when i get into my throttle hard i get a horrible popping noise, i think out the exuast. I cant figure out what it is doing. I pulled the truck last season and it has never done it on the sled. just at high rpms, to the floor on the high way. any ideas?

 

Fuel filter, your draining the rail, or something. My truck did it once before when I had a bad fuel filter. In the high rpms it wouldn't let enough fuel through and would make a loud pop out the exhaust.

 

I just put an airdog system on my truck, I thought it would get rid of the popping noise. but it hasnt, it still does it with good filters. if you know anything else or know someone who can give me an answer, let me know. thanks!

 

Sounds like you are draining the rail. Do you have a rail pressure gauge?

 

What year is your truck and what have you done to modify the CP3? A LP doesn't cut it if your fueling heavy w/ stock Cp3.

 

my truck is an 03, my outlook monitor has a rail pressure guage. it seems to stay around 24-26 in the throttle hard. i will check today to make sure. I was talking to some guys about my cp3, and they said if it had yellow and green marks on the pump it is a modified pump. I think with the propane on it does it worse, the popping noise. it popping noise is like as fast as a machine gun if that makes sense. someone told me the head gasket was acually lifting on their truck and made a noise like this. any ideas? thanks!

 

mine will pop like this sometimes i believe it is lack of rail pressure.

danny

 

Mine does the same thing with the TNT tunes only, I have really good railpressure so thats not it on mine.

 

You are hitting the rev limiter. I do it all the time with my truck on the highway and it will only do it on the pull track in 2nd gear (auto).

I just did it saturday night when I left OD locked out a little too long racing my buddy.

 

these trucks dont have a rev limiter they have a governor and it doesnt work like the gas vehicles where it goes up and down it just stays at one constant rpm so that should not be causing the pop it may be that you have got the rpm up so high that it has started to defuel the motor and then causes the rail to drain leaving you with low rail pressure causing the motor to fire improperly. that is my 2 cents. atleast this make sense to me i could be completely wrong though.

 

I always thought it had a rev limiter because of what BD sold me. I was told it would do away with the speed limiter, defuel for tranny and rev limiter. It never worked right and I took it off. So I guess the truck doesnt have a rev limiter.

 

He says it gets worse with the propane and only happens in upper RPM's at WOT... that is a indication of too much timing. I would bet money on it.

However, that said, the other problem would be the cp3-- either it is not a modified one to handle the extra fueling from his crazy larry/torque dog stack or it is simply crapping out from wear. I mention this as a secondary cause as he reports maintaining good rail pressure from his outlook monitor.

 

i would say to much timing, on my smarty if i run anything more than timing set on 2 on revo i get bad popping.

 

What does the boost gauge read when this happens?

 

i havent watched the boost, but i did some research, and im going to borrow a compression tester, and check compression. I have been hearing guys having the valve seats come loose from the head, do to getting the egt's to high. they say on a common rail it happens when you go over 1300. I have seen 1640 on my pyro. so im gonna look that route, im not sure if I want to find a problem there or not! thanks for all the info, i will post on here what i find out.