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View Full Version : Can a bad cam sensor make it run rich?



XR7Kurt
09-17-2008, 11:40 PM
I have two things wrong, the car runs rich which fouls out the plugs and the tach works intermitantly. I know the bad tach points to the cam sensor. Can this also cause the car to run rich. I bought the car with both these happening so I don't know if both problems started at the same time.
Thanks,
Kurt

KMT
09-17-2008, 11:46 PM
Pull the codes....

XR7Kurt
09-17-2008, 11:57 PM
Pull the codes....
Codes say it's running rich...?

KMT
09-18-2008, 12:12 AM
42, 92, 137, 173, 177, 179, 182, 188, 19 (http://www.njtacc.com/tech/eec_codes.html)1...just for starters.

XR7Kurt
09-18-2008, 12:29 AM
42, 92, 137, 173, 177, 179, 182, 188, 191...just for starters.
I don't need the codes, I meant I pulled the codes and the only thing it says is that the O2 sensors say it's running rich. The ? mark meant I still needed to know if the cam sensor malfunctioning can possibly cause a rich condition. Sorry for the confusion.

KMT
09-18-2008, 12:38 AM
>meant I still needed to know if the cam sensor malfunctioning can possibly cause a rich condition

I doubt it. but hey, w/these cars...who knows either way for sure. Especially if you didn't see any codes related to the CS. Disconnect it and see...might take a few tries to get it running.

XR7Kurt
09-18-2008, 12:46 AM
Disconnect it and see...might take a few tries to get it running.
I'll try that. I think I tried that a while ago, but the plugs were probably already fouled at that point.
Thanks,
Kurt

TbirdSCFan
09-18-2008, 10:18 AM
I know the bad tach points to the cam sensor. Can this also cause the car to run rich. No. It won't.

XR7Kurt
09-18-2008, 05:49 PM
No. It won't.
Ok thanks, how about the crank sensor? I found the balancer was bad when I first started trouble shooting this problem and replaced it with a BHJ.

KMT
09-18-2008, 06:12 PM
Until/unless you are presented with specific codes indicating an issue with sensors, you may want to look for a basic mechanical issue related to running rich - vacuum/boost leaks; plugged cats; dirty air filter; mismatched/faulty injectors, incorrect sample tube, etc.

XR7Kurt
09-18-2008, 08:26 PM
Until/unless you are presented with specific codes indicating an issue with sensors, you may want to look for a basic mechanical issue related to running rich - vacuum/boost leaks; plugged cats; dirty air filter; mismatched/faulty injectors, incorrect sample tube, etc.

I've been through all that and couldn't find the problem. I'm pretty much at a dead end and since I wasn't getting codes I thought maybe it wasn't really running rich just misfiring for some reason.
I'm left with three suspect things:
1. Cam sensor due to tach problem.-Ruled out based on TbirdSCFan's response.
2. Crank sensor due to possible damage from old balancer.
3. Wrong computer due to PO replacing when he removed the EGR valve.-I haven't researched the number yet.

KMT
09-18-2008, 10:49 PM
>Crank sensor due to possible damage from old balancer.

No. It won't.

>removed the EGR valve.

What else did this gelding have removed?

decipha
09-19-2008, 05:51 PM
check the sc belt make sure its not slipping, the tensioner should have alot of tension on it

that was causing my car to run rich, 7 mechanics, over $1,000 in parts and 2 years later finally got it solved.

Tcian
09-19-2008, 06:24 PM
Yes the cam sensor can cause the car to run rich. It will not necessarly throw a code. The computer sees a value it does not like, it defaults to a rich condition to prevent detonation. While you are replacing the sensor, check the wire harnesses that you have to move out of the way. There will be one whose wire from the plug is only partually covered with a rubber hose. Tape up any exposed wire. You will see it as soon as you start to move the wires out of the way. While you are at it, make sure the vac hose running from the cold air intake to the driver's side pvc valve is attached.

Then reset your computer and check for any codes.

KMT
09-19-2008, 07:59 PM
>The computer sees a value it does not like, it defaults to a rich condition to prevent detonation.

The computer will either/or substitute a recent acceptable value from one of the lookup tables or pull the timing to avoid a lean condition. It will not enable a 'rich condition'.

TbirdSCFan
09-20-2008, 01:04 AM
Yes the cam sensor can cause the car to run rich.. I disagree. CID is not used for timing. PIP is. This is why its possible to disconnect the cam sensor all together and the engine will run just fine. A bad cam sensor will not cause the EEC to go into any protective mode.

KMT
09-20-2008, 01:22 AM
>A bad cam sensor will not cause the EEC to go into any protective mode.

Correct - as well, none of those (limp) modes would directly cause the degree of running rich/sooting up that the OP seems to indicate.

XR7Kurt
09-20-2008, 08:52 AM
What else did this gelding have removed?
I haven't found too many things removed, but there are MANY personal touches from PO.:p

sinhumane
09-21-2008, 02:39 AM
i had a rich condition, i had LEAKS.. everywhere... the egr solenoid behind the drivers side head was leaking, the t-fitting on the plenum was leaking, the egr valve had a flimsy stamped-aluminum 'gasket' that failed in all aspects of its function.... changed plugs and wires, sealed up my intake, and no more lean condition (and no more insufficient egr flow either) check the egr 'delete' he did, make sure he used a gasket, etc.... cap off your throttle body, and pressurize the intake to aobut 15psi, that should reveal any leaks you have under boost.

XR7Kurt
09-21-2008, 10:56 AM
check the egr 'delete' he did, make sure he used a gasket, etc.... cap off your throttle body
I fixed the PO's "bolt in the hole with gasket sealer" egr delete.
How do you cap off the throttle body?