fuel pressure question

[SPS]

I just installed a walbro 340 pump and hot wire kit today. Every thing went fine and started up fine. The reason I changed was because I only had 28lbs of fuel pressure with the hose on and about 30 with it off. Now after changing the pump I have 32lbs with hose on and 38 with it off. Is this normal pressure or is it too low? I thought it was supposed to be around 40-45 lbs. I tried a search but didnt come up with an answer. What else should i check? It also pops out of the throttle body when reving the engine, which I thought was due to low fule pressure???

 

[BoostKillsStres]

do u have an adj regulator? stk regs supply about what your seeing.

 

[SPS]

fuel

no its stock. this is the first mod i have done per everyones suggestion on the board. Its a 85 wh1 t-type w/ 70k miles. I really thought it should have been higher even stock but maybe not. I need to start checking sensors I guess. The way it pops it sounded like fuel pressure. thanks for the help

 

[2QUIK6]

Re: fuel

Originally posted by SPS
The way it pops it sounded like fuel pressure. thanks for the help

Is that a pop under boost or a pop as in knock while under boost?
A pop like a backfire thru the intake can be a bad coil/ignition module. A pop like knock/preignition detonation is not enough fuel, too much timing, or too much boost are most likely causes.

 

[SPS]

POP

ITS A POP BACK THRU THE INTAKE. I NOTICED TODAY THAT ONCE IT WARMS UP IT DOESNT DO IT AS BAD. WHEN YOU FIRST STAR T IT COLD THE ENGINE SURGES UP AND DOWN FOR ABOUT 5-10 MINUTES, THEN SETTLES DOWN TO A DECENT IDLE-IS THIS NORMAL? LAST WEEK I REPLACED ALL THE VACUMN LINES. BEFORE THE CAR WAS KINDA SLUGISH WHEN YOU FLOORED IT, THEN ABOUT 30-40 FEET OUT THE TURBO SPOOLED UP AND BROKE THE TIRES LOOSE AND FELT LIKE YOU BEEN HIT IN THE ASS. NOW AFTER REPLACING LINES AND FUEL PUMP THE POWER FEELS MUCH MORE LINEAR BUT NO WHERE NEAR AS STRONG. THIS IS MY FIRST TR AND THE ONLY ONE I HAVE EVER RIDDEN IN SO I DONT KNOW IF ITS NORMAL NOW OF IF I AM DOWN ON POWER. I DID NOTICE SOME CRACKS IN THE MANIFOLDS SO I GUESS THOSE NEED TO COME OFF TO GET WELDED. ANY MORE IDEAS?

 

[SPS]

anybody???

 

[87gninpa]

definately get the manifolds welded, particularly the driver side. thats whats leaning out your fuel mixture. also, 38psi line off is about right for a stock regulator, so if youd like to raise it, get an adjustable regulator. like 2quick6 said, if your'e popping is through the intake, id check your coil and module as these tend to go bad over time. also check your wires and plugs for correct gapping. first thing id do is get those manifolds welded up by a good shop so you only have to do it once, then go from there.

 

[SPS]

ok thanks- looks like i need to start checking ignition. next project is to pull the manifolds off. thanks again for the info

 

[87gninpa]

no problem, anything else, post another message.....a lot of people overlook the header cracks, i know i did and getting it fixed solved a few problems i was having