high rpm pop

CT2500

CT2500

New member
Joined
Dec 24, 2008
Messages
158
hey guys just got my ppump conversion done pretty happy with the resaults so far. Did a little burnout yeseterday and right when the boost startes to come on iam getting this pop and then it goes away. iam going to try to upload a vid and you can see. engine is timed to 26* 160 pump 4gsk 191 rack plug modded afc. pump was put on a bech and flowed out 415cc.
http://www.youtube.com/watch?v=nPEsMWsQ8yQ
 
im no genius but im my experience , re check the timing, i too had this pop when i first p pumped it, a check and double check to the correct timing solved this. sounds about the same as my truck!
 
Thanks for the input. Whats the timing in your truck set to?
 
25-26ish on the dial but with all the variables who knows for sure, i have .084 lines and vp pop offs,so a degree or two lower is probable.hopefully thats all thats wrong but it seems similiar to mine..does it feel like it falls on its face a bit in the high rpm? mine did...not a bunch but just enough to know somethings not quite right?
 
hard to say iam not used to it yet prolly only got 30mi sence the conversion was done. when i pulled i thought it would hold higher rpm down the track left at 4k and pulled down to about 3k. when you rechecked yours how low was it? i know the pump was pinned @ 26* says it right on my fuel card, when i located TDC on the engine i made a jig that went down #1 injector hole spun engine up to it bumed it then back the other way and spilt the difference.
 
160 pumps don't fuel well above 3600 rpm so the pop could be anything from running plungers dry, momentary low lift pump pressure, etc, etc.

On my non-benched 160 pump, the more lift pump pressure, the better it runs in the 3000+ RPM range.
 
Big Blue24 said:
160 pumps don't fuel well above 3600 rpm so the pop could be anything from running plungers dry, momentary low lift pump pressure, etc, etc.

On my non-benched 160 pump, the more lift pump pressure, the better it runs in the 3000+ RPM range.
Click to expand...

i will have to check this i have to get another gauge ive got a 30psi gauge on it now and it stayed at 30psi on the line but i did notice it dropped to 25psi at the end of the track.
 
CT2500 said:
i will have to check this i have to get another gauge ive got a 30psi gauge on it now and it stayed at 30psi on the line but i did notice it dropped to 25psi at the end of the track.
Click to expand...

25psi is not enough.

For maximum power, you should be shooting for 50-60 psi.

My 95' Junker Drag Truck picked up 83HP going from low 20 psi to 45 psi. If my fuel setup would flow enough to run 55-65psi, I would because I know it would go faster. Keep in mind this is on my race truck that never goes above 3600 rpm, on your pull truck at 4000 rpm, I'm sure you are running the pump dry with just 25 psi of lift pump pressure.
 
Also keep in mind, this advice is 160 pump specific. If one of your pulling buddies tells you 25 psi is plenty they might be right for a 180 or 215 pump but dead wrong for a 160 pump.
 
whats your lift pump wired to? was it shutting off a 4k? when i had my lift pump going off the factory harness it would sound like that when the ecm would shut it off at 4k
 
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