17 replies to this topic

[larryo108]

Hey Rich:

I am pulling a crankshaft sensor code. I had it at one point and the car was almost undriveable. I replaced it and the car drove better, but still had a misfire type of thing going on. It was intermittent. I just replaced the sensor last night under warranty and I still get the intermittent misfire type of thing, but it is giving me the same crankshaft sensor code. I have checked to make sure that the sensor is all the way in and tight. I have cleaned the electrical connection and I can't fix this darn code.

Like I said, it feels like a misfire whenever it happens. The car stumbles and then just drives on. It does not seem to be at any certain time, just whenever it feels like it. What else do I need to look at to fix this code? What else could be setting off a crankshaft sensor code?

[Bay13]

A bad flex plate could be the problem. Look in the hole where the sensor goes, as you rotate the engine by hand, to inspect the teeth. Interfearance from wires in the area.

[larryo108]

How does a flex plate go bad? What causes that? What is the part number? What is the approximate cost for the repair? Can I do it in my garage? I would imagine that the tranny has to be dropped to perform the repair as the sensor is bolted to the top of the tranny at the back of the engine block. Please help.

[Bay13]

"Normally" it doesn't go bad, but not torqued on correctly from the start. Hot to cold rapidly, from water or such. I would verify visually before pulling the trans to replace the flex plate.

[larryo108]

Well I have had the car since 57,000 miles and it now has 160,000 miles. I would think if it was improperly torqued, the problem would have presented itself long before now.

However, the coolant line that runs from the heater core to the back of the engine just above the sensor, split and spilled it's content right around the time the first sensor was replaced. Could this have caused it?

[larryo108]

bump

[larryo108]

Alright. Driving home tonight I found that 90% of the skips happened between 2000 and 2500 RPM. But not every time I was in this RPM range. What is the flex plate? Is it just like it sounds (a plate that flexs)? Do you think it is more likely a wire interference problem or a bad flex plate. What should I be looking for to see if it is an interference problem. Maybe were a wire has broken through the loom because the plastic crumbled? Please help. I want to fix this problem before it affects something else. Thanks in advance.

[Bay13]

The flex plate is your fly wheel, only on an automatic they are called flex plates instead of fly wheels. There are teeth on the plate that the sensor counts, if the teeth are damaged, or if the plate is warpped then the counting is messed up and a code gets set. I need to spend some time in the tech notes, there might be something there about your problem. Interfearance could be from battery cable runs, other wiring, etc.

What exactly is the code thats being set?

[larryo108]

P0335 - Crankshaft Pos Sensor A Ckt Malf

Like I said, it is mostly between 2000 and 2500 RPM. Only when the car is warm. Please help. I am going to check for wire interference first. Maybe put new wiring loom wherever I can.

[larryo108]

Does the above code help you any Rich?

[Bay13]

That code converts to a EFI 131 (Volvo) Here is whats written about the speed sensor code.

The code 131 is stored if the engine control module does not receive a signal from the engine speed sensor for 10 engine revolutions.

Substitute value:
no fuel injection or ignition

Causes:
open circuit in the signal cable or ground lead
short circuit to ground or supply voltage in the signal cable
contact resistance in the terminals
defective engine speed sensor.

symptoms:
engine does not start
engine cuts out.

[larryo108]

Okay. Based on this I went back and reread my codes. Here is what I got. A lot more than just the crankshaft code.

P0335 - Crankshaft Pos Sensor A Ckt Malf
P0300 - Random/Multiple Misfire Detected
P0301 - Cylinder 1 Misfire Detected
P0302 - Cylinder 2 Misfire Detected
P0305 - Cylinder 5 Misfire Detected
P0455 - Evap Emission Control Gross Leak

I am not concerned with the Evap Emission Control code for right now. I have been trying to figure that one out for quite some time.

My ignition system. I am running an Accel Electronic Super Coil with Magnecor spark plug wires and OEM Bosch spark plugs. I am running the stock plugs because I have read they are the best for the turbo cars. I am running the other upgraded components because they needed to be replaced at the time and I figured why not upgrade.

One of my buddies was talking with someone at IPD and they said I may need more gap on the plugs to run the Accel coil. Could this be my problem? If it is an ignition problem, from what you posted Rich, it seems it could set off my Crankshaft sensor code. Please correct me if I am wrong.

If the problem could be fixed with more spark plug gap can you recommend what I should gap them to? Finally, could some upgraded plugs fix the problem?

Edited by larryo108, 01 October 2004 - 12:02 AM.

[larryo108]

Bump. Rich any ideas? Thanks.

[Bay13]

Well with all the misfires I'd start with a change in the plug gap. Stock is 28, not sure how wide the preformance guys go with this but just pick something highter, say 36 and try that and see what happens. I haven't got into the different plug game, however with my new engine I'm sure I'll be playing around. Common for most is the cheap champion copper single electrode plugs, you might want to give that a try.

[larryo108]

Thanks Rich. I'll let you know what I find.

[larryo108]

I put in some new Autolite copper plugs gapped at 35. Still doing it although it does not seem as bad. What is the highest I should gap the plugs? Is there a max gap I should consider? Also, what else should I look for that could be causing the misfires?

[Bay13]

I'm not sure about high wide to gap, maybe some of the performance guys could help here. Other causes for misfire include, wires, cap, rotor, coil. Cylinder compression and valve train "could".

[plix]

Hello Larry
I have the same code on my 98 V70 GLT (P0335) with same symptoms and I wonder if your problem has been solved and how.
Please help.
thanx.