Just picked up a 1994 b3000 v6, automatic transmission, 2wd. 260000 on the odometor, supposedly the engine was just rebuilt a hundred miles ago. But When i got the truck 2 days ago it ran fine, had a valve tap up top but thats not the problem. Ill be driving down the road going about 35 then the car will just be unresponsive, i can tap the gas pedal or even pin it and it will do nothing then after about 30 secs the car will start to rev up just fine then drive just fine. But when it starts to stall it will also have a small knock in the lower part of the engine on the passenger side, i believe its a back fire. But all the sensors are new, he said he had the computer checked and it was fine. Said the timing was off because when they redid it they just set the distributor in and rotated it until it was sound. But after driving home from work it only cut out once and knocked about 10 times. So it only happens sometimes. Im at a complete loss for what it could be. The cap is new, wires are new, said the plugs are new he just didnt gap them. The car just kinda back fires if in park and revved up but will never stall. Sometimes sitting at a light it will start to bog down and periodically it will stall out. the truck is straight piped. Thanks a ton for the help.

 

After major surgery small things can happen. Let's hope it is a small thing.
check all electrical connections and all ground connections. Have the battery and the alternator tested. Pull the plugs and set the gap correctly. Make sure they used the correct plugs. Disconnect and reconnect all wire harnesses.
check for vacuum leaks.
Read the codes. It might help narrowing down the problem.

 

Well today the car died at the top of a hill, so i coasted down and made it to the bottom and on the shoulder. The entire time of driving the car wouldnt go about probably 45, it shifted very late and the only way to give it any gas at all was to pin the pedal to the floor. After checking for spark with a screw driver, (thats all i had) I found from the coil pack i wouldnt get a orange spark. But when removing the boot from the spark plugs and using a screw driver i got nothing. The car tries to start but kinda sputters and just wont start. Bought a new battery because the old one died and couldnt be jump started. Sorry i dont know the name of this part, but where air is sucked into the engine the black plastic piece, normally would have an air filter attached was flooded with what looked like gas. I tipped it upside down and gas just poured out of it. enough to cover the bottom of a cup. The rotor and distributor cap are new apparently. Iac, And tps are new. What else could it be? And how do i check for codes? I've never had to read codes on a Mazda so i dont know. Pllus i believe the check engine light bulb may of been removed because i unplugged some of the sensors when the car was running and it never came on. Could this be a bad ECM? Thanks again in advanced for responding

 

You may have several issues. With that many miles on it I would start with a compression test. If that is horrible than you look for a replacement engine rather than fixing things around this one. If it turns out acceptable then we look firther.
I would start with a fresh coilpack, wires and plugs. Buy nothing fancy, stay close to original equipment.
There should be no fuel in the air air intake hose. I can think of two ways that fuel managed to get there: 1. The fuel pressure regulator may have a broken membrane and lets fuel into the intake manifold by way of a vacuum hose.
2. If the piston rings are worn or stuck unburned fuel gets into the crank case and from there into the PCV and from there into the air intake hose. this second scenario is more likely than the 1st. It is one more reason to start with a compression test.

It would be advisable to put in a new bulb for the CEL indicator. The ECM can go bad but that is not very common.
You may go to a parts store and borrow a OBDII scanner. It plugs in a port that sits near the steering column. If you manage to get the vehicle tot he store they can read it for you for free.

Let's see what you can find then we take it from there.