Pre-Power Stroke Diesel (7.3L IDI & 6.9L) Diesel Topics Only

Starting problems 91 F350 7.3L Diesel

Thread Tools
 
Search this Thread
 
  #1  
Old 10-12-2013, 11:16 AM
nse1355's Avatar
nse1355
nse1355 is offline
Freshman User
Thread Starter
Join Date: Mar 2011
Posts: 28
Likes: 0
Received 0 Likes on 0 Posts
Starting problems 91 F350 7.3L Diesel

I thought I found a similar problem here but i can't find the answer anymore, please help.

I think there may be two problems...

1) I have to turn the key 100 times before it will start (possible fuel problem?). IF I'm lucky it will stay started but often it dies after about 5 seconds then I have to repeat the key turning process again. It has to crank for some time before it actually fires. If I'm not careful I have drained the batteries and had to charge them before attempting again.

2) the engine heater works and does make it eaiser to start but the whole leave the key turned for a few seconds to heat up the glow plugs doesn't work. The 'wait to start' light doesn't work. Possible glow plug or relay problem?

3) once it's heated up it will start with NO problems for about 4-5 hours but if it sits longer then again, the key turning ordeal.

It's been in the family since new and we lost track of the mileage after about 500,000. I want to get it dependable again.

Please help
 
  #2  
Old 10-12-2013, 11:31 AM
MT4x4guy's Avatar
MT4x4guy
MT4x4guy is offline
Senior User
Join Date: Nov 2012
Location: Montana
Posts: 180
Likes: 0
Received 0 Likes on 0 Posts
Sounds like you have a couple of problems, one is air intrusion, you have a leak in your fuel system somewhere that is allowing air in the lines, which is why it starts then quits.

Number 2 sounds like your glow plug controller is not working, or the relay is not functioning correctly, hence no glow plugs, nearly impossible to start if the GP's are not working.
 
  #3  
Old 10-12-2013, 11:41 AM
nse1355's Avatar
nse1355
nse1355 is offline
Freshman User
Thread Starter
Join Date: Mar 2011
Posts: 28
Likes: 0
Received 0 Likes on 0 Posts
Thank you

You confirmed what I was thinking...

I remember someone telling me to check the o-rings on the injectors. I got it started today and looked closely and there wasn't any fuel bubbleing out of the injectors. my brother has replaced some of the o-rings before and told me this is how you can tell if they're bad.

When he gave me the truck several years ago the key only needed to be turned about 15 times before it started.
 
  #4  
Old 10-12-2013, 12:12 PM
Forddiesel17's Avatar
Forddiesel17
Forddiesel17 is offline
Senior User
Join Date: Jan 2011
Location: Bluffton, IN
Posts: 271
Likes: 0
Received 0 Likes on 0 Posts
IF and that's a big if, the fuel system and glow plug system is in top notch condition you should only have to turn the key once. 100 times to me seems extremely excessive. You are waiting 2-3 mins between cranking right? You can' take out your starter if you aren't. I have an air intrusion problem in my truck too but never have had to crank more than three times. Replace your return lines and get the glow plugs functioning correctly and it should solve your problem. Read the glow plug sticky at the top to troubleshoot your glow plug problems.
 
  #5  
Old 10-12-2013, 12:47 PM
whiteboyslo's Avatar
whiteboyslo
whiteboyslo is offline
Posting Guru
Join Date: Jan 2001
Location: Poway, CA
Posts: 1,101
Likes: 0
Received 0 Likes on 0 Posts
Are you turning the key to the ON position that many times, or actually cranking it that many times? Turning the key to ON activates the glow plugs if the system is working, but if your light isn't coming on at all or it only flashes for a brief moment followed by a bunch of clicks, that isn't right. Means either you have dead glow plugs, a dead controller, or both.

Stalling after staring is likely air intrusion. I'd start with the return lines (replace the GPs at the same time if they're dead; it's easier) and go from there. When I bought mine, changing out the GPs and redoing the return lines (including o-rings and caps) took it from being a royal PITA to start to an absolute breeze. Starts on the first crank every time now.

Mike
 
  #6  
Old 10-12-2013, 01:08 PM
nse1355's Avatar
nse1355
nse1355 is offline
Freshman User
Thread Starter
Join Date: Mar 2011
Posts: 28
Likes: 0
Received 0 Likes on 0 Posts
Thank you both.

I'm turning the key 100 times to the on position which is supposed to activate the glow plugs but I'm sure they arn't working (plugs, relay, something). After 100 turns I'm then going all the way to the start position and it cranks.

I'm not sure if this is true but I've heard turning the key also activates the fuel pump so I was thinking if there's air in the line the 100 key turns is forcing the fuel through the lines which MIGHT explain why it has to crank for so long before it fires. Any thoughts on this becasue I'm baffeled why I have to turn the key so many times assuming it's not really doing anything for the glow plugs (like I mentioned, the engine heater does heat up the block and help it start).

I think when you turn the key you're supose to hear a clicking noise; I don't get that clicking noise.
 
