I, first post 1989 3.ol 4x4 pickup no spark after running about 20-30 mins. when truck dose start CEL works , when truck dies no CEL and no spark from coil replaced ignitor , checked grounds , dist. ohmed ok , did tap test on coil and I get test light flashing on ground side to pos. will set for about an hour and then the CEL (CHECK ENGINE LIGHT) WILL BE BACK ON help...

 

Check the efi fuse terminals. Make sure the fuse fits tight and the terminals are clean.

 

checked , replaced fuse, ran extra grounds and cleaned mount to coil

 

No check engine light tells me there is a power issue with the ecu. I would start by checking for power and ground at the ecu while the problem is occurring.

 

efi relay dose get hot when running, can pull fuses when the truck will state and I ear stuff clicking when the cel is not lighting up nothing makes a noise

 

have power and ground at ecm

 

new coil,efi relay and ignigter still no start, anyone have a diagram of ecm ?

 

Ok kids after pinning and testing ecm found no signal from MAF, walked around truck found my best tool ( my hammer) and smacked the MAF / CEL CAME ON ! TRUCK STARTED FEEL DUMB NOW must find MAF the search is on thanks for the help great web site

 

may sound stupid but I've got a 89 v6 ext cab deluxe with similar problem...what is a "MAF" ?

 

"MAF" Mass Airflow Sensor.

 

it is part of the air filter cover. it cost about $ 200 from napa with core charge, when you remove it from the cover remember to check the new one out before you leave the store may have to remove the studs from the old one.

 

Thanks guys but "been there, done that"... Replaced fuel pump, fuel filter, MAF, 2 Ignitors, plugs wires, rotar button, Entire distributor, TPS. Finally replaced entire engine but problem still remains although not as pronounced...Still need ideas...

 

What are you symptoms?