Leave it unconnected. While operating, it will behave just as the other carbs, when parked it will be closed, and help control evaporation.
Thanks for the input, I was waiting to hear from you as well.RWG75 said:The solenoid on the throttle is part of an emissions package your truck never had. Probably lean burn only but the idea was to energize the solenoid and hold the throttle slightly open. The objective was to avoid dumping a load of unburned fuel in to the cat when hitting the off ramp.
I assume every TQ to be not only rebuilt, but rebuilt with mismatched parts and therefor the 9xxx number on the throttle plate is mostly irrelevant. Take for instance the first one ya posted here - absolutely not a 70s 400 truck carb. Biggest give away is no port for dist vac adv, other tell tale sign is 80s style fuel inlet. BTW, adding the dist port is pretty easy - stare, compare, drill.
Tear down, clean up, correct parts selection, assembly is the easy part. These things are insanely sensitive to control rod adjustments and that's where having a few running examples really comes in handy. The bonus fun is that a couple functions depend on multiple linkages and some are connected in ways you don't expect.
That's on the lean side at idle and part throttle and this is where is basic spreadsheet skills come in handy as it helps when comparing jet / rod combos. Last two digits of the jet number are it's diameter. The effective jet size is the rod diameter subtracted from the jet diameter. 4098 / 1998 results in .028 - .036 - .058.W200'78 said:This carb came with 4098 primaries, 5143 secondaries and 2159 rods.
The carb on my truck when I bought it had 4098 primaries, 5125 secondaries and 1998 rods.
So I have a set of larger secondaries now. The 2159 rods are a little leaner in the mid range than the 1998 rods. .070-.062-.040 vs .070-.057-.040.
You mean rich in the secondaries? Or do I need a metering rod with a larger small diameter on the primary side?RWG75 said:random WOT burst are therapeutic, rewarding and great for cleaning plugs.
jet / rod size looks a bit rich on the top step.
Im still messing around with the edelbrock right now. Havnt swapped back to the TQ. I found a few things I did wrong on the initial install a while back, the biggest being that I didnt properly adjust the throttle cable and was only getting about 80% throttle with the pedal to the floor.dodge82273 said:how does it run ?