Ho with mach 2 injectors pmx3 , when I am running between 20 and 30 pounds of boost the engine kinda misses and jumps around , very noticable when pulling a trailer , it did it much more when I had the smarty on , in the past when I took the smarty off it would run smooth , thot it was prolly just to much timing, but now with stock ecm , it is doing it , its not very consistent doesnt do it all the time but when it does the truck jumps and bucks around ,I have a fass pump and have good fuel presure , truck has 200 k on it and original vp , where do I start

 

is it my vp ? is there a way to test it ? some one help please!!

 

were you able to pull any codes with the key trick?

 

I've heard something about the IAT sensor causing this problem. You can take it out and clean it and see if it helps. Some people are adding a resistor with the sensor to correct the problem.

 

Which PM3 and what level?

The PM3 has a horrible defuel shutter when used with injectors. The standard seems to show it's head at level 7 and above. The Comp version level 5 and above.

As the boost stabilizes and drops, it pulls back all the fuel. Created a neck breaking shutter in my truck that was made much worse with the Smarty.

I learned to drive around it. But lower levels kept things in check.

Dave

 

its not showing any codes , its not the pmx , I have it on level 2, I know what ya mean about the pmx shuddder on higher levels, it sucks, I hope its not the vp,its been a good one so far ,but this is driving me crazy!! I will try the iat thing today

 

i thought my vp was going to last forever, i also thought vp failures was something that happend to other people...but as my sig says, i was wrong......


with 200,000 miles i would plan to change it when and where it is convenient rather than do it on the road where it might cost much more (towing to a shop that you know nothing about) good luck

 

what makes me wonder if its not a timing issue,is that it shuddered much worse with the smarty ,,, but wit da vp ya never know, is there a way to test the vp , thanks for all the help guys!!

 

cleaned my iat sensor today, I still have the miss ,not sure what to try next,any ideas??