My car just started having bad hesitation, a rough idle and the oil pressure jumping around when idleing. The car will run great when it is cold and I first start it but about 2 minutes after driving it just runs like sh*t. I have new plugs, o2 sensors, opti, cap & rotor, ICM, coil and IAC. I think it is the fuel pump or the regulator. I do not know where I can get my fuel pressure tested and think its worthless to buy a $40 tester for one use. Any suggestions would be greatly appreciated. Also, what would be a good fuel pump to get since I don't have much money? How hard is it to instal and inline? What PSI pump would I need o run a stock LT1? Is a stock pump easier to install? I'll probably remove thepump from the top of the tank w?o dropping it.

 

Sounds like a closed loop problem if it runs fine when cold. That would rule out fuel problems.

 

Go ahead and buy the fuel pressure tester believe me you will use it more than once. I have a black bag that I keep all my diagnostic equipment in Scanner, multimeter, noid light, fuel pressure guage and it comes in handy trust me.
I cut a hole to get to my fuel pump from the top and its been a good idea for me I have had to get to it several times and with the hole its easy.
Install will be the same whether you go stock or an upgraded pump so I personally would spend the few extra dollars and buy a good aftermarket pump.
It does sound like a closed loop problem and if you can get ahold of a scanner you should be able to pinpoint the problem, they are kinda pricey but they come in very handy when working on these cars.

 

would have to agree with Loadre - fuel problems don't typically surface only when in closed loop mode. Before you throw a bunch of money at it, invest some into a cable from Andrew Mattei (www.akmcables.com) and scan the car first. If you aren't sure after that, post the scan results up here so we can see it and maybe we can give you some places to start looking.

 

get this cable and find some good software, trust me this will become your best friend in time...

 

when you say runs like $#@! do you mean runs bad or maybe cuts off sometimes? When my fuel pump went bad my car would crank when cold and then cut off after a few mins. It did the same thing when the Ignition control module went bad. Just some ideas from my experience. By the way, buy a fuel pressure tester or go to a shop like Meineke or something. They will usually test your car's pressure for you for cheap, just tell them you are thinking about getting them to change the pump when you get a few $$ saved up, even if you end up doing it yourself. I bought a pressure tester after I replaced my pump just to see how the pressure changed from bad 18-24 psi to new pump 42-44 psi at idle. Read the directions to it carefully also. I can use it now to rule out any problems that may come up down the road. Worth the $37. The fuel pump I installed was the Walbro 255 liters per hour unit in the tank. I got it from Summit for $129 and installed it myself. If I remember correctly, the Fuel pressure regulator troubleshooting check is to turn the key on without cranking, pressurize the system, and then remove the vacuum line and check for fuel in the vacuum line or port on the regulator. This is where it would also be nice to have a fuel pressure tester guage. Hope this helps rule out something. Listen to the other posts and check their advice too.

 

What exactly do you all mean by "closed loop". I am not too familiar with electrical. can someone please explain to me how this works. I am going to buy a pressure tester today and find a scanner. I have a 93, so I need a different type than most of you are using. Where did you all buy your scanners at? My local parts store wants $190 for a stock pump! I need a used one or an aftermarket on if that is the problem.

 

You need a Racetronix pump is what you need. The basic kit is around $150 I think and then the series-II plug and play is just north of $200.

 

Whats good about the racetronix FP? I do have a little hesitation when I first start the car, but the longer I drive the worse it gets. It won't take off (just boggs and sounds like a V-TWIN, than slowly moves), and at idel the car jumps around. Every few seconds the car will lunge foward a little and shake around. If I put it in nuetral the engine stumbles but the car stays still.

 

dont go out and buy a fuel pump just to find out later its not that.... get a fuel pressure test done and know for sure