hard or no start with a p1670

[Dzchey21]

I need to re-do the buzz test cold because last time i did it when it was already running smooth.

Not sure on how old anything is on the truck to be honest. THe owner hasnt had it long.

Ill do that on the hpop

truck is a 2000

 

[lincolnlocker]

Stock original injectors and o rings? Check battery voltage before you hit the key and then start the truck and see what battery/alternator voltage is during warmup and after its ran and smooth running...when the voltage reg starts going out in in my dually it sounds like its ****ty tuned pissed off till I burp the throttle to get the alternator to come back to life... may have said it already but does the gp relay check out?

live life full throttle....
load it like a box car, drive it like a stock car..

 

[Dzchey21]

yep relay checks out, even bypassed with jumpercables with no change.

Raising the rpm doesnt help anything, it flat just takes 10 min to get it to run smooth if its hard to start

It could have org injectors and o-rings im not sure tho.


What kills me is it can be 0 degrees and start fine sometimes but if it sits too long it wont start at 70 degrees

 

[lincolnlocker]

Id say with 244k on the ole girl, its time for a freshened up set of inj or orings.. my 01 does this exact same thing when its under 50°..

live life full throttle....
load it like a box car, drive it like a stock car..

 

[Dzchey21]

well so far nothing to report, went and got the truck, it was hart to start, took 15 sec of cranking and then ran rough for a good 2 miles.

truck has been sitting in my driveway for a week, without issue, its started every time

I have done a buzz test before starting every time, and everytime it sounds good and starts up. Wonder if i should NOT do the buzz test and see if it will start next time?

Getting frustrated

 

[Chvyrkr]

For what it's worth, I've started a good running 7.3 at below zero with no GP relay. It wasn't all that happy about it but it started, 5-10 seconds, ran smooth after maybe 15-30 seconds.

So, don't spend money on the glow plugs just yet.

And the IDM is in the drivers fender, basically behind the Fseries badge. So I doubt engine heat affects it.

I'd vote injectors/injector o-rings.

The longer you crank, the higher ICP should get, the more IPR DC you should see, as I recall.

I disconnected the IDM on my 02 once when I was lookin for a bent valve, and while I was crankin over with a buddy watching under the VC's, I got to 2000 +/- ICP in about 20-30 seconds.

If you're not seeing that, something's leaking, or not making pressure. IPR, HPOP, injectors.

 

[Dzchey21]

i already put GPs in the truck originally it had 3 bad


I can get icp quick even when it wont start.

 

[Chvyrkr]

When it won't start, does ICP cap at 500 or keep building slowly as you crank?

 

[TurboM700]

What's coolant temp reading? Just ran into this issue a few weeks ago (first cold spell here) truck would read negative -30 degrees causing starting issues and rough running till it was running for 10 mins. You could watch on the scanner the coolant temp go from -30 to 90 and the truck would just run fine. It was like clock work

Installed a new coolant temp sensor and its running fine.

Just an Idea.

Mike

 

[Chvyrkr]

Coolant temp readout through the PCM is inaccurate on 7.3's.

 

[golfer]

Dz- see if these symptoms are consistent with yours.

http://swampsdiesel.com/files/7.3LInjectorDiagnostic.pdf

 

[Southmike]

Dz- see if these symptoms are consistent with yours.

http://swampsdiesel.com/files/7.3LInjectorDiagnostic.pdf

the more I read that the more I cringe knowing I need new injectors...

 

[lincolnlocker]

Coolant temp readout through the PCM is inaccurate on 7.3's.

My dually reads -30 all the time on my scaner but the dash gauge works. No idea why though.

Dz- see if these symptoms are consistent with yours.

http://swampsdiesel.com/files/7.3LInjectorDiagnostic.pdf

Its exactly how my 01 is.

live life full throttle...
load it like a box car, drive it like a stock car

 

[webb06]

Pretty sure the PCM reads engine temp off the oil temp sensor in the 7.3? Correct me if I'm wrong though

 

[lincolnlocker]

Pretty sure the PCM reads engine temp off the oil temp sensor in the 7.3? Correct me if I'm wrong though

There is a sensor for both. Oil temp is on the hpop res and coolant temp is on the water pump housing. Both the same part numbers too.

live life full throttle...
load it like a box car, drive it like a stock car

 

[webb06]

There is a sensor for both. Oil temp is on the hpop res and coolant temp is on the water pump housing. Both the same part numbers too.

live life full throttle...
load it like a box car, drive it like a stock car

Ok. Well I do know whenever running contribution tests and the scanner says the truck has to be at operating temp you can jump the oil temp sensor and check it when cold.

 

[Chvyrkr]

No idea why the PCM has any "readout" for ECT. Everything that adjusts for temps does so based on EOT, AIT, etc... Don't know of a thing the PCM looks at ECT for.

 

[Dzchey21]

Dz- see if these symptoms are consistent with yours.

http://swampsdiesel.com/files/7.3LInjectorDiagnostic.pdf

Thanks for posting this up

After some further trouble shooting I have narrowed it down to cylinder 7 needing an injector, compression checkes out good, buzz test is weak, and I have a dead miss cold on number 7, verified by heat gun on the cylinder, once warm I get the typical 8&3 misfire but the truck runs fine. Swapping a new injector tonight and ill keep everyone posted on what I find

 

[Dzchey21]

Thanks for all the help guys. #7 injector seams to have fixed the truck, starts great and runs smooth instantly. Switching him over to 5-40 for the winter time to ease cranking and start up a bit but other than that pretty impressed overall.

 

[lincolnlocker]

Thanks for all the help guys. #7 injector seams to have fixed the truck, starts great and runs smooth instantly. Switching him over to 5-40 for the winter time to ease cranking and start up a bit but other than that pretty impressed overall.

Have you ever ran synthetic in that truck before?

live life full throttle