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Engine Specific Info and Questions => IDI Engine => Topic started by: oldskool rich on April 09, 2008, 03:35:56 pm

Title: aaz under fueling, has anyone heard of this?
Post by: oldskool rich on April 09, 2008, 03:35:56 pm
ok i believe ive found the cause of my stalling trouble, my local vw specialist told me that its definatly not mechanical, and so it has to be down to fuel.

my pump is a bit nutty, boost pin is extreamly modified, also 11mm pump piston, gov mod and omfg does it smoke, if i punch the thottle it fills the street with smoke, wen i cum on boost around (40psi atm) i believe the pump is chucking in more fuel than the centrifugal pump can suck into the pump Reservoir. so wen i cum off the gas it stalls, and wen im on the gas its slowing me down.

has anyone cum across this before? does anyone run an electric fuel pump to prevent this, TDIs do dont they
Title: aaz under fueling, has anyone heard of this?
Post by: the caveman on April 09, 2008, 04:09:04 pm
TDI's don't have an extra pump. PD's have a mechanical pump on the head  to the feed the line and some may have a lift pump in the tank. Maybe your fuel demand is so high you are emptying the line and filter so that when it's time to get back on the throttle there's no fuel left. I have a similar problem with older GM 6.2 and 6.9's running on VO. If i don't put in an extra lift pump they will run fine until i lift off and then when i get back
on the pedal it'll stall.
Title: aaz under fueling, has anyone heard of this?
Post by: oldskool rich on April 09, 2008, 04:27:07 pm
safe, ill get me a pump tomoz

im drag racing the old caddy at the wkend so i want as much power as possible dont wana stall b4 i reach the end :roll:
Title: Re: aaz under fueling, has anyone heard of this?
Post by: jtanguay on April 09, 2008, 04:55:38 pm
Quote from: "oldskool rich"
wen i cum on boost around (40psi atm) i believe the pump is chucking in more fuel than the centrifugal pump can suck into the pump Reservoir.


i think you have a good theory right there...  if i were you i would get a gauge put on the out port of the pump.  would be interesting to know what psi levels when the pump is screaming  :twisted:
Title: Re: aaz under fueling, has anyone heard of this?
Post by: oldskool rich on April 09, 2008, 05:58:28 pm
Quote from: "jtanguay"
Quote from: "oldskool rich"
wen i cum on boost around (40psi atm) i believe the pump is chucking in more fuel than the centrifugal pump can suck into the pump Reservoir.


i think you have a good theory right there...  if i were you i would get a gauge put on the out port of the pump.  would be interesting to know what psi levels when the pump is screaming  :twisted:


where cud i get a gauge to measure that?

the AFN pump that i took my pump piston & head off produced 22,306psi according to bosch :shock:
Title: aaz under fueling, has anyone heard of this?
Post by: bert on April 10, 2008, 12:18:45 am
try a low pressure facet feed pump,cheap on ebay,will help feed that hungry pump  :wink:  whwrw you taking it the weekend bert? or shall i look for smoke signals  8)
Bert
Title: aaz under fueling, has anyone heard of this?
Post by: oldskool rich on April 11, 2008, 07:46:53 am
OMFG ive just used a pump off a polo carb and it works amazingly well, no stalling or annoying flat spots, very smooth. i was very suprised it worked, deep down inside i never thort for one second it wud.

i love it wen a plan comes togeather 8)

this weekend ill be at santa pod (spring fest)

my truck is running better than ever before, im confident it shud eat sum vr6 hopfully :twisted:

every time i drive it it puts a little smile on my face, you know the kind that you cant get rid of. and wen i get out my hands are all shaky and sweaty :oops:  is it wrong to feel this way about a car?