Hello everyone,

I'm new here and looking for some advice from the experts. My dad gave me his 1992 Park Ave Ultra and I'm trying to decide to fix it and keep it or sell it. The car only has 106k on it and has had thousands in repairs over the past couple years. But there is one problem that I can't seem to diagnose...

She runs strong and smooth when the engine is hot, but when it'* cold the idle is erratic, the tach needle actually jumps, and the engine misses. The SES light comes on and it reads code 18 (Cam/Crank Sensor) when you use the jumper.

Has anyone here experienced something similar? In my trouble shooting I've done all the basic tune up stuff, replaced the TPS because it had a bad spot when I put it to the Ohm meter. I replace the IAC, which was probably a waste of $80. So, I've dumped a couple hundred bucks into and don't really want to spend a whole lot more. What should I expect to get if I sell it? The NADA, Edmunds and KBB range from 1500-4000 depending on condition.

Any advice is much apprciated, I'm hoping its not the cam sensor magnet that has come loose!

Thanks,
-Andrew

if it was me i would get the Code 18 problem fixed as it seems that is the problem you are having with the car....

also if it was me i would drive the car instead of selling it, because of the low miles that are on the vehicle

I've spent a lot of time thinking, tinkering and searching the web for the cam/crank sensor error. So far, can't pinpoint it. Thanks in advance for the help!

Any thoughts on this problem? From what I've read, the fact that the car is getting normal gas mileage and runs perfectly when hot would indicate that the magnet is still in the cam gear. Thanks!

Can you give us more info on what'* happening when the ' tach needle actually jumps'.

Only when cold, the engine runs poorly. The the tach jumps at the same time the engine misses. Sometimes the jump on the tach is 300-400 rmp. The tach will also twitch a little, but you won't necessarily feel a miss from the engine.

If you start the car cold, it revs high. About 1600-1700 rmp. The cold idle rmp will also jump and eventually throw the SES code 18. Before taking things apart to access the Cam and Crank sensors, is there something more simple I should check? Is there a way to tell if the Cam sensor magnet has come broken off without pulling out the Cam sensor?

Once the engine is hot, it runs like a champ. The SES light will stay off if you turn the car off and re-start it hot. Thanks!

If you're saying the tach is jumping up 300 rpm while the engine speed is dropping or remaining constant then that would seem to point towards the crank sensor being bad.

If both the engine & tach are jumping 300 rpm then I'd look at other things. Do you have a multimeter?

Check your grounds at the ICM. IIRC, both the crank and cam sensors share the same ground, and that ground is at the ICM bracket. Since both sensor also go into the ICM itself, I would *also* check the ICM connector for corrosion or bared/shorted wires. And it wouldn't be a bad idea, while you are there, to take the coils off the ICM plate and check for corrosion and dirt under the coils.

Thanks for the tips, I'll check the gounds and connections before I replace sensors. Can some one point me to the ICM?