• Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

power stroke starting woes

bigblueox

Senior Member
Joined
Jun 1, 2007
Messages
348
Location
virginia
I purchased a 1997 350 4 door long bed 4x4 with the turbo 7.3 with automatic.
my problem is cold weather starting. after the truck sits for a while in the cold it will start up lope over once or twice and then die. After 3-4 times it will finally start. I cannot find where a block heater goes. Does anyone have any experience in this? also does anyone have any experience with the large remote mount oil filter that are supposed to last x number miles more? Any help will be greatly appreciated! ~zach
 

GOINGBROKE

Well-Known Member
Joined
Apr 28, 2007
Messages
85
Location
WYOMING
Occupation
Diesel shop owner - truck, farm and heavy equipmen
Block heater should be on right side in the rear of the oil cooler. Other things to check would be glow plugs, glow plug relay and cam sensor. With those all working should start ok. Don't know a thing about the remote oil filter
 

willie59

Administrator
Joined
Dec 21, 2008
Messages
13,361
Location
Knoxville TN
Occupation
Service Manager
Hmm, I have never had a problem with the OEM block heater being sufficient on 7.3 engines. Glow plugs have to work on them for sure, they won't hit a lick without them.
The block heater is located just above the oil filter, in the back of the oil cooler assembly.
 
Last edited:

farmerleach

Well-Known Member
Joined
Aug 28, 2009
Messages
58
Location
Canada
Is it possible to put a circulating blockheater in those things? They work so much better than just an element.

Yep, should be able to get one from any auto parts supplier. I have a 1000watt on my ranger, probably overkill on a 3 liter engine, but at -30 C or below it will be at full op temp in less than 45 minutes.
 

Muffler Bearing

Senior Member
Joined
Mar 26, 2009
Messages
512
Location
Colorful Colorado
Occupation
Truck Mechanic
the glow plug harness on those is a notoriously bad design, it's like a hard plastic frame bolted under the valve covers that develops open circuits. Also while you have the valve cover off, you can use a continuity tester to check each glow plug,
 

Steve Frazier

Founder
Staff member
Joined
Oct 30, 2003
Messages
6,599
Location
LaGrangeville, N.Y.
I've had 4 of the 7.3s and one does what I think you are describing here. When it starts in very cold weather, it lopes like a Detroit does when it's cold, often stalling one or two times before it smooths out and idles normally. I have a theory that it is something to do with the HPOP system for the injectors, the cold oil must have trouble reaching the pump to fire the injectors. When I have the truck plugged in, it doesn't happen. I run Rotella T 15/40 year round because it's readily available locally. I lighter oil for the winter might solve the problem too.
 

Hardline

Senior Member
Joined
Nov 29, 2009
Messages
340
Location
Waxahachie Texas
Occupation
Small business owner
On the 7.3 there are valve cover gasket on these trucks which have the electrical connections for the glow plugs and the injectors that go through the valve covers. Each cover has two plugs. The connector in the end of each plug is the connector that goes to each glow plug. You can ohm out each glow plug through the valve cover gasket and test each glow plug. Each should ohm out about .5 ohms. If all check out check the glow plug relay. It is mounted next to the fuel filter housing. Make sure that all of the voltage is passing through it. They go bad alot. Also to let you know. These glow plugs stay on after the light in the dash goes out. Even after you start the truck they can stay on while the truck is running for up to two minutes. So if it is really cold I will let the truck sit for about 15 seconds after the wait to start light goes out and then start. JJ
 

bigblueox

Senior Member
Joined
Jun 1, 2007
Messages
348
Location
virginia
I've had 4 of the 7.3s and one does what I think you are describing here. When it starts in very cold weather, it lopes like a Detroit does when it's cold, often stalling one or two times before it smooths out and idles normally. I have a theory that it is something to do with the HPOP system for the injectors, the cold oil must have trouble reaching the pump to fire the injectors. When I have the truck plugged in, it doesn't happen. I run Rotella T 15/40 year round because it's readily available locally. I lighter oil for the winter might solve the problem too.

