I am trying to get a 1990 mazda b2600i running but it won't start. it's getting spark and air ,but no gas, i replaced the fuel pump and fuel filter, and fuel rail but still won't start. i replaced the fuel pump after i couldn't get gas through the fuel regulator, now it's getting gas through the regulator but won't start. it will start when i spray starter fluid through the air intake, but dies after seconds.before i replaced the fuel pump it would start if i bypassed the fuel regulator,but it was getting to much gas. can someone help me please?

That sounds like either a fuel issue; too rich, or an air leak in the manifold.
If it were an ignition issue, it woukd cut out, not run rough.

Faulty fuel pump or fuel pump relay. Locate the fuel pump relay. Remove it. And turn the key on again. Check if fuse is holding.

clean out charcoal box filter and try to blow line out from charcoal box to fuel tank with low air pressure from a air compressor

Try changing the fuel filter.

Have a fuel pressure test done on the fuel manifold to check for pump, filter and fuel regulator problems. Run fault codes to check for evap canister solenoid problems

An engine needs three things to function correctly: (1) the right amount of fuel; (2) the right amount of air; and (3) an appropriate spark. I would also add a fourth point for a gasoline engine: appropriate compression in the engine. A worn-out engine won't perform well, even if items 1-3 look good.

Poor fuel flow is one possible cause of poor performance. A clogged fuel filter is only one possible cause of that. You might have a weak fuel pump, although with the electric fuel pump on this car, that would either have the car running or not running at all, not running poorly. You might very well have a clogged fuel injector--gas is getting there, but an inappropriate amount is getting sprayed into the combustion chambers. You might also have a clogged fuel intake screen inside the gas tank--the fuel pump might not be able to **** up enough fuel.

Air is another possibility. Check your air filter. Is it clean? A clogged air filter will cause incomplete combustion when you step on the gas because not enough air is getting in to create a proper air/fuel mixture. A simple test for this is to try running the car--VERY BRIEFLY--without the air filter. Does it run better? You should not run your car without an air filter for any longer than diagnostic reasons--sucking dust and dirt into your engine is a fast way to ruin it--but it's an easy and essentially free test you can perform. Or you can just replace the air filter if the one you pull out looks nasty.

A final consideration is spark. If you have a weak spark, you won't get as strong an explosion in your cylinders, yielding less power and stumbling. Or, if the spark comes at the wrong time, you'll have the same problem. You can check for a strong spark by taking a spark plug--an old one, a new one, one that doesn't even match your car, and using it to test the spark coming off each of your spark plug wires. Attach the plug to a wire you disconnect, ground the tip of the wire against exposed metal on your engine, and look for a nice healthy blue-white spark. If you see a yellow or orange spark, that's not so good. That could indicate a weak ignition coil--or also old spark plug wires that are leaking voltage. Spark plug wires should probably be changed every 5-6 years; they're not a lifetime part of your car.

A final consideration I didn't list previously is that you may have a bad O2 or other sensor that measures and adjusts the air / fuel mixture. A bad sensor will force your car's computer to operate on a default profile designed to let you limp home. However, it won't perform particularly well.

Good luck; I hope this gets you pointed in the right direction.

Are the plugs wet with fuel?
Check for spark. No spark? it may be the ignition module.

Plugs dry and spark present? No fuel?Spray a little starting fluid and see if it will run on that.
Then check pump fuses and for fuel pump noise.

Have your engine scoped out by a reputable service shop. Was it running better before you replaced those items? Have you done a tune up lately? Did you buy bad gas? Are your fuel injectors clean? Is the fuel pump going out on you? Are your spark plugs and spark plug wires good? Are their any sensors that may need replacing? I have a 1990 Honda Accord and the car just wants to keep taking my money. It needs too much love to keep any more.
Terry

try rockauto.com

Well lxmccarthy, since you put a new fuel pump in, check a hose after the pump and see if any gas is being delivered. You can also try some starting fluid in the carb to get something going. There probably is just some air in the fuel line.