sammyb

I went out to do a story comparing the new Passport G-Timer to G-Tech, so I hooked the G-tech up to my C5, and it told me I had 304RWHP (which seems right when tested only in 1st gear.)

Then I hooked it up to my '69 and could only muster 220hp!!! I started thinking that, yeah, the car surges and then falls off around 3000 RPMs (when it should be picking up.)

Took the car to my mechanic buddy, and he drove it and said: "yeah, the engine is falling on its face. Your fuel pump is probably going out. That's probably why the automatic wants to shift from 1st to 3rd under WOT."

The car also is idling crappy, but I think it's more that the carb needs to be rebuilt.

Any ideas?

I guess the good news is that I ran a 13.8 1/4 in it with something really wrong...it should be more like 450hp!

gkull

Do you have modern electronic ignition?

You would be suprized how far a car can go with just the fuel in the carb bowls. I had an electric pump and every once in awhile I would forget to turn it on. I could drive 1/4 - 1/2 miles before the motor would die. It wasn't RPM limited either.

It's easy to test a fuel pump. Just pull your coil wire so the motor doesn't start. but have the motor up to temp. Pull your fuel line hose off and attach a longer rubber fuel line and aim it into a container. Then have your buddy turn the motor over with the key. If it's putting out good hard pulses of gas. Look at float levels and ignition problems.


[Modified by gkull, 1:51 PM 9/4/2003]

dogboy

I was having a similar problem for awhile. I wasn't able to rev past 4500 rpm's. The car was okay up until that range than would sputter and fall flat. I changed out the old fuel pump but still had the problem. This plagued me for about 3 months until it just stopped running in traffic one day. To make it short a coil pickup wire in the HEI distributor had cracked off from age & heat. It was probably just hanging on by a thread enough to power the car. I changed it out for a total of $16.00 and it revs well into the 5 g's again. big difference now.

sammyb

It has a modern electronic ignition system...I'll check the wires first, since it's a lot easier than swapping the fuel pump (getting to those bolts on the big block is hard as hell!)

sammyb

Wires on the electronic ignition (MSD dual spark) are fine.

Maybe the fuel pump next.

Smokehouse69

Sammy, remove the right front wheel and you should be able to get to the fuel pump bolts fairly easily. I spent 30 minutes one day working on one bolt, then I noticed that the path to the bolts was wide open over the top of the A-arm.

Also check your fuel filter! I don't know what type of carb you have, but Q-jets have a small filter right where the fuel line enters the carb. This filter plugs very easily.
Good Luck!


[Modified by Smokehouse69, 9:45 PM 9/4/2003]

sammyb

Ahh...good idea on the wheel removal Smokehouse69!

I actually have two filters...the yahoo last owner put one directly under the gas tank (which I just replaced) and I put one right before the carb about 6 months ago (clear, so I can see if anything gets by the first filter.)

My carb is a Holley 780 double-pumper, so no little filter like stock.