I just installed a rebuilt engine in my pickup about 2 weeks ago and have been scratching my head ever since because it will not start. I think it has something to do with not getting any fuel, I know my pumps in both tanks are working and there is good fuel pressure all the way up to the injector fuel rail but I do not think my injectors are "pulsing". I can only access the #1 injector connector because of the huge gigantic air intake in the way. Anyway, when the engine is cranking, I can put a test light on the connector and the light lights up in both pins, but when I put a volt meter on the pins, I am not reading any voltage. I have checked all of my sensors that input into the EEC IV and the sensors test fine. Is there something screwed up internally in the EEC that is telling the computer NOT to send a good enough signal to the injectors to "pulse" ? Also, I keep on reading about a crank sensor that tells the EEC to vary the rate of puls to my injectors. I swear up and down I do not have a crank sensor so where else would I be getting the signal from? Please help
The crank sensor is the PIP (profile ignition pickup) in the distributor. You cannot randomly assign #1 on an EFI engine for that reason. #1 should be marked on the distributor cap andit must be that one which is connected to plug #1. None of that is likely to explain your failure to start though unless you're 180° out. are you sure that the rotor is pointing to #1 on the compression stroke?
Sounds like the computer is not getting power or ground. There should be a smaller ground that goes directly to the battery post - make sure that is connected (it's the ECU ground). I'm not sure how the ECU gets +12V, you may want to check that on a schematic.
I have checked the timing a thousand times and today 1001. I did mis speak about the power at the injector connector. I am getting 12 volts to both pins with key on and engine not cranking, I am also getting 12 volts to both pins with key on and engine cranking. I do have a schematic and I am getting 12 volts to the computer. So my question now is, when then there is 12 volts at the connector on both pins, that is not right is it? And, is the injector normally open with power or is it normally closed with power ? Thanks for the responses.
Voltage is always supplied to the injectors when the key is on, including cranking. The ECM sends a signal to ground them when it wants them to squirt, so to speak. I've never tried using a DMM to confirm the signal, I always use noid lights, but if your DMM responds fast enough, you should see a pulsing signal when the engine is cranking.
Well, several days later I found the problem and it started right up. The 2 wires that fed the ground to start pulsing the injectors. The sheilding was melted. I suppose when I was monkeying around with the harness when installing the engine that I disturbed them enough to make em touch. I am not a good electrical guy so I feel pretty good that whatever it was works now. I sure appreciate the comments and suggestions guys, Have a good one.
92 f150 4.9 liter 300 6 won't start
Linear Mode
