302 efi problems
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302 efi problems
my van seems to run fine from a cold start for about 12-14 minutes and then it starts chuging,backfiring occasionally, will not idle it seems like not all of the cylinders are firing. then i let it sit for a couple hours to cool down completely and it runs fine for the 1`2-13 minutes and again... changed the fuelfilter, fuel pressure relief valve,cap, rotor ,plugs, wires, had a fuel injection cleaner done at a local shop(the one with the IV,gas and oil additives),added slick 50 gas treatment to both tanks. i was told by the mechanic that the fuel pump was fine.i don't understand why it runs so good for the first 12 minutes(the engine has reached operating temp in 4-5min) ???
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302 efi problems
A major thing that happens with a fuel injected car at about 10-15 minutes (give or take) is the system will go into closed loop. When it is cold, and the oxygen sensor is not up to approx 500-600 degrees, the engine operates in "open loop". The computer looks at the sensors to see what's going on, and then looks at a table of numbers in the memory so it can calculate how much fuel to deliver. After the oxygen sensor warms up, the computer goes into "closed loop", where instead of looking into the memory tables, it looks at what the oxygen sensor(s) are telling it, as far as lean/rich and then makes decision from this as far as fuel delivery. Has anybody you've taken it to, try to read any codes from the computer?
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302 efi problems
no, we haven't done that yet. should i buy one of those trouble coders, or just change the sensor?is the coder hard to use? I have a 86 econoline van, do you know where i need to hook the coder up or should i relax and read the instructions that come on the box or, gasp, look in my haynes manuel. boy that sounded dumb. thank you for your help.
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