1995 Toyota Tacoma While driving

Hi Blair1234,

Actually the ignition switch can cause the engine to buck and stall much like you have described, you don't need to replace the tumbler, just the switch portion. To be sure about the problem, attach a test light to the main outgoing feed wire to see if the power quits while the engine stalls. I have attached a diagram.

Please let me know how it goes,

Best, Ken

The engine doesn't actually stall I was just using that as a way to describe how it acts. Any other suggestions or should I still go with checking that?

Also engine light is on for catalyst efficiency bank 1.

Hey Blair1234,

The catalyst code will not cause the problem you have described. It still could be the ignition switch as the contacts wear they can intermittently cut power to the system which would make the engine buck. Can you please clear the codes drive it for a while, then check it again?

Best, Ken

I have also seen the fuel contamination can cause the engine to surge, when you replaced the fuel pump, did you look inside the tank for water?

Best, Ken

Tank looked fine, didn't have corrosion but when I replaced the filter it was defiantly clogged, the truck sat for 3 years before I got it, I was told by a local mechanic that it could be injectors. I have ran cleaners through the gas to try and clean it also.

O ya, the injectors being clogged can definitely cause the problem, I believe your engine has four of them. BTW they sometimes can cause the catalyst efficiency code as well.

I have ran cleaner through it a couple of times and a local shop said to run transmission fluid through it. Any suggestion on what to use or replace them or? its my DD so I cant have it not running

I have had zero luck with any type of cleaner working for me, if the injectors are the problem you will need to replace them, let me know.

Best, Ken