Bouncing timing marks

[Trying my best]

I was checking the timing on my buddys truck with the ferret adaptor and it looked like the marks were not landing in the same spot every time. It also sounded like the motor had a slight miss. It's a new promar with new typ 4 injectors and a questionable injection pump. Do y'all have any idea what might cause this?

 

[franklin2]

I read another post where if you fiddle with the position of the pickup on the line, it can help that problem. Also do a search or someone will write in that knows, but there is another cylinder injector line you can clamp to that will give you the same correct timing reading. I think it's the line that is normally used on some of the vans.

 

[Clayton]

Yes you can test on the number 4 cylinder. Make sure you sand the line clean and the ground has a good connection.

 

[Trying my best]

Right on I'll try to sand the grime off the line and see what happens.

 

[icanfixall]

Did you use a magnetic probe at the crank and did you clean out the dirt and oils in the probe location.... A 5/16 drill bit rolled between the fingers will clean out the crap. Then spray out whats left with brake clean or anything else thats good for cleaning out road grime..

 

[Trying my best]

I used the piezo clamp on the number one injector. The engine felt like it had a miss to it and didn't know if the bouncing timing marks and the miss were related

 

[icanfixall]

The bouncing timing, possible bad injection upm or bad injector could all be an issue. Try the number 4 injector. If the bounc continues then its possibliy the pump. How many miles are on the pump. If its over 125,000 miles is done so a rebuilt pump is needed.

 

[Trying my best]

Sounds like a plan, thanks. Then injection pump is defiantly of unknown age, so that might be the problem.