Most common check engine causes
#1
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Most common check engine causes
On my 86 Toyota truck 4x4 w/2.4 EFI.check engine comes on more frequently now after evacuating the A/C..will finish charging it thursday.It stays on then goes off,dosen't flicker.Started out with just one light a day,now back and forth at any speed.No other lights flashing a warning.
#2
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What I see so far with a very limited knowledge of any mechanics.The coolant temp sensor? next to the green cold start injector time switch has bare wires going into the plug,wire coating gone.I looked there as that's right above the tight fitting A/C compressor and there were lot's of hands playing with the compressor.Also one spark plug wire was laying on the manifold heat shield.Whether any of this means anything I don't know but hopefully will find out thursday when my friends mechanic charges the A/C and looks for engine light symptoms.
#3
Registered User
The coolant temp sensor is the green one. The brown one is the time switch. If those wires are making contact.....shorting.......you're always or intermittently grounding the cold start injector. Not sure how much of an effect that'll have really considering the cold start injector only gets voltage when the key is in the start position.....turned all the way forward. But, still bare wires aren't a good thing......particularly when it is activated by voltage. You should atleast tape them up or something.
Something you should know........the CEL comes on when there's a diagnostic trouble code set meaning the ECU has detected a problem. It will come on solid. It won't flash a code, though, until you jump the testing terminals found on the yellow, two terminal plug above the driver's side fender well behind the airflow meter. That is if you have one, ie. it's not missing. You should have one, though. They do come from the factory like that. Anyway, you have to jump the two test terminals (T and E1 on these older Toyotas) with a paper clip or piece of wire to short the ECU EFI regulation and access the diagnostic/base timing function.
Something you should know........the CEL comes on when there's a diagnostic trouble code set meaning the ECU has detected a problem. It will come on solid. It won't flash a code, though, until you jump the testing terminals found on the yellow, two terminal plug above the driver's side fender well behind the airflow meter. That is if you have one, ie. it's not missing. You should have one, though. They do come from the factory like that. Anyway, you have to jump the two test terminals (T and E1 on these older Toyotas) with a paper clip or piece of wire to short the ECU EFI regulation and access the diagnostic/base timing function.
#4
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Thread Starter
thook.dark outside now so can't see what colors are what,but I know when facing the engine it's the one on the right with the bare wire(s) going into the switch/or sensor.
#5
Registered User
If you're certain it's the one on the right, then that's the coolant sensor. Better get them wires fixed. That's probably your code.
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steve miller
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10-10-2015 01:40 AM