ok just installed some jammer stage 3's in the truck (nozzles). but I didnt have them pop tested....closest place i can find is in waco (2 hrs away). first four times it was hard to crank, but now seems to crank just as usual. however the "rough" idling has not gone away. This "rough" is not very bad in my oppinion but is noticable, just a very slight jumping of the rpm guage but i really notice the audio....sounds like it jumps and falls every half second or so. i put the injectors in today and put 100 miles on it right away, perhaps i should wait and see if things smooth out? is this common with new injectors? will pop testing do me any good? oh yea... pulled the codes a min ago and still have the same P1693 ip pump code that i have had for the past 40,000 miles....hasnt died yet.
thanks in advance for all your ideas/commments/scorns.

 

Did u try bleeding the injector lines?

 

after putting everything back together, i bled 1,3,and4 (easiest to get to) in order to get the thing to crank.
oh yea while i was in there i did a valve adjustment........maybe that is my problem?

 

BUMP.....same story today. any recomendations?
thanks

 

Could a bubble of air still be in one of the lines not bled?? Can't imagine so after a 100 miles of driving thoguh

 

maybe another clue.......or perhaps normal for the large injectors. almost "too much" throttle response. its kinda tough to drive this thing nice and easy. a little pressure on the pedal and i get there dern quick. a little uncomfortable to drive at slow speeds around parking lots etc. this problem remains after i reset the APPS last nite. (perhaps a slight improvement after the reset)
thanks teddy bear and bnold

 

if you just put the nozzles in then that might be the problem. Pop testing is a good way to get the pressures set the same. It sets them all to the same pop off pressure. if one or two are opening to soon or to late that will cause a rough idle. I put rv275's in mine and only ran the lift pump 3 times and it fired right up on the first time and smoothed out after about five minutes of idling. I replaced the whole injector not just the nozzles.

 

I'll throw my experience in.

My old 2001 truck ran smooth stock. Ran smooth with DD2 honed injectors.

Then I upgraded to Jammer 4's. I installed the tips myself and had them popped. Got the truck running as usual but had that "rough" idle.

Pulled the sticks and had them re-popped by another shop. This time again, all were within 2 bar or so.

Put them back in and had the same "rough" idle.

Pulled them out, and buddy put them in his truck and they ran fairly smooth so he bought them from me. Then I went ahead and got a set of Supermentals that I got a good deal on. Guess what, I had the same rough idle.

I had assumed that my pump with 117k on it was getting weaker. The stockers that I was putting in between injector changes pop tested almost 10% below the proper 305 bar. So maybe the new injectors were set up at 305 bar and my pump was having trouble firing them consistently.

Under load I never noticed any miss or stumble. Just at idle in neutral.

My truck had a rought idle for 60k miles it it never got any worse so I never fixed it.

Jason

 

thanks guys.......thats a very interesting post jstull.....i do remember having a slight idle problem in nuetral with stock as well, i just thought the injectors were the prob........but now that u mention it that makes a lot of sense. perhaps the pump is gonna give sometime soon. are the new injectors gonna hurt my pump life much?
thanks a lot

 

I think the injectors will only hurt your pump if you let the fuel pressure get too low. If you keep the fuel flowing then it should be fine.

Jamie