Engine power cutting - Help!!

[TitaniumSpd]

So, recently, I've been having an issue with my power cutting out when going full (or close to full) throttle. I searched for similar issues and found a lot of people that had power cuts in the lower rpm range, around 2500rpm or so. My problem occurs higher; it cuts between about 4k to redline. When it happens, it almost feels like there is a violent shift that I'm not prepared for. The power to the wheels completely cuts for a split second, then comes right back, so I'm jolted forward, then right back from the power cut. This can happen several times before I shift to the next gear, all feeling about the same. The odd thing I've noticed is that the colder it is outside, the more prevalent the problem becomes. When it is below 20 degrees, which it has been alot here this season, the power cut can occur as soon as second gear. When it is closer to 40 degrees however, the issue usually doesn't occur until 4th or 5th gear. Lately, with the warmer weather, it hasn't occurred in about a week; but when it gets cold enough, it comes back. The car throws a CEL, usually on for about a week, then it turns itself off. It comes back on eventually, and faster if the problem comes back. A friend can read the CEL soon, but beforehand I'm trying to get some insight on what might be wrong.

I also have another question that may have something to do with it. Some piece of thick string got tangled on the drive belt while the engine was running and I was looking under the hood. While flailing about in the belt, it hooked onto a sensor and pulled it out, and eventually stalled the engine before I could cut it myself. I got the string out fine, but I don't know what the sensor is. It's the one about 4 inches below the oil cap. On my previous car, the sensor in that spot was a camshaft positioning sensor, but I'm not sure that's what this is. The thing that actually worried me is when I was putting it back in, I noticed there was oil on the prongs where you plug it into the sensor. I'm not sure if this is normal, but I remember it was the same when I replaced that plug on my old car.

Sorry for the long post, but I tried including anything I thought might be helpful. Let me know of anything else you might need to know, and thanks for any help!!!

 

[KrGsMrNKusinagi]

Sorry man if I knew more I would help you but it seems like it probably has something to do with the sensor thingy and the string

 

[USAFVMI08]

What kind of mods do you have and do you have any way to datalog?

Reason I ask is because my car was doing the same thing until A) I upgraded my fuel pump internals and B) got a custom tune at Surgeline. My car had massive boost creep which caused it to cut out after I fixed the fuel cut issue with the internals.

 

[TitaniumSpd]

Can't datalog yet, but the issue first came about shortly after putting in a downpipe and new sparkplugs. It could be boost cut but it doesnt always happen, and doesn't happen at all in warm weather which confuses me

 

[keymaster]

You have a downpipe, you need to be able to datalog. Odds are it's your fuel system cutting out, but until you can datalog you can't be sure. I'd take it easy on WOT pulls until you get a Dashhawk or whatever and can get some information on what is going on.

 

[bova80]

if you put new spark plugs in that could be the problem. are they gapped to .028? also it could be fuel cut because with a downpipe you'll probably want to get an upgraded cam driven fuel pump

 

[FORZDA 1]

You getting Max Load or Max Boost fuel cut. Common issue when people mod the DISI turbo without proper tuning. It happens more in the cold because the car makes more "load" easier. If you don't have a tuning device (AP, HT, SB) then you're just screwed.

What is the CEL code? An overboost perhaps. This is how people blow up their engines.

So your hoodie string got tangled in the accessory drive belt while you were dicking around under the hood?

That sensor is the VVT oil control valve. You will want to make sure it is repaired correctly.

 

[KrGsMrNKusinagi]

What kind of mods do you have and do you have any way to datalog?

Reason I ask is because my car was doing the same thing until A) I upgraded my fuel pump internals and B) got a custom tune at Surgeline. My car had massive boost creep which caused it to cut out after I fixed the fuel cut issue with the internals.

Mine did that till my ECU adapted.. I had bad cut etc when I did all my engine mods and exhaust mods. But after I drove it awhile the ECU adapted it does not spike like it used to 20-25 psi now it goes to 19-20 and settles back to like 15-16. Then again I guess all cars are different

 

[TitaniumSpd]

Thanks for the replies. My theory was fuel-cut from what it felt like when driving. I can get the code this weekend from a friend to make sure what the CEL is. Getting my tax return soon, and I planned on getting a cobb ap with part of the money. As far as the sensor, forzda, I figured it was the vvt sensor as that's what it was in my old toyota. I'm still wondering the oil in the plug is normal or not though. I would guess its not, but I'm not sure.

 

[FORZDA 1]

..... Getting my tax return soon, and I planned on getting a cobb ap with part of the money. ....... I'm still wondering the oil in the plug is normal or not though. I would guess its not, but I'm not sure.

Good plan to get the AP.

The oil in the plug is not "normal", but clean it with spray cleaner and see it it comes back. It could be from hamfisted oil changes/spills....

 

[TitaniumSpd]

I'll do that. Pretty sure I always get the oil in the funnel during changes but who knows. Will get the CEL asap.