cps (high altitude)

[METAL MONKEY]

Were the high altitude cps units only for certain years? The dealer ship didn't have an alternate part for my 95.

Mine took a dump this morning. The last time I bought one from vatozone for around $50 it seems, but now vatozone/advanced auto want about $80, the dealership wants $127, and napa wants $110. Do these prices sound right? Also, would one be better than the other? Everyone but the dealership had one in stock, which I'm not going to buy from.

Thanks.

 

[Frank Z]

IIRC, the High Altitude CPS was only used on Renix systems and not OBD1 XJ's.

Yes the prices you got are about normal.

Try RockAuto.com or ebay

 

[eflores]

frank you are correct the high altitude CPS' were for renix years....i have one in my jeep and love it

 

[JJacobs]

No reason a guy who monkeys with metal couldn't mod his own cps!

 

[Frank Z]

True, it's simply a matter of clocking sensor. 4 deg I think.

 

[METAL MONKEY]

lol...my name actually refers to my chinese zodiac (me being asian).

So, the CKP wasn't my issue. it ohmed out fine, and I actually swapped out for a new one and still no start.

I have instructions for testing the camshaft position sensor, but I don't quite understand it. Do I take the sensor off of the distributor to test while it's still plugged in, or leave it on and test? Also, which pulley do I put a socket on to manually turn the motor over and which direction?

Thanks.

 

[METAL MONKEY]

btw...there aren't any codes being given.

 

[Frank Z]

19mm socket on the harmonic balancer bolt, turn clockwise only.

Need more info to help diagnose the problem.
Engine turns over but won't start?
Spark?
Actual fuel pressure at the fuel rail is ______PSI.
Year? Engine?

 

[METAL MONKEY]

19mm socket on the harmonic balancer bolt, turn clockwise only.

Need more info to help diagnose the problem.
Engine turns over but won't start?
Spark?
Actual fuel pressure at the fuel rail is ______PSI.
Year? Engine?

Sorry I didn't include the info earlier.

Cranks but doesn't start.
Going to check spark tonight.
Pump primes, pressure at the rail, just haven't rented a gauge from autozone yet.
'95 w/ 4.0.

The distributor cap looks good, but the rotor was in bad shape. So, I'm going to replace those tonight as well. I checked all the grounds. I'll look over the connectors tonight too.

Also, if I have to, is there another source for the camshaft sensor? Only the dealership carries it for $85 special order.

 

[Frank Z]

Pressure should be 39psi at key on, 33-34 with engine running.

Some of the parts houses call it a Stator.

 

[old_man]

Camshaft position sensor doesn't normally cause a no start. If it doesn't work, the engine computer will simply guess and it has a 50% chance of being right.

 

[xj5280]

Manual or auto? If its auto it could also be the Neutral safety switch...never replaced mine or had the problem, but i have read that a bad NSS gave a spark but no start.
Just FYI

 

[METAL MONKEY]

Manual or auto? If its auto it could also be the Neutral safety switch...never replaced mine or had the problem, but i have read that a bad NSS gave a spark but no start.
Just FYI

Thanks for the heads up, but it's a 5sp.

 

[METAL MONKEY]

So here is what I know now.

I replaced the bad rotor with no improvement. I do have a spark, and the fuel pressure is 36psi (key ON). Again all grounds and connectors look good. I don't see any kinks, leaks, etc in any lines or wires.

Thoughts?

Anyone up north able to stop by and take a peak?

 

[METAL MONKEY]

oh...just for reference NAPA calls the camshaft position sensor a "pick-up assembly". part #MP833 for about $55.

 

[Frank Z]

Time to do a compression test on all cylinders. Spec is 120-150 PSI after 3 revolutions.

 

[eflores]

the "pickup assembly" pules fuel injectors....will it run off ether or carb cleaner?

 

[METAL MONKEY]

Ether in the throttle body right? Haven't tried that.

Does vatozone have tools to rent to do a compression test, and how hard/easy is it to do?

 

[eflores]

yes, easy to do and ether in the intake yes

 

[Frank Z]

CYLINDER COMPRESSION PRESSURE TEST​

The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunctions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disconnect the ignition coil.
(5) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(6) Record the compression pressure on the 3rd
revolution. Continue the test for the remaining cylinders.
Refer to Engine Specifications for the correct​

engine compression pressures.