hey 2600I gurus heres a q for you

saw this one one another forumI recently got a 93 b2600i from my uncle for free. I got the truck started and it runs really great untill it gets warmed up. After about 20-30 mins it starts missing. It does it off and on only after its warmed up. (the temp guage says its normal temp but it seems really hot.) Could this be the start of an ecu problem? I already changed it once with one from the junkyard just to get it started. After the truck cools down its fine again. HELP?!?!?

it could be the water pump going out. have u change your temp sensor? to see how hot your motors getting!

Could be, that dayum computer causes all sorts of havok, LOL To check it out, take the computer appart and look at the black round copasitors on the board. If they are leaking, or look like they have gained some weight, its going bad and u will need to ship it off to get fixed or get a new one. I was doing them for about 150 each a while back.

Laterz
Phil

Edited: 11/21/2005 5:44:50 AM by BIGRIGZ

Edited: 11/21/2005 5:42:55 AM by BIGRIGZ

my guess is a blown head gasket, you should rent a loaner tool from AutoZone it's called a Cooling system pressure tester. It's for basically doing a compression test on your cooling system. It's quick and easy. You'll need the adaptor for a Mazda and they loan that adaptor as a seperate piece. Hook up the pressure tester to your radiator and take out all of your spark plugs, pump up the pressure tester to like 15lbs (check the sticker on your hood or rad. cap for lbs.) and let it sit for at least 10 mins. If the pressure drops the head gasket could be bad. check all radiator/heater hoses for leaks also.

after you have done the pressure test crank the truck over with the spark plugs out, I'm bettin water will come shooting out of the spark plug holes.

this test should only take 15mins and tell you if your head gasket is bad.

it's another whole story how a bad head gasket can run good cold then bad when the motor warms up.

plus, if it's a new truck to you, you should get a compression tester and test the compression while you're testing the cooling system.

just my opinion.

BTW how about posting your results up, if you test it.

I had the same problem and it was the computer, I've had to put two in it so far in 5 years. There are some capicators that blow. open the computer up and see if they are blown! You can't miss them, they will be burnt, Black! Mine now has a cracked head and does the same thing again! Hope this helps!

take the oil cap off after you have run it a while, if there is exhaust coming out the il cap hole, you have the number one killer of B2600i's, a cracked head. They all crack, some let coolant in the exhaust, some let exhaust in the coolant, some let oil in the coolant, some let exhaust in the oil. But they ALL crack. Should have been a recall, now the only solution is a used head (used heads are just cracked heads that havent cracked yet) or a new casting from the dealer that has the defect fixed and only costs NINE HUNDRED DOLLARS BARE.

pick up coil?

sounds like a cold start injector failure or mass air sensor failure! but a computer is a good chance also they are known for it! we have seen alot of them in the shop. i would also go buy a $20.00 temp gauge and hook it up to see if yours is reading right!

your head is warped its a common problem on those just get it milled and replace the head gasket

I had that exact same problem.......is the truck lowered?