After taking my car to the track i have noticed that it is not running correctly on the top end. This problem also occurs when i am finishing a burnout (pulling forward) and the RPMs are being held at a high level (4500+ or so). In the top of first gear the engine runs fine, in the top of second right before the shift it starts to sound like it is missing out and losing some power, the, in most of third gear this happens. It is kinda hard to describe but it sounds like the engine is not running smooth at all (feels like it too).
So here is my guess:
My stock fuel pump in the tank failed and i needed the vehicle repaired very quickly so i took it in to a shop. They installed some generic cheap electric fuel pump on the front inner fender and they have it sucking through to stock pump. Could it be that this cheap POS fuel pump mounted on the fender well (when it should be very close to the tank) is not feeding the carb enough fuel?

ps: this problem seems worse with the amount of load and/or throttle you are giving the car

thanks
brady

 

Check timing

 

what kind of car/engine/trans combo do you have? a little more info would go a long ways

 

Well, if it's a carbed car... I'd say the fuel pump isn't up to the task. I thought electric fuel pumps push the fuel better than sucking it a long distance like that?

 

i agree with evil eletric pumps should be mounted as close to the tank as you can get them. you may be running out of fuel, you may have reached the physical limits of your engine.

 

It's not the timing.

It's fuel starvation. I agree, you should be looking real hard at the fuel system. It's likely to be an accumulation of crusties all built up inside the pickup tube in the gas tank, part of the gauge sending unit actually.

Do what ede suggested, if you have an electric pump, try mounting it as close to the tank as possible, they are very poor at sucking fuel, but push it much better.

If you have a stock type mechanical pump, try a lightweight fuel pump drive rod from Moroso or whoever.

 

im confused.. so its a carbed car with a burnt out electric pump in the tank still.. and someone put another electric pump up front for a quick fix? why not just put a mech pump on the block and use the burnt up pump as a pickup until you have time to replace the burnt pump with the correct pickup for a carbed car? so much ******* engineering goin on to 3rd gens these days.. i just got done reading the thread about the guy who actually tried cutting out his y-pipe instead of unbolting it just to replace a starter and cut through his oil pan as well

 

So what did you run?

 

The car is carbed, 700R4 tranny with a stock torque converter, 3.73 gears and the SLP take-off posi, 295/50/16 tires, suspension is all stock minus some poly bushings here and there and the drag shocks in the back (50/50) and air bags in the back (5 psi drivers bag, 12.5 psi passengers bag).

The carb is a Edelbrock 750 CFM electric choke. The fuel pump is a no-name brand, and is mounted on the front fenderwell in the engine compartment.

Here is another bit of information that might contribute to the answer: We made some adjustments on the air/fuel screws on the front of the carb. What i did was richen up the motor basically. After this change the problem got worse.

Could it be that i took an already fuel starved car and just made it worse?

I think its the fuel pump, and if it is i am just going to buy a really good mechanical one and use my mallory 3way regulator to tune the pressure to the carb.


2.27 60' time
9.05 @ 81.14 1/8 mile et and mph
13.88 @ 99.91 1/4 mile et and mph


That was my best run although i had my worst 60' and the missing out was bad! ( i let off the gas not knowing if i had crossed the finish line or not)

thanks
brady

 

He had a TBI car that was converted to carb.

Its fuel starvation, definatly. At high RPM's, the carb's fuel bowls are running out.

Do you have a fuel filter? Change it, it might be clogged.

If not, check the lines, see if they have anything blocking them.

All else fails, change the fuel pump.

 

LOL

(I'd make a suggestion, but everything seems to be covered pretty well already)

 

By richening the carb, what you did, was to enable the engine to drain the fuel bowls faster. That's why it made it worse.

Like I said, a textbook case of fuel starvation.

 

Yes sir......
That's what I thought. A 110 GPH mechanical fuel pump will be on its way soon. Does anybody have anything to say about this fuel pump?

http://store.summitracing.com/partdetail.asp?part=7627


Thanks,
Brady