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+--- Thread: isx12 cm2250 fuel pressure only builds if injector harness is disconnected (/showthread.php?tid=6833)
isx12 cm2250 fuel pressure only builds if injector harness is disconnected - num1enloe - 12-05-2020
so ive got a 2010 pete 365 with an isx12 cm2250 that died on the highway.
whent customer called i drove out to take alook and found something ive never ran into before. the injectors are being supplied 5.4v at all times the key is on. which is apparently enough to crack them open. i discovered this by accident when doing the injector leak down test i had removed the harness for easier access to loosen the other end of injector supply line to pivot out of the way and install the cummins cap on the rail. i at first thought i had found the leaky injector. but than noticed i hadnt plugged that harness back in. i had an extra injector harnes laying around so i connected it and found between the two of each injector nuts i had 0.3v than i tested each one for voltage to a frame ground and found the 5.4v. i than tested the harness for shorts and found nothing. so i than tested the ecm directly with engine harness connectors disconnected and found the ecm was sending the 5.4v signal. am i overlooking something or is my ecm faulty?
ecm is fully updated and engine showed no signs of a weakening fuel pump prior to this last load of hay. ive tried reflashing the ecm but still it sends this voltage to injectors.
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - Signature620 - 12-06-2020
Definately try to get hold of a spare ECM
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - num1enloe - 12-07-2020
i had an identical match for part number right next to it last week. i would have had to use a fleet count to swap it to the right code and than another to swap it back i suppose. but would have been worth it in my eyes before ordering a new ecm.
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - Rawze - 12-08-2020
(12-07-2020 )num1enloe Wrote: i had an identical match for part number right next to it last week. i would have had to use a fleet count to swap it to the right code and than another to swap it back i suppose. but would have been worth it in my eyes before ordering a new ecm.
for simply testing it on a leak-down test, the calibration differences from one engine to another would not have mattered much any ways.
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - num1enloe - 12-30-2020
ecm didnt change anything. only time i can get fuel pressure to go above 1000ish is if i unplug injector/jake breake harness from the head. i cant explain it. ive got an extra internal harness laying around. but all wires are ohming out fine. any help would be greatly appreciated!!!
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - Rawze - 12-30-2020
maybe post a screen shot or 2 of any error codes that are coming up. Will it pass an injector leak test...?
<iframe id="lbry-iframe" width="560" height="315" src="https://odysee.com/$/embed/isx-injector-leak-test-for-the-cm2250/e8187fb8d70f0f06388b597cb40751c5536d03dd?r=8p8MjqctPT8PafuYA5mftGueGF8L3how" allowfullscreen></iframe>
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - num1enloe - 12-31-2020
ok ill hook up to it. it holds psi but only with injector harness disconnected. if disconnect at the head crank it over it builds up to where it could fire off but it cant cause the harness disconnected and if i key off quick reconnect harness it fires off but dies instantly as pressure drops. i actually just got done checking over the entire engine harness for shorts and high resistance. everything checks good. im thinking ive got a calibration issue. the crazy thing is this truck was driving dow the road and died and has not fired off since. no sign of pump issues prior or even fuel issues.
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - num1enloe - 12-31-2020
insite doesn t show any faults but i connected with calterm and it shows fault 272
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - Rawze - 12-31-2020
Does the enigne have delete programming in it? ... if so, who did it?
I have seen plenty of bad delete programming that was not worth a damn that caused engine to shut off after so many hours of run time on it because the dips$it who did the programming did not disable all the shutdowns properly and only blocked a bunch of codes. Also, if some moron blocked codes from being able to show up in the dash instead of re-programming things correctly, ... and then later on, a mechanic can't see them, then how is anyone supposed to troubleshoot any issues?.
- I find it highly suspicious that you can only see codes in calterm and not insite or in the dash of the vehicle.
- If you have Calterm then pull a copy of the ecm program out and e-mail it to me ... I will review it and tell you what someone has done... good, bad, and ugly. I PM'd you the e-mail address to send it to.