06 Tacoma 4.0 Crank positioning sensor ?

Ok, went to work yesterday I noticed my truck running a little rough, when I stepped on it ,it seem to clear. Was going to tune it up payday. Went to start it today , sounded like it was going to start ,then it sounded like half way through it lost compression or spark , tried it again, same thing half way through. Now it sounds like the loss of comp. Or spark every time I try an start it. I need help it's my only vehicle.could this be the crank positioning sensor, if so, how would I test for that ?

 

Before condemning the Crankshaft Position Sensor(CPS), I would look at a few other things first:

- Is your battery healthy
- Air Filter clean
- Mass Air Flow Sensor Clean
- Spark Plugs Fresh
- What about stored codes. Have you hooked up a scanner

Because you have an '06 6 cyl engine, some may chime in and blame your problem on a blown head gasket. I would look elsewhere first. Lots of obsessing goes on here over blown HGs.

Here's some factory service manual info to look at. Lots of things beside the CPS could be involved:

http://www.customtacos.com/tech.old/files/05FSM/repair.html

 

No, I'm still trying to find someone I know who has a scanner. Probably going to have to wait till Friday and buy one on payday. That link you posted , showed a way to check some of the sensors with a volt meter. It'll at least give me something to do until I get a scanner. Thanks for your info

 

Any love on this? What did ya find out? Im having the same thing happen. But I’ve already replaced the CPS. Still same issue.

 

So what codes were pulled?

 

P0335-crankshaft position sensor is all mine has. Some days it refuses to run. It’ll try to start for then die instantly.

About 6 weeks ago it had a head gasket job and new timing chain. It ran fine up until last week. Then started this shit. The first codes came up for the MAF sensor. I cleaned that. Then next day it started with the crank sensor. And I’ve been trying to figure this out since. I replaced the crank sensor and throttle body. Nothing fixed. I was already planning to replace throttle body for other reasons. But still didn’t fix anything.

 

Below I've posted the P0335-P0339 code info from an '05 factory service manual. You may have seen it. Sounds like an Oscilloscope would be needed to debug and that won't be of any use unless you have a "Failed" condition. Further into the PDF you'll see a comment about checking engine mechanical if all of the preceding testing failed to uncover.
anything, hence the reason for my quote.

 

Greatly appreciate that! Im gonna need to call in some help to do those tests. Im beating my head against the wall on this one. As I’ve only been stumped for weeks on In like this once before. And that was a loose ground wire coming from the ECM on an old dodge neon. Lol.

Lemme start from the beginning. About 2 weeks ago it started running funny and the light came on. The codes were p0302, p 0102, and P0113. The wife drove the truck on home. But when she got home it would start then die immediately. So I took the MAF sensor out and cleaned it. It started and ran but now the crank position sensor code came up. She drove it out on an errand and the light went away. But the next morning it would not run again and the light came back for crank sensor. I replaced the crank sensor and nothing. I spoke to a friend of mine and he said to unplug the MAF sensor and see if it starts. Well by mistake, I unplugged the Throttle Body, but the truck did start and run. I plugged the Throttle body back in and tried the MAF sensor and it would not start. So we kinda assumed maybe one of the sensors in the throttle body was causing it, so I replaced it (the throttle body). It was filthy and has 270k on it. Since the engine was recently overhauled, I decided to just replace it as well instead of cleaning it. After I replaced the Throttle body, it started and ran. The first 30 seconds or so was kinda rough. And I assume that was Bc it was adjusting and taking readings for the new part. But it smoothed out pretty quick and ran fine, yet the crank sensor light is still on.

Yesterday the wife drove it to work and during the day the light went off by itself. It ran fine this morning with no light. She leaves for lunch today and the light comes back on. She says it’s runing fine. But this will be the 3rd time of this. And I’m worried it’s not gonna start/run later tonight or in the morning if this time goes like the past couple weeks. Im seriously at a loss! Lol. Im not gonna Say I’m the best mechanic ever or anything. But I’ve been doing this 30+ years and never seen one quite like this before.

 

After a long battle with this Tacoma I changed out the crank sensor , sure enough fired right up. After a day or 2 it started throwing crank positioning sensor code again and idle was rough, now it runs for a while and dies , takes some doing to get it started again only to repeat the same actions. Does anyone have any clue ? Computer brain? Cam sensor ? Help please

 

Ever find out what this was?? Mine is doing something similar to this

 

Yes I did , rhe sensor I bought wasn't OEM . cheap ebay one, I bought a OEM certified one and it runs fine . if I was you , I'd check the cam sensors first, cheaper and easier to get too. Good luck