camaro0605

iTrader: (4)

I swapped an ls1 into my 91 camaro and put the ls1 plastic tank in. I oriinally put a pump that came with the tank in there and i was getting 20 lbs pressure and then it would immedietly drop to 0. I was worried it might have had something to do with the cup/hoses/regulaters so i bought a new unit off of ebay. Sure enough when i took the old one out the small tube that fills the cub was broke and i think that was my issue.

Now after i got everything back together with the pump i got off ebay i'm only getting 40 lbs of pressure at the fuel rail. The pressure is holding this time. But the car will not start. When i start it it fires real fast and then dies within a second. Do these cars need more than 40 lbs just to start?? I figured it would start but then maybe starve itself of fuel when the rpms go up.

I was thinking now that I changed the sending unit i could upgrade to a better in tank pump. But i'm worried that it might be the regulator and changing the pump would have no affect.

Any suggestions and help is apreciated.

Lonnies Performance

iTrader: (16)

There could be a few issues....

First, you often get what you pay for with generic pumps.

Second, your pump install may be causing a fuel delivery problem.

Did you try jumpering your pump so it runs continuously & see what the pressure is & if the car runs then?

What regulator did you use & how is it hooked up?

camaro0605

iTrader: (4)

I know i took a chance with this pump, but i knew i needed the whole assembly and not just the pump.

I did not try jumping the pump. I'll have to do that. Problem is though the car is 2 hours away and i probably won't be working on it for a few weeks again.

I'm using the regulator that came with the assembly that i bought off of ebay. My fuel system is set up like an 99-02 camaro with the regulator at the tank.

Lonnies Performance

iTrader: (16)

Since you bought a pump/regulator combo, it is hard to determine which is the cause.

After jumpering the pump to see if it makes pressure, you can try crimping off the return line to see if the pressure jumps up.

camaro0605

iTrader: (4)

Can anyone recommend a good replacement sending unit. As much as i'd like to upgrade the pump i need to have a complete working sending unit first. I'm trying not to spend $600+ on the oem one.

Lonnies Performance

iTrader: (16)

An OEM is typically under $400, but the recent GM replacments are junk & appear to be the same stuff that local autoparts stores now sell.

If you do the tests that I recommended a few days ago, you may be able to diagnose the problem without wasting more money.