# 7.3 turns but wont fire



## Maclawnco (Nov 21, 2002)

We parked this truck after saturday's storm with no indications of any engine issues. Plugged it in like we always do when its done. We went to bathe it yesterday to find it wont start. We kept it plugged in and hooked up a battery charger. It turns over just fine but has a very, very hard time firing. When it does, it jumps around rpms for 10-ish seconds (500-1000 rpms) then dies. Mechanic said maybe gelled fuel but I dont think so as our CTD start just fine and were fueled at the same place/time. Any ideas guys? TIA


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## goel (Nov 23, 2010)

First thing that comes to mind is a cam sensor. But I am not a mechanic, just a 7.3 owner. Replaced 2 on a truck so far.


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## Raymond S. (Jan 8, 2008)

Sounds like fuel. Just for kicks, throw a salamander heater on it to make sure it's getting heat. Also, are the glow plugs working? Could be glow plug relay.


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## MickiRig1 (Dec 5, 2003)

Got oil? Needs oil pressure to fire injectors. Cam sensors go bad all the time too.


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## jtslawncare (Nov 29, 2008)

yea I believe 500psi they need.. Id override the glow plug relay on top of motor with a screw driver for about 10-15 secs then have someone fire it..


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## 2COR517 (Oct 23, 2008)

Does thelug in heater work?

Do the glow plugs work?


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## dfd9 (Aug 18, 2010)

Cycle the glow plugs aboot 5 times. And leave it plugged in. If the battery is getting weak, throw a charger on it for 10 or so minutes.

I'm in the weak glow plug relay camp. 

Look into Trombetta for a replacement. B&B gave me the part number and I have never heard a negative word about Trombettas. In fact, I got sick of the cheapies from NAPA and switched all mine this fall.


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## Maclawnco (Nov 21, 2002)

The plug in works but I dont think the glow plugs work. Thx all for your help so far


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## dfd9 (Aug 18, 2010)

Can you get it towed or pushed inside?


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## snowyangel (Nov 8, 2012)

Mine runs rough as hell for 15 seconds if not plugged in, and has no power when on the pedal until its warmed up. Mechanic says it may be a sign that the HPOP is going to need replaced soon. He told me to just let it warm up good first.


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## Maclawnco (Nov 21, 2002)

the truck would take 10 or more glow plug cycles this fall to start if it wasnt plugged in. So, we keep it plugged in all the time now and it had been starting just fine as it did when we started it before saturdays storm. We parked it after that plow event and now it wont start. I dont have any heated space left inside; its all full of salt now. The mechanic is going to try the cam sensor. Hoping this works.


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## dfd9 (Aug 18, 2010)

Replace the glow plug relay first. 

It isn't the cam sensor. 

I guarantee it.


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## allagashpm (Sep 29, 2012)

Maclawnco;1554858 said:


> the truck would take 10 or more glow plug cycles this fall to start if it wasnt plugged in. So, we keep it plugged in all the time now and it had been starting just fine as it did when we started it before saturdays storm. We parked it after that plow event and now it wont start. I dont have any heated space left inside; its all full of salt now. The mechanic is going to try the cam sensor. Hoping this works.


if you had trouble this fall as well then it is the relay. Happened to mine last year, anything below 35 she would have a hard time starting, if at all. Now that the temps are lower it will give you more trouble.


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## clark lawn (Oct 7, 2005)

If you have it plugged in and the block heater is working then you don't need the glow plugs. Check your oil level, remove and inspect fuel filter. Could be a weak cam sensor, rare but does happen. Is you EWL on? When you turn the key on does the temp gauge go up some? Can you hear the lift pump running?


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## Milwaukee (Dec 28, 2007)

Check voltage on batteries do you see it drop down to 11 volt when turn on key for glow plug relay? Do you hear click from relay? If not I use biggest snowplow relay on mine no problem It was Trombetta for Boss snowplow.


Leave plug block heater for about 5 hours did it start or rough idle? Sound like injectors issues. Do you have someone with scanner they could look at ICP pressure and IPR duty when crank.


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## dfd9 (Aug 18, 2010)

clark lawn;1555412[B said:


> ]If you have it plugged in and the block heater is working then you don't need the glow plugs. [/B]Check your oil level, remove and inspect fuel filter. Could be a weak cam sensor, rare but does happen. Is you EWL on? When you turn the key on does the temp gauge go up some? Can you hear the lift pump running?


Horse hockey.

I have 4 7.3s. If the GPR is weak, they will not start no matter how long they've been plugged in and the temps are below 40ish.


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## clark lawn (Oct 7, 2005)

Well that shows how little you know. First a glow plug relay cannot be weak they either work or they don't. Second if it is plugged in and the block heater is working properly then the engine will already be warm soyou would not need a cold start assist( glow plugs). You do not need glow plugs to start or run a diesel. And for the record I have been a diesel mechanic for almost 20 years. What are your credentials?


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## dfd9 (Aug 18, 2010)

I slept at a Holiday Inn Express last night. 

