Mongo

I should have replaced it when I did the intake service as I saw it pretty crispy looking in the back of the car, but I didn't.

Now, I have been having a bouncing tachometer on startup/cranking. A couple days ago, it felt like I hit the rev limiter at 4,500 RPM, now I have a hard time starting the car both warm and cold. I have replaced the majority of components in my fuel system with the exception of the dampers (which are still functioning fine to my knowledge).

I found a crank sensor for cheap, but don't want to jump on it until I know for sure that's what's causing my symptoms. Any ideas?

Lizard928

If yours wasn't looking that good replace it. Cps failures are normally hard starting or no spark. But they normally show up as intermitant issues to start.

Mrmerlin

add a bottle of techron to the fuel.
get a fuel pressure gauge on the rail
find out when the LH was rebuilt
run the car at night and look for sparks coming from the ignition wires,
remove both coil wires and check the ends

Mongo

New wires already done, coil wires too and connectors were cleaned really good (Roger's wires BTW). I use Techron all the time too. Car was running fine up until the last week or 2.


Oh and that 4500 RPM surge was definitely intermittent. It hasn't done it again.

Mrmerlin

replace the CPS

dr bob

^^^ What Stan says.

Andy--

You know the part is already crispy and you are on borrowed time. So it's a matter of 'when' not if it's going to give you serious trouble. Do it now to eliminate the possibility, avoid getting stranded someplace where changing it isn't so convenient. (side of the road in the rain snaps to mind...) No need to gamble. IMHO. Plus it is a very possible cause of your problem.

Mongo

Will do. At $50 for the cross-referenced Bosch part #0 261 210 002, I can't lose.

mj1pate

My CPS harness connector fell apart in my hands and that was enough for me. I know of others who have patched their harness back together and drove on. But the fact is that the bonding between the electrical conductor and the pickup can fail. The CPS is high on the list of components that when flaky, will indiscriminately stop you cold. Don't make "cheap" a qualifier for buying a replacement. Buy one from a known good source. For practicality sake, if you're in there doing fuel line or intake work and don't know the history of the existing CPS, then replace it.

Mongo

HELP!

Big Time Surge this time at 4500 RPM. Violent enough to feel like the car stopped dead at 4500 RPM. Flappy is opening alright. Still intermittent. The second and third WOT downshifts accelerated fine. Is this ignition related or could this be an auto transmission issue...the car shifts fine BTW.

If Ignition/Fuel, I have replaced:

-Fuel Pressure Reglator
-Spark Plugs
-Ignition Wires
-Fuel Pump Check Valve
-TPS
-Intake Manifold Vacuum Lines
-Flappy Solenoid
-BRAND NEW INJECTORS
-Idle Stabilizer Valve
-MAF
-Oxygen Sensor 10,000 miles ago
-Fuel Filter


I don't know what else it could be. Again my crank sensor is old, it has a hard time starting every now and then, and I don't remember when the coils were ever changed as the look original.

Could this really be the crank sensor or something serious elsewhere?

AO

Could also be a gound issuse. Check your grounds - especially since you've been "in there" recently. In particular, check the two grounds at the rear of the intake for the harness. If either is loose, it can cause the injectors to not fire. Basically it will have the same symptoms as a bad CPS except that it's the fuel being cut off, not the ignition.

Lizard928

replace the CPS first and see if problem happens again.

Mongo

Buying a crank sensor now.... Will check the grounds back there when it comes in and start sanding connections down again.

Ben Allison

Is it repeatable (i.e. does it always happen @ 4500 when you repeat the steps). I had a problem very similar to this on a different car with a dying battery, before.

Tom. M

I'm guessing brain issues....find a spare brain to test in your car (LH first)..then ezk....

mj1pate

Stay close to the basics at first. After several stall-outs and agonizing tows, I was considering swapping out the ECU modules for after market. Then I finally checked that second power bus connection at the battery (the "loose" connection that powered the ECUs). That was 2 years ago and the ECUs have been happy since.