Noob question

Everybody says they get 20+ mpg with their trucks even with weber and pacesetter mod. My 86 b2000 has the weber and pacesetter and gets low teens (10-12) city all the time. I replaced air filter (with taller version) and used gumout to flush fuel system and got 20 but I drove all highway on that tank. The previous owner did a miata trans swap. Any ideas for fixing crappy mpg? Fuel filter im doing next but will tire pressure affect this much? The recommended tire pressure is 26psi front and 34 rear. I have 35 in both because 26 seems low... what pressure is everyone who gets 20+mpg running?

Tire pressure will affect mileage. Who recommended 26 lbs in the front? That's crazy, unless the tires themselves require it. If that's the case I'd change the tires. I use 32#s in all tires.

Make sure your timing is set correctly, you are measuring the mileage correctly and consistently. Incorrect calcs can be misconstrued as bad mileage.

Do you have a tach? If so, what is your RPM's at 60MPH? I have an RX-7 trans, and I am at 2100RPM at 60MPH, and it may be lugging the motor too much, consuming more fuel if yours is simmilar.

But, I would also check timing, do a full tune up, new plugs, wires, distributor cap & rotor. How are you driving city? If you are trying to keep up with traffic like I had to when I had the stock motor in my truck, I was practically drag racing all the time lol, which used lots of fuel.

Another obvious thing to check is that your choke is disengaging fully.

The 26 comes from the owners manual and sticker in the door jam. And its around 3000 rpm in 5th gear doing 65ish onhighway. How do I check ttiming? Just changed plugs because previous owner had premium plugs in it. If I do tune up what's recommended? Kit from rock auto or anything specific like not premium or a certain brand?

That recomenation is from a era gone by, increase your pressures to 32 on all four corners.



No, no premium parts are needed. Just buy OEM spec plugs wires etc...

Here is a timing tech article.

And more on the B2000....

+1 on the full toonup (yes I know it's Tune-up).

Okay thank you. Much appreciated.

Another question.. The two lower flaps on weber in carb barrel... should both open when throttle is pressed? on mine only left opens. I think the right one might only open during wide open throttle but may be wrong. Any advice?

Your mechanical advance in the distributor may be stuck. Connect a timing light on it, paint (white) the crankshaft pulley timing mark. Disconnect the vacuum advance from the distributor and plug the line, start it. If it will not idle, adjust the idle until it does, remembering how many times the idle screw was turned in to accomplish this, write it down. Now with the timing light on the timing mark raise the r.p.m. a thousand, any change in timing position? Raise the r.p.m. another thousand, any change in timing position? If not, the mechanical advance is gummed up and stuck probably, best case.
Remove distributor, disassemble, check condition of advance bearing, clean, lubricate or replace as necessary. Reassemble, reinstall, put vacuum line on, return the idle adjustment screw to the original position, start it, good luck.
Not sure on carb, probably is full throttle opened, my dualjet (half a Quadrajet) on my B2600 is.

The weber is a progressive carb so the secondary won't open until you get rolling and give it more fuel...

Dan

Thanks Dan I thought that might be the case. I gave my truck a tune up and tuned the carb and the gas mileage is legitimately better. Averaging 17-18 mostly city with a massive exhaust leak at header/midpipe flange. Should break 20 when I fix that.. I have one question again.. has anyone done anything that improved the ride on the truck? I know it's a truck and won't ride amazing but im looking to make it ride smoother. Stock shocks up front and air shocks in back. Maybe new shocks? Or bags? Any advice appreciated.