OK, I used the wrong term about the GPR's. I have had numerous go out the last couple years. I replace them, cycle the glow plugs and the non-starting issue goes away. All have had the block heater plugged in. The block heaters are functioning. 

I never said a diesel requires glow plugs, I also have 3 Cummins. I do know the 7.3s need them though.


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## clark lawn (Oct 7, 2005)

If you have them plugged in and you still need the glow plugs to start then you have other issues going on. We get 444s in here all the time for the same issue and rarely does it end up being glow plugs or relay. A 444 is a 7.3 with a mechanical fuel pump whereas ford runs an electric pump.

I ran my 7.3 with a bad relay for almost 2 years because it was either parked in a heated garage or plugged in and it always started for me.


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## 2COR517 (Oct 23, 2008)

A 444 is a 7.3?


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## dfd9 (Aug 18, 2010)

2COR517;1555847 said:


> A 444 is a 7.3?


A 7.3 is a 444?


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## tjctransport (Nov 22, 2008)

a 7.3 IDI is the same engine as an International D 444. 
a 7.3 IDI turbo diesel is the same as an International DT 444.
a 7.3 powerstroke is the same engine as an International DT 444-E.
the main difference between International and Ford engines is the computer tune.


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## 2COR517 (Oct 23, 2008)

What's IDI?


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## dfd9 (Aug 18, 2010)

The first 3 letters of IDIot.


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## Plowtoy (Dec 15, 2001)

2COR517;1556021 said:


> What's IDI?


InDirect Injection, meaning that the fuel is not directly injected into the cylinder. Early 7.3s were IDI.


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## Maclawnco (Nov 21, 2002)

Back on topic guys... Just make my damn truck run


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## clark lawn (Oct 7, 2005)

Answer my questions and I can point you as to were to go.


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## dfd9 (Aug 18, 2010)

Already did. 

Spend $50-60 on a Trombetta and your problem will be solved.


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## clark lawn (Oct 7, 2005)

Where did he answer me? Again for the slow people if the block heater is working properly then the engine will start without the glow plugs. We had two in the shop today that did the same thing. Both if them put new GPRs on and the thing still didn't start. One needs a HPOP and the other was a fuse.


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## Milwaukee (Dec 28, 2007)

Maclawnco;1556128 said:


> Back on topic guys... Just make my damn truck run


Going ask couple questions

Is oil full?

Do you see oil gauge go up when crank?

Can u hear fuel pump when double cycle key switch?

Have you try plug block heater more than 5 hours do you see engine temp gauge up when on key? When I have bad glow plugs and relay I didn't need them if I plug no more than 3-4 hours.

Do you see smoke out exhaust when crank? White blue black grey?

Is engine seem to spin slow ? Is batteries terminals CLEAN of corrosion?

Can you hear Glow plug relay click when you turn key? If not replace with Boss snowplow relay it biggest relay. Do OHM test on glow plug's pin in valve cover connector.

Have truck running rough before? How many miles on it?

Find someone with scanner that can do injector buzz test and check oil ICP and IPR duty when crank?


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## dieselss (Jan 3, 2008)

Maclawnco;1556128 said:


> Back on topic guys... Just make my damn truck run


A. need more info

when you plug the tk in. feel around by the oil filter for the block heater cord. does it feel warm?? (need to ck for this when the tk is cold) this will tell you if the block heater is actually working.

ck the glow plug relay under the hood, pwr in the big terminal and when you turn the key pwr on the other big terminal.

when was the last time you changed the f.f.....and when was the last time you cleaned the garbage in the bottom of the bowl?

ck the oil as as mentioned. from experience,,if it's real low it wont start,,,or start real hard 
so,,,some homework,,then report back Thumbs Up


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## GSS LLC (Jul 7, 2012)

try a hit of ether? sometimes the hpop will get weak, but a whiff of ether makes it spin fast enough to start. i thought the hpops wouldnt start when up to temp because expansion makes the seals not tight enough, but cold they were fine? 

on the 6.0's there are pipes in the heads that feed oil to injectors, they have o rings that go bad.

check #18 and 21/22 fuses. make sure you have oil in the hpop reservore, check if white smoke comes out the exhaust upon cranking, that will tell you if you are getting fuel or not.check the ipr valve.

edit: make sure your batteries are good! weak batteries will cause the same issues.


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## clark lawn (Oct 7, 2005)

Do not use either. If it hit a glow plug or grid heater it will explode and possibly damage the engine and cause injury or death to you.


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## Milwaukee (Dec 28, 2007)

GSS LLC;1556288 said:


> try a hit of ether? sometimes the hpop will get weak, but a whiff of ether makes it spin fast enough to start. i thought the hpops wouldnt start when up to temp because expansion makes the seals not tight enough, but cold they were fine?
> 
> on the 6.0's there are pipes in the heads that feed oil to injectors, they have o rings that go bad.
> 
> ...


I suggested not use either or starter fluid they aren't safe for diesel. Just use brake cleaner can with label say flammable. It work for me.


