A friend's 01 Chrysler LHS had a cam position sensor failure today. It almost quit running completely. We replaced the CPS (auto zone brand) (and what a paint to get out). Anyway, it's now hard to start and he says the throttle feels like it's stiff sometimes. It is still reading CPS failure with my scan tool. Ideas? It's his only car so he is a bit desperate to get this figured out. Thanks!!
I also scanned it running and the timing is hunting by several degrees. It's going up and down. When he's trying to start it you can sorta hear it. It used to start right away until this happened.
Crank sensor is erratic, but not erratic enough for the ecu to be correct on it's diagnosis? CKP is not even remotely uncommon.
Or, is the cam sensor correct, but the cam timing is actually wrong?
Which engine? 3.5 has a belt...
It has the 3.5. It wasn't having any problems until yesterday.
In reply to markwemple :
Maybe nothing was broken until yesterday...
No starts are easy. It's either lacking fuel, spark, or compression on several cylinders. Fuel is easiest to test for. Spray something flammable in the intake tract and crank it. If it acts exactly the same, it's not a lack of fuel. Checking spark is a little harder depending on the car and what you have on you. If it has fuel and spark, it could either be sparking at the wrong time, or have lost compression on several cylinders (one dead cylinder won't keep it from starting, and two probably won't either on a 6cyl). A 'jumped' timing belt can cause both of those issues so if it has fuel and spark i would probably verify the timing marks. On old chryslers there is a datastream item called 'sync' that will show NO while cranking if the cam and crank position sensors aren't correlating as they should.
Throttle being stiff is either the cable or the throttle shaft bushings on the throttle body, and not related to the no-start. Even a car with a stuck-shut throttle will still start unless the throttle body is massively dirty AND the idle motor is restricted or stuck closed. Tall odds..
Hmmm. If memory serves, the cam sensors had spacers. Did your AutoZone unit come with a non conductive spacer? Glossed paper or plastic ring. Something not too dense.
Can't remember the fastener methodology for that one. Too far back.
Stiff throttle is weird. Most likely cause is someone bent something during cam sensor install.
There was no spacer on the old one. They bolt on from the side so height is not adjustable. He can drive it but it isn't running right. It takes 10 seconds or so to start instead of 1 or 2.
It is right up front of the car right?
I asked a fellow former Chrysler Engineer and he says it could be the harness wires finally giving up. But to first just try to replace the highest quality Cam Position sensor you can get. Make sure no metallic debris is left in the hole.
The spacer thing may be me remembering a development part instead of the production parts. Sorry.
In reply to Vigo :
I'm on the jumped time bandwagon. Common symptoms. On Honda's chain engine (K) cam sensor issues are usually stretched chains and worn out tensioners and not the actual sensor themselves.
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