my 1997 f150 4.6L v8 4wd was running great. I drove it about 40 miles running errands stopping twice, once to put gas in it. I returned home and parked it for about an hour and then restarted it to move it around the house to unload. I then restarted it and parked it in the driveway. The following day I jumped in to take another trip and it would not start. It would turn over but would not hit. I did some crude investigating (depressed the relief valve on the fuel rail) and decided that the fuel pump needed to be replaced. Picked one up at the junk yard and swapped it out and no results. I borrowed a fuel pressure gage and it registers 40psi. I have since removed a spark plug wire and it seems that there is no fire. (Used a screwdriver to try to get spark to ground). I am getting really frustrated with the complexity of this vehicle and need to know where to go from here. Any assistance would be appreciated.
P.S. I also looked into the oil fill cap on the valve cover just to make sure that the timing chain/belt (i dont know which it has since it appears to have dual overhead cams) was not broken. When cranking the engine I can see movement within the valve cover. Like I said it appears to have dual overhead cams since what I am seeing seems to be the end of a camshaft rotating
March, 24, 2009 AT 8:12 AM
First thing to check is fuses, under the hood, any marked IGN or EEC. If all good, check for power at the coil (+) terminal.
March, 25, 2009 AT 6:11 PM
OK. I have checked all of the fuses that I can find. Which brings me to my next question. Are there not any fuses inside the cab of the truck? The only fuses that I could find are under the hood on the drivers side. There are some really big ones and some tiny ones too. I removed and looked at all of them and they appear to be good. It just seems odd to me that there are none to be found under the dash somewhere.
I assume that by coil you mean the coil packs since there is no standard coil/distributor and when you say to check for power at the coil should there be power to them at all times when the switch is on or only when I attempt to crank the engine?
March, 26, 2009 AT 6:48 AM
COMPUTERIZED ENGINE CONTROLS POWERTRAIN CONTROL MODULE (PCM) Ground Circuits 1. Using a DVOM, check for continuity to ground at PCM connector terminals No. 24, 25, 51, 76, 77 and 103. See Fig. 1 . Resistance should be approximately zero ohms. If resistance is not approximately zero ohms, repair circuit open to ground. 2. Touch negative lead of voltmeter to a good ground. With vehicle running, backprobe positive lead of voltmeter to each ground terminal. Voltmeter should indicate less than one volt. If reading is greater than one volt, check for open, corrosion or loose connection on ground lead. Power Circuits Turn ignition off. Using a voltmeter, check for battery voltage between ground and PCM terminal No. 55 (KAPWR). Turn ignition to START or RUN position. Check for battery voltage between ground and PCM connector terminals No. 71 and 97. If battery voltage is not present, power is not being supplied from EEC power relay. See CIRCUIT TEST B in TESTS W/CODES - 4.6L article. PCM LOCATIONS Fig. 1: Identifying PCM 104-Pin Connector Terminals Model Location Pickup Right Side Of Engine Compartment Page 1 of 1 SYSTEM/COMPONENT TESTS - 4.6L -1997 Ford Pickup F150 3/26/2009 src="http://www.2carpros.com/forum/automotive_pictures/62217_f150pcm_1.jpg" alt="http://www.2carpros.com/forum/automotive_pictures/62217_f150pcm_1.jpg" />
Check fuse # 20 inside the cab its for the PCM and GEM and fuse # 30, its for the coils. Fuse box is under left side of the dash.