2000 v70r mystery misfire/hesitation

Post by **JBC2565** » 04 Mar 2017, 14:29

Throttle position sensor would be my next thought.
Change the fuel relay?
Clean the ETM?

Bluevanacd2005 · Post by **Bluevanacd2005** » 04 Mar 2017, 15:17

Etm should be OK, I did the Sacer replacement a couple years ago. But that doesn't mean it doesn't need cleaning or it's not acting up. I did swap the fuel relay with a different one, I can try this again though.

Bluevanacd2005 · Post by **Bluevanacd2005** » 20 Mar 2017, 05:31

Here's the latest:

I replaced the waste gate control solenoid. Then on the test drive after, it started running absolutely terrible. It barely made it home.

I wasn't sure what was going on, but I still had the cam and crank sensors to replace. So I started that. Both looked ok, but I did notice several small pieces of metal stuck to the crank sensor. Im hoping this is the original problem of the random misfire, but time will tell.

Back to the problem at hand, I buttoned everything back up and tried to start it. It acted hydrolocked. I pulled all the plugs and turned it over. #4 cylinder wouldn't stop gushing fuel. I next pulled the fuel rail. #4 fuel injector wouldn't stop spraying fuel, even unplugged.

So I have ordered a replacement. In the mean time I will change the oil (smells like gas now) and spark plugs. Still crossing my fingers that the metal on the crank sensor was causing the random misfire.

Spenser

Bluevanacd2005 · Post by **Bluevanacd2005** » 22 Mar 2017, 10:55

I've been driving the car again for 3 days, and no sign of any misfires!

When I got home Monday, I changed the oil, filter and plugs. I put a new fuel injector in it, and fired it up. It ran rough for a minute, but cleared up. Ever since, it has been solid.

I think I can say the root cause all along was metal from the starter gear/ring gear getting stuck on the magnetic crank sensor.

Thanks for the help along the way,

Spenser

Post by **scot850** » 22 Mar 2017, 14:31

Wow, that is a weird issue if that is indeed the root cause. I'll keep this in mind when I have to tackle the misfire on my 'R'.

Neil

Post by **Clemens** » 22 Mar 2017, 16:23

@ scot850: have you replaced your O2 sensor? They only last 100.000 miles according to Bosch and as long as it isn't too bad it might not throw a CEL .

Bluevanacd2005 · Post by **Bluevanacd2005** » 24 Mar 2017, 07:24

Wow, that is a weird issue if that is indeed the root cause. I'll keep this in mind when I have to tackle the misfire on my 'R'.

Yeah, it's not hard to check. One bolt holds the crank sensor in. It's just a matter of knowing it's an issue lol.

But it's still working perfectly, so I'm 99% sure that was the issue.

Spenser

Post by **scot850** » 24 Mar 2017, 09:03

Nothing on my car is more than 8000km old (or it feels like that!). The O2 sensors were replaced with Bosch items about 2-3 years ago and are about 5000km old at most. Once I can get the car into the garage and hook Dice up to it I can see if any codes are being thrown. Waiting for replacement parking brake cable from FCP for the project so I can get it back on its wheels and they turn without binding on the Pro-Parts items!

Thanks for the suggestion though, still add it to the list of things to check!

Neil.