Author Topic: How do I determine what length accelerator pump shaft to use ?  (Read 4033 times)

Offline 73 Z28

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Was rebuilding a q-jet following recipe #3 over the weekend and while going through my spare parts, I got the accel pump mixed in with some spares. Of course, after looking at the accel pumps, I discovered that there were about 3 different lengths. The carb casting number is 17057204. Of the pump lengths that I measured, one was 2.392" one was 2.537" and the third was 2.756" Can you tell me which one is the correct length to use for this carb ?

Thanks in advance
 ???

Offline Cliff Ruggles

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Re: How do I determine what length accelerator pump shaft to use ?
« Reply #1 on: June 02, 2009, 04:18:10 AM »
If you are "rebuilding" the carburetor, you "kit" should have included the late style pump with a dark blue ethanol compatable seal/garter spring.  There is no reason to install a used pump, they wear out inside the plunger end, and the plastic gets hard and brittle with age.

The springs on the pump and under the pump should also be replaced, if you want/expect it to delivery fuel like it's supposed to?

We sell complete HP pump assemblies with upgraded springs/retainer for $12.

There are at least 30 different pump lengths for the various models, and the spring retainer location varies as does the rate of the delivery spring/delay spring that was used.

We see lots of incorrect pumps supplied with currently available "kits", if you are lucky enough to even get a pump at all, and none of those kits will contain new springs, or a new plastic secondary cam/spring, high flow Viton needle/seat assembly, etc, etc, etc.

Bottom line, if you want your carburetor to perform like it's supposed to, by ethanol compatable parts, and replace the items mentioned above.  Do not use anything rubber inside your carburetor, it will not last very long in contact with modern fuel blends.

If it sounds like we are trying to sell parts, you are correct.  Among our goals here are to make sure that you have a positive experience with your Quadrajet carburetor.   When correctly rebuild and calibrated, it will outrun anything else out there, on the street or at the track, and get a LOT better fuel economy along the way.  At least 80 percent of the calls and emails we get to the shop start like this, "I just rebuilt my carburetor and it ran OK for a few days, then....."  My first question is "where did you get the parts".  Then we go into a lengthy discussion about how currently available kits do NOT contain ethanol compatable parts, enough parts, or even the right parts for a successful rebuild........Cliff