bluedodge3500

Installed vulcan kit,stock lp on frame fuel pressure gauge with isolator and Genos fuel pressure hose,turn the key on goes to 15 psi,start the truck goes to 14 psi,driving around town 35mph plus 14 psi wot 11 psi,heres the problem if i drive 25 mph or less gauge goes fron 14 psi down to 11 psi and back up to 14 psi,when you stop at a light it goes down to 8 psi,when you take off it goes to 14 psi checked for leaks and bleed isolator,still problem any ideas what it could be

P.J

You say "new" fuel pump. Do you mean, the pump is new or this is a "new" question?

I wouldn't trust it if it is a new pump. Other than the drop at stop lights your numbers are identical to what mine where with my old Carter pump and the Vulcan kit.

bluedodge3500

search the fourm for this question but could not find the problem I am talking about and yes it is the carter pump

P.J

So, the pump is new?

Any chance you're getting a voltage drop to the pump at those times?

bluedodge3500

tonite after work I am going to see if it is a voltage,I might change the pump also I have a spare

bluedodge3500

well checked voltage it was good I replaced pump this morning the pressure is up at idle it is 17 psi with a stock LP driving around town it is 15 psi wot it is 13 psi drove it about an hour gauge didnt drop will run some more tonite and give up date later

P.J

Sounds like you've got a winner!

More and more I keep hearing of pressures over 15 with stock pumps. My old pump was 15-15.5 idle, couldn't drag it below 12 in any situation. My new one is more like 12-12.5 idle and 9 WOT.

bamadzl

After installing gauges my fuel pressure was exactly as you described. It continued to worsen until I finally replaced the carter with a Holley Blue.

Brad

bluedodge3500

Well hope this was it, it takes me about an hour to get home tonite I will find out by the time I get home let you all know in the morning

bluedodge3500

well driving the truck around last night and today no problems dont get why fuel pressure would drop when you stop the truck then go up when you give it throttle I am guess the fuel injection pump was helping it get moving again well another problem fixed