DJs74
Bronco Guru
- Joined
- Apr 1, 2014
- Messages
- 1,135
Hoping the EFI gurus can shed some light... trying to help my brother-in-law with his 1986 F250 project
► 302
► 4 speed
► EFI
► all factory electronic and fuel components
► single tank / not dual
Brother-in-law purchased an '86 F250 that ran but needed some body work and some general maintenance. He drove it a few times just beating around in it to get the feel and to evaluate things. He had a set of shorty headers from a past purchase and decided to install them... he removed the stock manifolds but removed nor unhooked any wiring except the battery cables and the starter cable bracket that was fastened to one of the manifold studs.
After the header install, it would not start... a friend of his told him to replace the module on the distributor (not sure how he knew/ why he thought that or suggested it because I hadn't gotten involved just yet), so in order to get the module off, he had to pull the distributor, replaced the module, reinstalled and still no start - that's when he called me.
We went through some trouble shooting by phone - was anything unhooked, if it had fuel, if he by any chance bumped into anything possibly tripping the inertia switch, etc. - answers revealed nothing obvious so I met him to take a look.
Problem #1 was the firing order was slightly wrong and wires were setup to fire CW (he is new to turning wrenches) so we took care of that but still no start. The coil is getting and sending fire to the distributor and plugs are getting fire.
Next, and here is where I'm not sure what is supposed to be happening and what feeds what electrically... the fuel pump makes no noise (no buzz, hum, priming noise) when the key is turned to 'on' prior to cranking. According to the literature I looked up online, it appears there are two pumps - one in the tank and one on the frame rail - not sure why or how all that works either but they are both there and neither seem to be doing anything.
Here is something that might be important but strange, at least to me anyway... after I reinstalled the distributor and rewired the plug wires, I stayed at the distributor while my BIL was at the key - I told him to try to start it while I worked the distributor and as mentioned earlier, it did not start but I kept hearing a clicking noise when I rotated the distributor (key on / not cranking the engine). When I rotated the distributor CCW, the clicking was coming from around the master cylinder area and when I rotated it back CW, I could here a clicking coming from somewhere under the intake plenum - it clicks every time, not sporadic or once in a while but with every rotation back and forth.
So, I started trying the track down the click, at the master cylinder area, I found the fuel pump replay (yellow square box with green connector). I cannot find the specific part that is clicking under the intake.
So, does anyone know if the relay clicking is normal or indicating the problem? What would the other clicking noise be coming from under the intake? Should there be an initial priming noise at the pump, humming, something / anything with the key on? How do the two pumps work / tie together? What mechanism causes the injectors to activate? Does each pump have its own relay or just one relay for both pumps? How to electrically test the relay(s)? I can only find one relay but there could be another hidden I suppose. I checked all the fuses under the driver side dash and they are all OK - not sure if there is a fuse for the pumps in addition to the relay? The inertia switch is located on the passenger side, in the cab next to the heater duct - there is a white button on top and it is down... could it be part of the problem? anyway to test it or manually trip / reset?
Sorry so long, trying to give as much information as I've learned so far and not sure what the next move should be. At the moment, I am thinking either one of the pumps are bad or maybe there is something preventing the one or both pumps from getting power. Don't understand the clicking. The truck ran prior to the header install and according to my BIL, he did nothing electrically other than the battery cables and distributor module.
Thanks for any information or things to look for and try. Let me know if you need to know anything else, I will be going back over to try again Monday evening but can get more information tomorrow if necessary.
DJs74
► 302
► 4 speed
► EFI
► all factory electronic and fuel components
► single tank / not dual
Brother-in-law purchased an '86 F250 that ran but needed some body work and some general maintenance. He drove it a few times just beating around in it to get the feel and to evaluate things. He had a set of shorty headers from a past purchase and decided to install them... he removed the stock manifolds but removed nor unhooked any wiring except the battery cables and the starter cable bracket that was fastened to one of the manifold studs.
After the header install, it would not start... a friend of his told him to replace the module on the distributor (not sure how he knew/ why he thought that or suggested it because I hadn't gotten involved just yet), so in order to get the module off, he had to pull the distributor, replaced the module, reinstalled and still no start - that's when he called me.
We went through some trouble shooting by phone - was anything unhooked, if it had fuel, if he by any chance bumped into anything possibly tripping the inertia switch, etc. - answers revealed nothing obvious so I met him to take a look.
Problem #1 was the firing order was slightly wrong and wires were setup to fire CW (he is new to turning wrenches) so we took care of that but still no start. The coil is getting and sending fire to the distributor and plugs are getting fire.
Next, and here is where I'm not sure what is supposed to be happening and what feeds what electrically... the fuel pump makes no noise (no buzz, hum, priming noise) when the key is turned to 'on' prior to cranking. According to the literature I looked up online, it appears there are two pumps - one in the tank and one on the frame rail - not sure why or how all that works either but they are both there and neither seem to be doing anything.
Here is something that might be important but strange, at least to me anyway... after I reinstalled the distributor and rewired the plug wires, I stayed at the distributor while my BIL was at the key - I told him to try to start it while I worked the distributor and as mentioned earlier, it did not start but I kept hearing a clicking noise when I rotated the distributor (key on / not cranking the engine). When I rotated the distributor CCW, the clicking was coming from around the master cylinder area and when I rotated it back CW, I could here a clicking coming from somewhere under the intake plenum - it clicks every time, not sporadic or once in a while but with every rotation back and forth.
So, I started trying the track down the click, at the master cylinder area, I found the fuel pump replay (yellow square box with green connector). I cannot find the specific part that is clicking under the intake.
So, does anyone know if the relay clicking is normal or indicating the problem? What would the other clicking noise be coming from under the intake? Should there be an initial priming noise at the pump, humming, something / anything with the key on? How do the two pumps work / tie together? What mechanism causes the injectors to activate? Does each pump have its own relay or just one relay for both pumps? How to electrically test the relay(s)? I can only find one relay but there could be another hidden I suppose. I checked all the fuses under the driver side dash and they are all OK - not sure if there is a fuse for the pumps in addition to the relay? The inertia switch is located on the passenger side, in the cab next to the heater duct - there is a white button on top and it is down... could it be part of the problem? anyway to test it or manually trip / reset?
Sorry so long, trying to give as much information as I've learned so far and not sure what the next move should be. At the moment, I am thinking either one of the pumps are bad or maybe there is something preventing the one or both pumps from getting power. Don't understand the clicking. The truck ran prior to the header install and according to my BIL, he did nothing electrically other than the battery cables and distributor module.
Thanks for any information or things to look for and try. Let me know if you need to know anything else, I will be going back over to try again Monday evening but can get more information tomorrow if necessary.
DJs74