Yeah i'm kinda inclined to believe this might be the case here. It seems like it a fuel problem not a heat problem. The reason i say this is it will reliably fire after only two or three revolutions. will lope hard like you say and then die. since injectors are fired from oil pressure do you think the oil pump could be going out or maybe trash in the pickup. i know in the High Pro world of diesel several companies offer "hotrod" oil pumps for the 7.3l. I wonder how well it would start with something like that?~zach
 

Steve Frazier

Founder
Staff member
Joined
Oct 30, 2003
Messages
6,599
Location
LaGrangeville, N.Y.
My truck has been doing this for at least 4 years now, if it was going to be a terminal problem i think it would have gone down by now. I haven't really investigated it to far, and I know very little about the injection system other than it uses high pressure oil and electric impulses to fire the injectors. I've wondered there might be a spec of dirt allowing the oil in the HPOP to drain back and have to build up again before the truck can run correctly. With thick cold oil this would take a few seconds longer than with warmer oil. From what I've heard the HPOP is pretty expensive.
 

willie59

Administrator
Joined
Dec 21, 2008
Messages
13,361
Location
Knoxville TN
Occupation
Service Manager
There's an oil pressure regulator solenoid on that system. I wonder if it is causing a problem? They usually just fail, though, and cause the engine to not run.

I don't know if it's the cause of the problem you fellows are having, but there is a gizmo bolted onto the driver side of the fuel filter pot. Has maybe 2 screws mounting it to the pot on the side just below the pot lid. If you remove that component, you'll find a screen where it connects to the filter pot. I've seen plenty of those screens clogged. I just don't know if it's causing your problem. :beatsme
 

7.3 Rocket

Member
Joined
Sep 20, 2009
Messages
5
Location
CT
Try a 5w40 on your next oil change rather than a 15-40. The reason I'm disinclined to believe it is the hpo reason draining down is that it fires and runs but then quits. Were it the hpo system draining down you would notice excessive crank times before it started then it would be ok.

I'd suggest changing your oil to a 5w40, changing your fuel filter if it hasn't been done recently, and checking your glow plugs.
 

Copenhagen

Well-Known Member
Joined
Jun 12, 2006
Messages
230
Location
Colorado
Idle lope is typically caused by oil that is too thick for the temps. I can almost guarantee that the lighter weight oil will solve your problems.

There are quite a few Ford truck forums. Join one and type in "idle lope" in the search.
 

Preppypyro

Well-Known Member
Joined
Nov 19, 2007
Messages
246
Location
Saskatoon, Sk.
You should change your oil to a synthetic oil, up here I use 0-40. You want to find the block heater cord, or if you dont have a block heater, install one, it makes life so much easier.

Here at minus 30C if I start my truck without it being plugged in, it does the same thing that you are talking about. Glow plugs and GPR work fine, its just sometimes too damn cold!

You can also install a light and a switch for your glow plugs, so you can turn them on and off when you want, and see when they are on and working.
 

absolutediesel

Active Member
Joined
Jan 25, 2010
Messages
35
Location
Chicago ,IL
check your hi psi system, sounds like an injector o-ring taking a crap........leaks when cold and when warm(like when block heater used ) does not leak, with a scan tool check the duty cycle % on the IPR .......if its over 35-40% you have a hi psi oil leak

you can check each head seperately by taking off hi psi feed line from hpop and using air psi to pressurize each head, if you hear a bubbling sound under valve cover you have a bad inj o-ring
 

classictruckman

Senior Member
Joined
Jan 1, 2010
Messages
250
Location
Ottawa Valley Ontario, Canada
Occupation
Tree Climber/339A Crane Operator
There's an oil pressure regulator solenoid on that system. I wonder if it is causing a problem? They usually just fail, though, and cause the engine to not run.

I don't know if it's the cause of the problem you fellows are having, but there is a gizmo bolted onto the driver side of the fuel filter pot. Has maybe 2 screws mounting it to the pot on the side just below the pot lid. If you remove that component, you'll find a screen where it connects to the filter pot. I've seen plenty of those screens clogged. I just don't know if it's causing your problem. :beatsme

I had a problem with my 7.3L last year that sounds alot like his, I'm not sure what exactly caused the problem, but I think it had to do with the oil pressure regulator solenoid. I changed the oil and the problem started(didn't associate the two) talked to a bunch of people who gave me lots of ideas, then changed the oil at the next interval and the problem went away.
 

Autocar

Senior Member
Joined
Dec 20, 2009
Messages
261
Location
ohio
Been having the same problem sence January I checked the the glow plug relay [looked like any 12 volt solenoid on older starters ] Called the shop about one $79.00 so I figured that was a stupid price so I went with the synthetic 5W40 at $19.80 a gallion which is also a stupid price. Just my opinion. After nice weather gets here I will tear the top off and check everything else under the valve covers.
 
Top