Dellorto Experts - Check me out Options

[bandjoey]

Car has a 1.8 that was rebuilt before I bought the car. The PO doesn't know what was done or size of the rebuild...he just paid the bill to make it run.

It has DRLA carbs. It came with a Tomlinson Tech book, and in the back of the book is written:
140 Main
9164 2
60 Idle
34Mm Main Venturi

I bought a Pierburg rotary fuel pump from a local shop and was told it didn't need a pressure regulator at the time - it had an internal regulator that put out 3.5lbs. Can anyone confirm this or do I need to get a fuel pressure gauge to test the pressure? If I need a regulator, what's the right one to get.

The motor runs strong and pulls with torque from 3000 up to 5000. Occasionally, I'll hear a small single pop from the carb when I step on the pedal, but it's not often.

However, my gas mileage stinks, and when I start the car after it's been sitting for a few days, there's the distinctive smell of the old lawnmower starting up - that pukey gas smell out the exhaust. Within a couple of minutes, the smell is gone.

I'm going to go through the entire trouble shooting process this weekend from the book. Valves, timing, sync the carbs, and adjust the mixture etc.

??? Exactly what do the numbers above mean and mean to me? Are these carbs a good size for a 1.8ish motor? Suggestions of what to look for with bad gas mileage? Any DFW Dellorto experts that want to supervise? Thanks All.

(yeah Clay, I'm going to work on the FI back on this winter (IMG:style_emoticons/default/smash.gif) )

[nathansnathan]

I bought a carter rotory pump that claimed to put out 3.5 psi, but my gauge puts it at over 5psi. Yours is probably about the same. I got a holley regulator, and put it to 3.25psi.

Those numbers are your main gas jet, emulsion tubes, idle gas jet, and main air venturi sizes, which sound about right for a 1.8.

The pop to me sounds like a problem with one of your accellerator pump diaphrams. You can check that by taking off the air filters, and pumping the llinkage while looking down the carb throats, the car turned off. You should see a squirtgun like stream down each barrel, a shot past the butterfly valves. Probably 1 or so is not firing on account of a dry/ brittle/ cracked diaphragm, and that makes it lean then, thus the pop.