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## GSS LLC (Jul 7, 2012)

worry warts. turn the key, wait for the wait to start light to go out so the glowplugs arent on, crank the engine while someone gives it a small whiff. thats the proper way to do it. people talk about things exploding because some ****** sprayed half a can in an engine and tried to start it.


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## Maclawnco (Nov 21, 2002)

Thanks so far all. Passing this topic to my mechanic. I dont do wrenches.


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## Milwaukee (Dec 28, 2007)

GSS LLC;1556320 said:


> worry warts. turn the key, wait for the wait to start light to go out so the glowplugs arent on, crank the engine while someone gives it a small whiff. thats the proper way to do it. people talk about things exploding because some ****** sprayed half a can in an engine and tried to start it.


WRONG they are actually stay on for 120 seconds after glow plug light on cluster went off.


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## 82F100SWB (Dec 12, 2004)

Pull one of the leads off of the relay if you are concerned. Like others say, if the glows are not functioning and it is actually cold out, it is not going to start, even if it is plugged in. Thats just how these things are. 
That said, it isn't starting after one glow cycle, there is something wrong. I can start my rather tired(26K hours, no major work ever) 96 on one wts cycle, even at -30. 
My last two gpr failures were intermittent for a month or two before they finally died.


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## clark lawn (Oct 7, 2005)

82F100SWB;1556529 said:


> Pull one of the leads off of the relay if you are concerned. Like others say, if the glows are not functioning and it is actually cold out, it is not going to start, even if it is plugged in. Thats just how these things are.
> That said, it isn't starting after one glow cycle, there is something wrong. I can start my rather tired(26K hours, no major work ever) 96 on one wts cycle, even at -30.
> My last two gpr failures were intermittent for a month or two before they finally died.


And another one that doesn't know what they are talking about.


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## dieselss (Jan 3, 2008)

Well let's wait and see what the mechanic has to say


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## diesel dave 04 (Nov 24, 2008)

GSS LLC;1556320 said:


> worry warts. turn the key, wait for the wait to start light to go out so the glowplugs arent on, crank the engine while someone gives it a small whiff. thats the proper way to do it. people talk about things exploding because some ****** sprayed half a can in an engine and tried to start it.


WRONG the glow plugs are still on even after the light goes off on a 7.3 powerstroke.


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## diesel dave 04 (Nov 24, 2008)

do you have any smoke when cranking?


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## rcn971 (Jan 28, 2011)

Read this damn thread the other day and today my truck wouldn't start....just cranks


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## goel (Nov 23, 2010)

Darn. A weekend now and no update in the status.


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## dieselss (Jan 3, 2008)

Well post another thread about it. And you'll get 20 pages of fixes lol.


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## rcn971 (Jan 28, 2011)

dieselss;1557641 said:


> Well post another thread about it. And you'll get 20 pages of fixes lol.


Haha....just going to check for fuel up top, and then get out the multimeter. I just a few months ago went crazy chasing down a bad injector. So I know that all the wiring harness' under the valve covers and IDM should all be good.


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## 2COR517 (Oct 23, 2008)

If we're talking ether, recently saw a rod through the side of a CAT C7. Not a straight pushrod in the engine.


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## Maclawnco (Nov 21, 2002)

We park on gravel so we didnt see the 10 quarts of oil it was short. Changed the CPS too as that code was in the computer. Full of oil it runs great with no apparent damage but oil drizzles out the pan we thought was succesfully patched. Now we get to replace the oil pan.


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## 2COR517 (Oct 23, 2008)

Horses, not Zebras....


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## dieselss (Jan 3, 2008)

well,,,,sometimes it takes a big pair to admit your miss step,,,,,thx for the update. get the pan fixed and you'll be off and running for a long time


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## goel (Nov 23, 2010)

Well that's not what I was expecting to hear. But easily resolved, do it right. Pull the motor and fix all the little things at the same time.


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## Maclawnco (Nov 21, 2002)

Yeah, 56k miles on it. Id like to think it could go another 12 years on one more pan.


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## dfd9 (Aug 18, 2010)

Crap, I was wwwwwwrrrrrrong. 

At least it didn't start. Saved some expense.


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## clark lawn (Oct 7, 2005)

Imagine that, a GPR wouldn't add 10 quarts of oil.


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## DIRISHMAN (Jul 30, 2010)

oh brother


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## Jim74 (Jul 8, 2012)

YouTube Damiendiesel1, he has a carbon oil pan cover so you don't have to pull the motor. I trust him completely, I had an oil leak that the mechanics at the company I work at said was a rear main seal, two thousand dollar fix, Damien found a bad o ring for around a three hundred dollar fix, he could have porked me but didn't.


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## MickiRig1 (Dec 5, 2003)

Everbody thought " Of course it has oil ! " 
It is hard to kill or no start a 7.3. Oil is one of the big ones!


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## dieselss (Jan 3, 2008)

3 of us Mick asked about the oil....the op never answered bout cking it but oh well stuff happens its up and running buy needs a pan


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## rcn971 (Jan 28, 2011)

Mine started up out of the blue...the next day. I am thinking the cam sensor is bad or going bad. No codes though. This one was never brought in under the recall for them.


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