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I have a 1990 Kodiak with the 7.0L TBI, air brakes as it is a dump truck. I'm the mechanic at our company, heavy truck/equipment to be exact, but I pretty much know how to work on everything. The truck was out working with the crew when the boss called me saying the alternator gauge was pegged out and it had a funny smell from the battery (Which we all know is an overcharging alternator). I explained what was going on and instructed him to unhook the wire from the alternator until they are able to get it in, as they were almost done for the day. I also told him that he would need to keep an eye on the battery gauge and hook the alternator up periodically if need be. I received another call saying the driver had run it until it died and the boss said he would go put an alternator on and a new battery. The truck comes in later on a wrecker. The battery and alternator were installed by my boss but it would not start. Upon further diagnosis the distributor had crapped out. I don't know if the bad alternator had caused this or what, because the truck ran fine up until then. So I went ahead and replaced the distributor, plugs and wires. The truck then started and ran. I disconnected the tan and black wire on the firewall that advances the distributor per factory recommendations, and set the base timing to 4 degrees BTC per the sticker on the air breather.

The issue I'm having now is when the truck is first started it will backfire out of the exhaust until warm then it runs fine. If I give it fuel when its backfiring it sound rough but revs up and continues backfiring. Once it is warm (after say 1-2 minutes on a fairly warm day) it runs like there was no issue at all. The colder the longer it takes. I know I'm dealing with a over fueling issue before the fuel system goes into a closed loop operation. So the question is has any of you ran into this similar situation? Maybe the over charging alternator fried a sensor or ECM. I was thinking maybe a coolant temp sensor because that is one of the sensors the ECM relies on when the fueling is in a open loop operation. Vacuum leak? Faulty injector? Let me know if there is anything I may be over looking.

Any help is greatly appreciated! Thank you in advance!
 
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