  #7  
Old 10-12-2013, 01:11 PM
nse1355's Avatar
nse1355
nse1355 is offline
Freshman User
Thread Starter
Join Date: Mar 2011
Posts: 28
Likes: 0
Received 0 Likes on 0 Posts
I only use the front tank and was thinking about putting fuel in the rear tank and see if that has an affect.

???
 
  #8  
Old 10-12-2013, 01:28 PM
nse1355's Avatar
nse1355
nse1355 is offline
Freshman User
Thread Starter
Join Date: Mar 2011
Posts: 28
Likes: 0
Received 0 Likes on 0 Posts
My brother just told me it's a 1990. I had a 1991 F250 and a 1995 F SuperDuty (aka F450). I keep getting the years mixed up.
 
  #9  
Old 10-12-2013, 01:33 PM
nse1355's Avatar
nse1355
nse1355 is offline
Freshman User
Thread Starter
Join Date: Mar 2011
Posts: 28
Likes: 0
Received 0 Likes on 0 Posts
Reply to Forddiesel17...

No I wasn't waiting 2-3 minutes before trying to restart. I will now! Thank you.
<table border="0" cellSpacing="6" cellPadding="0" width="100%"><tbody><tr><td class="alt2"></td><td noWrap="nowrap">
</td></tr></tbody></table>
 
  #10  
Old 10-12-2013, 01:51 PM
MT4x4guy's Avatar
MT4x4guy
MT4x4guy is offline
Senior User
Join Date: Nov 2012
Location: Montana
Posts: 180
Likes: 0
Received 0 Likes on 0 Posts
If your GP controller is working, you should not have to turn the key so many times, now if you have air intrusion, turning the key on and off so many times is really not going to have much of an effect, because the leak is going to eventually pressurize and slowly bleed off, you are not going to force the air out until such time as you have the engine running and fuel flowing at 100%.

You really need to replace those return lines first, then go from there, it will make a big difference and give you a better direction to follow.
 
  #11  
Old 10-12-2013, 01:53 PM
bashby's Avatar
bashby
bashby is offline
Post Fiend
Join Date: Nov 2005
Location: Charles Town, W bygod Va
Posts: 7,437
Likes: 0
Received 3 Likes on 3 Posts
You need to get your glow plugs working, did you see the sticky threads about them at the top of the page?
https://www.ford-trucks.com/forums/9...le-system.html
 
  #12  
Old 10-12-2013, 01:58 PM
nse1355's Avatar
nse1355
nse1355 is offline
Freshman User
Thread Starter
Join Date: Mar 2011
Posts: 28
Likes: 0
Received 0 Likes on 0 Posts
Sorry for showing my ignorance... what sticky threads? I don't see them or I'm just missing them.

I did follow the link you just provided and am looking it over, thanks.
 
  #13  
Old 10-12-2013, 03:42 PM
bashby's Avatar
bashby
bashby is offline
Post Fiend
Join Date: Nov 2005
Location: Charles Town, W bygod Va
Posts: 7,437
Likes: 0
Received 3 Likes on 3 Posts
It isnt the best tutorial, someone needs to compile all the info and do an article. (No, I'm not volunteering) After you read that feel free to ask any questions that arise.
 
  #14  
Old 10-12-2013, 11:08 PM
whiteboyslo's Avatar
whiteboyslo
whiteboyslo is offline
Posting Guru
Join Date: Jan 2001
Location: Poway, CA
Posts: 1,101
Likes: 0
Received 0 Likes on 0 Posts
Unless someone has installed an aftermarket electric fuel pump in your truck, turning the key to the ON position is not going to do anything for you fuel-wise. The lift pump (the pump that sucks the fuel from the tanks and pushes it to the injection pump) is mechanical, meaning it only works when the engine is running.

That being said, plenty of folks have replaced their mechanical lift pump with an electric one. It's a great upgrade and could help with your starting issues from an air intrusion standpoint, though that's really more of a band-aid than anything else as far as that goes.

When your GP system is working properly, you should get one click from the solenoid, though to be honest, it's not always audible (at least in my truck). If you get multiple clicks combined with a very short WAIT TO START light, that usually indicates bad glow plugs. If you don't get any clicks, my money is on a bad GP solenoid, wiring, or some previous owner got in there and monkeyed around with something they shouldn't have.

Mike
 
  #15  
Old 10-13-2013, 08:07 AM
nse1355's Avatar
nse1355
nse1355 is offline
Freshman User
Thread Starter
Join Date: Mar 2011
Posts: 28
Likes: 0
Received 0 Likes on 0 Posts
Thank you. It is possible that my brother installed an electric fuel pump. I'll check with him.

I'm going to replace the GP's and relay. I'm also going to check the wiring. I'll revisit the fuel problem after the GP's are replaced.

Side note: squirrels chewed through 90% of the wiring harness at the wiring block so I repaired all the wires. The starting problem was the same before and after I repaired the wiring harness but everything else worked as it should after the repair. The smaller wires around the relay are somewhat brittle so I might as well put new ones on while I'm at it.
 


Quick Reply: Starting problems 91 F350 7.3L Diesel



All times are GMT -5. The time now is 06:20 AM.