Fuel pressure dropping
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From: Chicago IL/ Lake Geneva WI
Fuel pressure dropping I have an interesting combo to say the least. I have a 99 LS1 swapped in to a 99 V6 body. My fuel system is comprised of using the V6's body length lines, the V8 bucket, Walbro 255lph pump, and a C5 filter/regulator combo at the rail to utilize the V6 return setup. While having the car tuned, we noticed that it was going very lean on spray. 15.0 AFR, but still good plugs. Fuel pressure gauge shows over 60psi at idle, and around 30-35 at WOT. What am I doing wrong here. Replaced the V6 fuel filter last night and picked up some added flow, but not much. Also picked up some flow removing the C5 filter/regulator at the rail, but not enough to overcome the lean issue.
Did you clean the tank and/or the bucket and do you have a prefilter before the pump? It is very possible there is a restriction in the form of dirt that is inhibiting the FP from keeping the necessary pressure under WOT. Also, make sure your return is working properly and in a spot that isn't blowing the fuel right back in the path of the pickup.
Thread Starter
10 Second Club
iTrader: (12)
Joined: May 2004
Posts: 930
Likes: 0
From: Chicago IL/ Lake Geneva WI
Did you clean the tank and/or the bucket and do you have a prefilter before the pump? It is very possible there is a restriction in the form of dirt that is inhibiting the FP from keeping the necessary pressure under WOT. Also, make sure your return is working properly and in a spot that isn't blowing the fuel right back in the path of the pickup.
Your configuration makes no sense...
Are you saying you have a filter in the factory location & a Vette filter in the front.
I'll assume you removed the v8 intank regulator... if so how did you run it without the vette filter then? Pressure would have been sky high then.
If you have a vette filter, you need no other filters.
2 filters will hurt your flow sinificantly.
If you have over 550rwhp, your pump is too small.
Are you saying you have a filter in the factory location & a Vette filter in the front.
I'll assume you removed the v8 intank regulator... if so how did you run it without the vette filter then? Pressure would have been sky high then.
If you have a vette filter, you need no other filters.
2 filters will hurt your flow sinificantly.
If you have over 550rwhp, your pump is too small.
When we put the bucket and pump into the V6 tank(I think it was the V6 tank, he might of swapped over the whole v8 tank), it had no vetter filter(regulator) and had super high FP. So as a temp fix, he put the vette filter(at this point it was being double filtered) just so that it would regulate the FP as for some reason the stock one wasn't...
