TST PM3 Comp upgrade....with problems

JFlagg

JFlagg

Gun for Hire
Joined
Jul 27, 2007
Messages
5,630
I just sent my PM3 out and got the software changed to the competition tune while I was in Jamaica. I hooked it up last night but didn't get to try it till I drove to work this morning. The good news is it fuels great past 3000 RPMs, bad news is it cuts out and shudders real bad under throttle. I've only been able to get up around 2900-3K twice. It even shook so bad once it almost pulled the shift lever out of my hand! Is there anyone else out there with this box and upgrade that has had this problem? Its not just limited to the upper RPMs either, it has done it at partial throttle around 2100 RPMs also. It also has a loud crackling sound I can hear out the exhaust. Is it a software problem, or do I need to upgrade something else now to fix this?
 
The only time mine shudders is when I back off the throttle on the upper levels or if I'm trying to part throttle cruise on the upper levels. Other than that it's just a smooth, seamless onslaught of power. Well, as big an onslaught that can be had with rv275's. LOL

It might also be your VP getting weak and not being able to put up with it. I'd go and make suure that all the connections are good and solid.
 
"Under Throttle" should be smooth.

Levels 1 through 5 should be smooth when releasing the throttle
Levels 6 through 9 can get a de-fuel shudder when releasing the throttle.

It might be worth checking the fit of all connectors to ensure they are tight.
 
BgBlDodge, beat me to it! :bow:

And brings up a good point. If you're running out of fuel; either from VP failure or supply, you can get shudder problems. Still, not "usually" too harsh though.
 
I thought about maybe not getting enough fuel, but my Ind. Inj. HRVP44 and FASS 150 should be giving me plenty. I only have 60HP sticks though, but that shouldn't be a problem. As far a "defueling" shudder, I've learned how to easy off the pedal to keep it from doing that too (also easier on the turbo). I haven't gone through all the connections yet, thats for after work. Just wondering if there was a problem I might be missing. Other than the bad shudder/crackling sound, it pulls like a beast past the 2700-2800 limit it had before. I just wasn't sure if it was software or hardware giving me this problem. Thanks guys!

PS. I'm keeping a solid 15 psi at full throttle also, from 18 psi at idle. So, it shouldn't be lack of fuel.
 
Just cause you have a HRVP doesn't mean that you could be running outta fuel. When we say running out of fuel we mean that your vp might be getting weak and not being able to keep up with the demand.
 
while your under throttle and its cutting out, watch the green light on your box. if the green light cuts in and out, then you either have a bad connection where the fuse is on the harness or you dont have a good connection on the wire tap on the pump. its really really sensitive. i had the same problem as you and unplugged it from the VP and back in and it solved the problem . make sure you have a good connection in both placses. if it stubbles and the green light never misses a beat, then you got a problem like blue stated with lack of fuel
 
Thanks, I'll watch my light tonight on my way home and see what it does.
 
where are you getting your ground at?...mark suggests getting it from the ground in the loom,not battery direct...just another thought......bama
 
Thanks guys, I checked all my connections(cleaned and regreased them) and everything works perfect now:D I should have checked that first, but being at work on the computer, it was easier to ask since I couldn't just go work on my truck. Now I have nice smooth power past redline:D
 
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