two pieces!

I didn't pull the balancer, but, I will try to take the bolt out.

Auto Zone

Auto zone reads codes for free, But doesnt sound like a sensor problem ,,sounds more mechanical,,Float a valve or bent a push rod maybe???
good luck Vetteman



89 SC
76 vette
84 vette
87vette
70 GT torino

Well, today b4 I decided to tear into anything, I checked the oil and seen that it was low. So, I went to the gas station and got some oil and some gas, I put in some gas, and then drove it around town, and when it was warmed up, I got on it a little bit, I noticed at times, it would hesitate when I would push on the gas, and then go, I also noticed the idle at times, is very smooth, no misses or anything, and then at other times, it is very rough.

I drove around town, leaving it in a lower gear to hold the revs at 2500-3k, it was very smooth, did not make any pinging sounds or lunging, until right b4 I came home, I went to grab anohter gear, and b4 I let off the gas to push the clutch, it lunged like it was doing b4, but, did not make any pinging or crackling sounds b4.

The crank pulley seems very solid, I had no issues with the shift light or weird tach today.

Someone above mentioned that they had simular problems and then they replaced the DIS module. Right now, I do not have the cash to play with the harmonic balancer, or, I would have simply replaced it as I had wanted to when I did the crank sensor....

I got 0 cel lights, no upshift light stuck on, I was told that any time the shift light comes on when it should not it is the crank sensor.

It did the lunge thing it did b4 when the car was heated up, so, the only thing I can think of is something is getting affected by the heat?

I am going to buy a cam sensor from charky and see if that helps at all...

if the upshift light comes on and stays on its the cam sensor. I see mine in 4th when I race.

Scott Long said:

if the upshift light comes on and stays on its the cam sensor. I see mine in 4th when I race.

Click to expand...

Yeah mine came on in 4th...it was flickering when I went from 3rd to 4th, never steady though...then the tach went nutz and the car started making a weaird pinging sound over 2k and would lunge.

Like I said, I am going to try a diff cam sensor, charky is also sending me a coil pakc and a DIS module if he has theold style around