zuk88
Well-Known Member
If the block heater is plugged in it only takes one cycle of the glow plugs to start but other wise it takes 4 to 6 cycles, any suggestions? Glow plugs or controller?
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Help Support Hardline Crawlers :
96 Ford 7.3 hard start
- Thread starter zuk88
- Start date
the glow plug wiring harness on one of the sides rubs on the covers and then the glow plugs on that side quit working making it hard to start. ford has an updated harness. If you have a multimeter (clamp current measuring device) that can check to see if you have current through the wire. no current no worky... This is what the issue was on mine with some state you are talking about... I am a 2000 superduty 7.3.
hlb3
Zombie Hunter
When I had that problem it was a combination of bad glow plugs on one side a melted plug/valve cover gasket on the other side.
You can test resistance to the glow plugs with a multi-meter, just unplug the harness from the valve cover and test the pins, which is where I would start.
You can test resistance to the glow plugs with a multi-meter, just unplug the harness from the valve cover and test the pins, which is where I would start.
zuk88
Well-Known Member
Thanks guys, I'll start with testing the harness first.
zukkev
Cornfuzzled yet again...
2nd gens are more susseptible to the wiring issue like scott mentioned...1st gens like yours are more susseptible to the melted harness and glow plug issue like les mentioned... could also be the glow plug relay...
zukkev
Cornfuzzled yet again...
Easy way to check relay is to test if power is getting through from the heavy single lead to the twin smaller leads on the other side with the relayed triggered...
zuk88
Well-Known Member
Good to know....
zuk88
Well-Known Member
I take it that the relay is located near the fuse block under the hood on the drivers side?
zukkev
Cornfuzzled yet again...
Nope...on top of passenger side valve cover...looks like an old ford startre relay...:redneck: the might be two next to each other.. it should be the forward one.
zukkev
Cornfuzzled yet again...
Flip open the fuel filter access door if the top engine cover is there...
hlb3
Zombie Hunter
Here is a good write up, this is for a Super Duty, but the process is the same.
http://www.dfuser.com/Install Guides/How to check for a bad Glow Plug Relay.pdf
The only difference is the OBS has two 5-pin plugs per side instead of one 9-pin plug. The outside 2 pins on each plug are for the glow plugs, the middle 3 are the injectors.
http://www.dfuser.com/Install Guides/How to check for a bad Glow Plug Relay.pdf
The only difference is the OBS has two 5-pin plugs per side instead of one 9-pin plug. The outside 2 pins on each plug are for the glow plugs, the middle 3 are the injectors.
zukkev
Cornfuzzled yet again...
I have had countless relays click, yet not provide any power to the glowplug side of the relay...Best bet is to check power at the load side (glow plug side) of the relay with it energized...If you have an amp clamp, you can check the amp draw of the glow plugs on each bank...each plug should initially draw somewhere in the 20A range and drop as the plugs heat up...so, you should see somewhere in the vicinity of 160+ amps draw on the entire circuit, if you are getting 140 in initial kick, or 120, or 80...then you have a problem! :redneck:
zuk88
Well-Known Member
I dont have an amp clamp.
zuk88
Well-Known Member
A good place to start, thanks for the link.
zuk88
Well-Known Member
I'll definitely check the relay before anything else :awesomework:
hlb3
Zombie Hunter
When I was having issues, my relay was still working, but it was on the lower side of the "normal" range. I swapped it out just for piece of mind since it wasn't that much.
If you do need to swap out the glow plugs, at the time Rock Auto had very good prices on Motorcraft glow plugs, they were around the same price or cheaper than aftermarket ones, so you may want to check them out. Riff Raff down in Oregon is a good place to check too, I got my replacement valve cover gasket/harness from them since they were one of the cheapest places and they were close by (didn't realize I needed them until I tore into the engine).
If you do need to swap out the glow plugs, at the time Rock Auto had very good prices on Motorcraft glow plugs, they were around the same price or cheaper than aftermarket ones, so you may want to check them out. Riff Raff down in Oregon is a good place to check too, I got my replacement valve cover gasket/harness from them since they were one of the cheapest places and they were close by (didn't realize I needed them until I tore into the engine).
zuk88
Well-Known Member
The valve cover gasket is part of the wiring harness? :haha:
hlb3
Zombie Hunter
skinny_pedal
Well-Known Member
Just always build a fire in front of it. She'll start everytime:flipoff:
And I knew a guy that would do that when hunting/camping. Or that pig wouldn't start
And I knew a guy that would do that when hunting/camping. Or that pig wouldn't start
junkyard jim
Well-Known Member
Get someone with Ford diesel tech knowledge to check the injector pump timing as well. Had that problem with a 200,000 mile '91 E350 7.3 and they said the motor was just worn out. Tech guy at the RV shop dialed it in for $250 and it started like a dream with more power and better fuel economy ever since. (shop truck that everyone abused and I was the only one that checked oil, etc)
