i have a maza b2500 truck im having troble with the motor turns off when engine get warm it takes about 20 min to start it when this happens someone please help me. i have change head, timing belt,sparkplugs and wires. i dont know if fuel relay going out or not

when you start it when cold does it idle normally?

yep

when you say turns off do you mean flat out turns off or slowly dies?

yes sir

turn off

i have to coast to side of the road but wait 10 mins or so it will start back up

ok fuel relay should be swap-able with another relay the same. that would be where i start first ( cheapest) second item would be fuel filter. have you tested your fuel pressure at your fuel rail?

no sir

how u test it

you need to own or borrow a fuel pressure tester. and there should be a little cap usually on the end of your fuel rail called a shraider valve and when you take the cap off it should almost look like a valve stem you put your fuel pressure tester on the end and turn your key on and asses the pressure and ensure its maintaining pressure i am attaching a link to help you out you want to see 56-72 psi or if you have a 3.0L flex fuel 55-75 and make sure it doesnt lose more then 5 psi https://www.youtube.com/watch?v=_oXLUqE4Sf0

im thinking either fuel relay or your pump is going out (overheating) how many miles on it and have you ever had a pump changed also try with a full tank of gas and see if it still does it as the pump uses the fuel to keep it cool. and do you get any service engine light on or security light and does your accessories stay on when it dies

to me it is showing signs of a bad pump it pushes the fuel on initial start up and runs the vehicle for a bit but then the pump overheats and quits and wont start again till it cools down. or the relay is heating up and doing sort of same thing. but a clogged fuel filter will also cause the pump to over pressurize and make it quit from working too hard.

thanks alot will try that thanks alot

If you have a b2600i I dont know of a shrader valve onthe fuel rail. However my best suggestion to you is to get a Haynes shop book and look under section 4 which is fuel and emissions and it tell you how to do it. If there is a harbor freight near you then you can pick up a tester fairly cheap. However, if you are not constantly working on cars i suggest renting one for a couple of hours. AutoZone, Oreiillys has a tool loan program. If where you live has none of these places, check with your local auto stores they may know where and how you can get a tester. The operable pressure should be no lower than 27 psi or no higher than 35 on a 90s b2600i.

Also. Your fuel pump relay is in the driver side kick panel. Remove it and start the truck its a yellow looking little box with a plug going to it. While the truck is idling touch it. Is it getting hot? If so replace it. Those are the only things i can suggest.