97 7.3 shuts off and sometimes refires

[slyhog022056]

97 7.3 shutting off while driving, while sitting in traffic etc. I dont understand this i have read every possible thread. my truck will be running fine then it just shuts off at different times, sometimes it will refire if i am moving but if it shuts while at a stop i can usually just turn the key off and restart. when it does shut off the tach drops to 0 and stays until it refires. the last few days i have stopped and shut it off and when i tried to restart there was 0 on the tach while cranking. yesterday i got fuel and went to start it nothing on the tach and no wait to start light tried several times off, wait to start then crank. shut it off got out kicked the tires for the hell out of it and called wife to come get me. while i was on the phone tried again and then it started. tried to drive the 3 miles to the house but it shut off 2 times. but cranked right back up. this morning cranked right up warmed it up and nacked out of drive, as soon as i pit it in 2 nd and let the clutch up it died and wouldnt refire again.
i am thinking ignition contacts on the switch and maybe crank position sensor. i am open to any ideas. this is my only transportation right now. i did check hpop level, new fuel pump 6 months ago, hpop oil dranied and refilled,

 

[IDIoit]

sounds like a IPR to me
do you have a motorcraft CPS?

 

[lotzagoodstuff]

the last few days i have stopped and shut it off and when i tried to restart there was 0 on the tach while cranking.

This is a classic symptom of a bad crank position sensor. Google is your friend, go read more about which one to buy to replace yours.

If a new CPS doesn't solve your problem, you'll need to plug into your OBD plug and try to monitor using Forscan. Again, Google is your friend.

Good luck

 

[slyhog022056]

ipr and ICP were both replaced 2 years ago. this has been doing this for longer than that, just not as often as it is now. and yes both were motorcraft

 

[lotzagoodstuff]

Plug in and see if there are any stored codes.

 

[greenskeeper]

no WTS light would indicate the PCM isn't getting power during the restart.

I'd look at bad grounds, ignition switch, even the fuel bowl heater shorting intermittently but not completely blowing the fuse?

 

[slyhog022056]

went and ordered a forscal tool,
FORScan OBD2 Adapter, VINT-TT55502 ELMconfig ELM327 modified For all Windows
now all the files i have to download for it to run come back as infected malware. and incompatable with windows 10. Totally useless. I am trying to send it back and order a different one,
FORSCAN PRO ELMconfig OBD2 USB Adapter.
Does anyone know if this is a good one? and will it let me make changes for tire diameter?

 

[lotzagoodstuff]

https://www.amazon.com/gp/aw/d/B07JFRFJG6/ref=cm_cr_arp_mb_bdcrb_top?ie=UTF8

This is the wireless adapter I used. I have an older version but it works well on my 1995 with the software it came with as well as Forscan

 

[slyhog022056]

This is a classic symptom of a bad crank position sensor. Google is your friend, go read more about which one to buy to replace yours.

If a new CPS doesn't solve your problem, you'll need to plug into your OBD plug and try to monitor using Forscan. Again, Google is your friend.

Good luck

THANK YOU got the forscan and got it working, got 3 codes, 2 for exhaust back pressure. I think i will have to bypass 1 since it is open 4" exhaust, I reset pcm back to factory and it already runs better, still have to replace the CPS because it still shuts off sometimes, been raining here for a week so i havent been able to get to it. The forscan is great since i can test nearly everything at least it passed nearly every test, i thought i had a fuel injector bad because of the slight miss at idle but they all checked out good all the way from idle to 2750 rpm. the miss went away after resetting pcm

 

[79jasper]

What are you going to "bypass?"

Sent from my SM-G988U using Tapatalk

 

[slyhog022056]

i think its the exhaust back pressure switch. since no mufflers there isnt much back pressure

 

[greenskeeper]

i think its the exhaust back pressure switch. since no mufflers there isnt much back pressure

Do you still have the EBPV intact?

If so your best bet is to gut the valve and plug the actuator. Leave the EBPV connected electrically but open to atmosphere.

What codes are you seeing for the EBPV ?

 

[slyhog022056]

if i could find where they got saved at...
P1111
P0472
P0113
P0475
guess it just 2 for the exh backpressure
0113 is iat sensor

 

[greenskeeper]

if i could find where they got saved at...
P1111
P0472
P0113
P0475
guess it just 2 for the exh backpressure
0113 is iat sensor

None of those codes would cause the truck to shut off IMO

 

[slyhog022056]

i know, i think thats the cps those are what showed up from forscan. will be trying to get to most of it this weekend now that we have sunshine.
When i had the forscan hooked up i ran it around and all over the place trying to get it to cut off but it didnt