car is evil

[Joseph Ellis]

guys i need some help here I have a 92 SHO and shes gone crazy. Ok lets see if I can explain this, so i was driving home one evening and might i say she was performing very good, and heres where it went wrong. The next morning I got in it and tried to start it up, well it just spun and spun until finally it cranked, and spewed a bunch of black smoke. But thats not it she was idling funny spitting out the intake and stumbling and if i tried to rev the motor and it acts like its struggling to do so. Also i was sitting in it the tachometer goes crazy sometimes, for instance I had it held about 2000 rpms and all of a sudden the tach went to 6000 without any rev in the engine or input from my foot. I checked feul pressure and crank position and timing is all good, sensor is good the dis module is good the altenator voltage regulator good. i call myself being pretty good at fixing these things but this one has me stumped.

 

[sperold]

Any recent fill-ups?
Does your gas cap lock feature still function?
No issues with tank being real low or higher than you remember?
Pull the codes otherwise.

 

[luigisho]

Cam sensor? clogged cats? pull codes

Also how did you verify the DIS and other sensors are good?

 

[Joseph Ellis]

Any recent fill-ups?
Does your gas cap lock feature still function?
No issues with tank being real low or higher than you remember?
Pull the codes otherwise.

gas cap lock yes.
gas light is on but ive drove this way before.
havent checked codes check engine light not on

 

[Joseph Ellis]

Cam sensor? clogged cats? pull codes

Also how did you verify the DIS and other sensors are good?

used the end tank of intake off the 93 which runs like a top

 

[sperold]

There can be grounding problems when that end tank is disturbed (depending on which one). But I doubt if you changed that tank overnight.
Put more good gas in it, sounds like you are in a water layer. At least add some gas line antifreeze.
There can be stored codes with no light.

 

[rubydist]

If the tach is bouncing around like you describe with virtually no change in engine speed, then the cam sensor is suspect. I would unplug the cam sensor and see how it runs. (Be aware that you will likely have to crank it several times, as it has to guess which cylinder is #1 when the cam sensor is unplugged.) I have seen cases where a sick cam sensor made the engine run very poorly.

 

[Joseph Ellis]

question? is it possible for the crank sensor to be faulty and the engine still run I was thinking they either worked or didn't no in between? Correct me if I'm wrong isn't the crank sensor the only direct signal to the tach?

 

[rubydist]

crank sensor has nothing to do with the tach working - the tach works off the cam sensor.

yes, it is possible for the crank sensor to be sick - in every case of this that I have seen (several), the car would run fine cold and may die randomly once it was hot. letting the engine cool down would result in the engine running again until it got hot again. in some cases, this can go on for weeks. in other cases, it very rapidly progresses to the point where the engine does not run at all.

 

[Joseph Ellis]

crank sensor has nothing to do with the tach working - the tach works off the cam sensor.

yes, it is possible for the crank sensor to be sick - in every case of this that I have seen (several), the car would run fine cold and may die randomly once it was hot. letting the engine cool down would result in the engine running again until it got hot again. in some cases, this can go on for weeks. in other cases, it very rapidly progresses to the point where the engine does not run at all.

yes thats what was happening about 4 years ago and thats when i replaced the timing belt and water pump and its been fine until now. so i will check cam sensor when i get off work and we will see what happens

 

[luigisho]

used the end tank of intake off the 93 which runs like a top

That works for the DIS but does not describe how you know the crank sensor is good.

Cam sensor was my first guess with the tach acting funny. You can check the cam sensor by unplugging it as noted above. If that is the root cause, I would also remove it and check to see if there is a lot of oil leaking out from behind it. If so, then you should also replace the seal to keep the sensor from failing again prematurely.

 

[Joseph Ellis]

Ok guys the cam sensor unplugged car cuts off and I restarted and while unplugged the tach doesn't work at all so I plug it back up while running and boom the tach back to work. Also I don't know if I mentioned this but I can drive the car but it is weak and I mean like it will hardly rev up enough to bring in secondaries but I can cruise at 60 mph when I finally get there. So does anybody have a description of voltages and ohms that these sensors are supposed to be

 

[luigisho]

Did you pull the stored codes? That's job 1 here. Makes it less like shooting in the dark. http://web.archive.org/web/20070518111620/http://www.shophoenixproject.com/eec/eec.htm

You can have plenty stored in the pcm memory without a check engine light staring at you. We don't make this stuff up.

The cam sensor is used to read the rpm at the tach. That's why when the tach goes crazy and doesn't look like it matches engine rpm the sensor is suspect. Choked off power can be a lot of things. I would usually look at the maf for loss of power and screwing up the air:fuel mixture or vacuum leaks or lots of other stuff.

 

[rubydist]

if you re-read post #7, it does not say anything about unplugging the cam sensor while the car is running - that is a recipe for disaster. Unplug the cam sensor, start the car (it may take several cranking attempts) and then drive it and tell us if it acts the same or not. (We know the tach will not work, that is not news.) We are attempting to help you narrow down the range of suspects - you can work with us and we can help you, or you can keep doing your own thing and then we cannot help you - the choice is yours.

 

[Joseph Ellis]

if you re-read post #7, it does not say anything about unplugging the cam sensor while the car is running - that is a recipe for disaster. Unplug the cam sensor, start the car (it may take several cranking attempts) and then drive it and tell us if it acts the same or not. (We know the tach will not work, that is not news.) We are attempting to help you narrow down the range of suspects - you can work with us and we can help you, or you can keep doing your own thing and then we cannot help you - the choice is yours.

Ok I unplugged the sensor then cranked the car and drove around the block and no difference. Also I don't know if it matters but I did unplug the mass air meter (before I asked you guys for help) and the car doesn't really react at all. But I did pull some codes and with the koer I pulled 159,136,213,411,538 the koeo test gave me some numbers I didn't find on the list. Trust me I want to work with y'all cause I'm at a loss here!

 

[luigisho]

Some of these are recognizing that you unplugged the maf sensor, failed to do the goose test and other things that shouldn't really matter. The o2 sensor could be faulty but it often gets triggered when other systems are faulty and mess up the air:fuel mix. I would clear the stored codes, run it again and see what pops back. I don't think the SPOUT code would get triggered by not running the cam sensor but I'm not sure about that.
If the SPOUT code comes back, then usually the error comes from the DIS or computer or wiring somewhere in there. DIS first to check with that. Clear it out and run it again.

 

[rubydist]

Thank you, that was helpful.

Please plug in the mafs, leave the cam sensor disconnected, clear the codes, and run it again and see what codes pop up, and report those back to us. We need to make sure the "spout" code and the "cannot control idle" code get cleared up, because it will not run right with those codes.

 

[Joseph Ellis]

Ok here's the new codes I got after clearing everything trying again. With the koeo I retrieved 111 & 121 and that's it, with the koer I retrieved 136,159,536,538 and that's all. Again thanks for all guys help in advance.

 

[luigisho]

Now unplugging the MAF sensor will throw a MAF code. Did you clear all the stored codes before you ran this latest test? Throttle position sensor, MAF and O2 sensor failures will throw off air:fuel calibrations and cause it to run poorly.

 

[Joseph Ellis]

Yes sir I did I had battery unhooked for a couple of days and hooked it back up andcranked it and brought it up to temp and rescanned