Welcome to www.JeepStrokers.com!!
Not yet a registered user? You are required to Register before you can post within this topic.

4.7 Stroker has developed a MISFIRE

For all non stroker / performance related problems and discussion.
Post Reply
BcurpKodiak
Making Progress
Making Progress
Posts: 75
Joined: November 2nd, 2015, 8:12 pm
Vehicle Year: 1997
Vehicle Make: Jeep
Vehicle Model: XJ

4.7 Stroker has developed a MISFIRE

Post by BcurpKodiak » August 3rd, 2018, 9:43 pm

Hey y'all, gotz a problem with meeee stroker!

Thing has been running great, tons of power. One day after a trail ride it developed what I believe to be a misfire on the way home.

It happens around 4000 rpm. It was really inconsistent at first, but now it's fairly consistent when it happens, and now it happens in all gears as well.

I'll floor it, accelerate hard and it misfires pretty bad. It idles fine. Power from 1000-4000 is still excellent.

-New plugs that Ryan at FRP told me to run BKR7E/4644 along with the DUI firepower ignition setup.
-New CPS from NAPA went in during stroker install
-New coolant temp sensor (just because I broke the old one, this is not all due to troubleshooting)
-New primary Oxygen sensor (had it on hand in case it shit the bed, so I went ahead and threw it in, didn't change anything)
-New Cam position sensor
-New fuel pump, old one made 46 psi, fuel level gauge was funky and bounced around. Installed new one (bosch from Napa) and confirmed I now have 49 psi.

I have had some issues with PCV and blowing my oil cap off. I turn over 6000 rpm and I don't do that every shift, but plenty hahaha. So I came up with a sorta/almost catch can setup to help keep motor oil out of the intake (I was getting quite a bit in there).

So could it be the new CPS? Some things point to that including Ryan who's tuning my Jeep. It just came in the typical NAPA box. It sure was expensive though

Sensors I have NOT replaced:
-Intake temp
-TPS
-MAP
-IAC

Any ideas?

I6FAN
I made it to triple digits!
I made it to triple digits!
Posts: 148
Joined: March 28th, 2010, 9:31 am
Stroker Displacement: 4.2
Vehicle Year: 1987
Vehicle Make: jeep
Vehicle Model: wrangler

Re: 4.7 Stroker has developed a MISFIRE

Post by I6FAN » August 4th, 2018, 10:56 am

My guess is ignition. Had a Honda a few years ago with a bad stumble around 2300 rpms. Would idle fine, sometimes accelerate okay past the 2300 point if I did it smoothly (not always). Anyway, threw all kinds of sensors and money at it (some were needed anyway). Couldn't ever figure it out until I pulled the rotor off, and noticed the end of the shaft with a pinhole arc burn. Looked at the inside of the rotor, and discovered the culprit. I over thought it completely; just the basics would have fixed it. If you have another ignition you can swap on it I would start there. Good Luck!

BcurpKodiak
Making Progress
Making Progress
Posts: 75
Joined: November 2nd, 2015, 8:12 pm
Vehicle Year: 1997
Vehicle Make: Jeep
Vehicle Model: XJ

Re: 4.7 Stroker has developed a MISFIRE

Post by BcurpKodiak » August 5th, 2018, 5:31 pm

Yea it has an aftermarket ignition setup on it. Had to pull the cap recently to replace the cam position sensor and got a look inside. Everything looked fine.

BcurpKodiak
Making Progress
Making Progress
Posts: 75
Joined: November 2nd, 2015, 8:12 pm
Vehicle Year: 1997
Vehicle Make: Jeep
Vehicle Model: XJ

Re: 4.7 Stroker has developed a MISFIRE

Post by BcurpKodiak » August 9th, 2018, 12:03 pm

My intake manifold bolts were loose. One fell all the way out. #6 spark plug was dark and didn't look like the rest. Buttoned it all up with new plugs and it runs like a raped ape again.

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest