| Author |
 Topic  |
|
|
RonF
Top Member
867 Posts |
 Posted - 04/03/2017 : 11:27:40 AM
|
Pulling my hair out. This bus had injector cups put in by the dealer back in November and ever since it has had an intermittent issue where it will crank but not start. Of course the dealer cannot duplicate this issue.
Last week I connected a manual gauge to where the oil pressure sending unit goes and determined that it wasn't build low oil pressure. We dropped the pan and checked the pickup tube, no issues, removed the pressure regulators and didn't see any issues. The bus ran Friday afternoon. Wouldn't start Sunday, wouldn't start this morning. We pulled the hose off the turbo and had oil, bus still wouldn't start. Had it towed to the shop and as soon as it was off the wrecker, it started.
No engine codes according to the dealer. Any help? What am I missing. |
|
|
JoeHEB1
Advanced Member
498 Posts |
Posted - 04/03/2017 : 2:49:46 PM
|
| Check the wires on the IPR connector, assuming it's a DT. You mean not even ICP unable to build code came up? Again assuming it's a DT. I have one giving me holy right now but I won't hijack your thread. I'll start my own if I can't get it started here soon. I've been trying for 2 weeks now. |
 |
|
|
RonF
Top Member
867 Posts |
Posted - 04/04/2017 : 04:20:47 AM
|
| Let me correct this. It's a 3126 C-7 |
US Army retired CMBT |
|
|
|
Thomasbus24
Administrator
USA
4544 Posts |
Posted - 04/04/2017 : 04:33:00 AM
|
| Do you have a twin bus you can swap ECMs with? Had an ECM go bad and cause random no-starts a few years ago. Drove us nuts, then one day it wouldn't start anymore and showed faults for all 6 injectors, no faults would show up prior to the total failure. |
|
|
|
RonF
Top Member
867 Posts |
Posted - 04/04/2017 : 05:29:02 AM
|
| I do have a twin, however I just found the bottom engine speed sensor wire if frayed and possible touching each other. I'll repair that and see what happens. |
US Army retired CMBT |
|
|
|
Thomasbus24
Administrator
USA
4544 Posts |
Posted - 04/04/2017 : 05:57:29 AM
|
| Yeah that isn't doing you any favors like that! |
|
|
|
sambrutay
Advanced Member
United States
271 Posts |
Posted - 04/04/2017 : 06:01:58 AM
|
| only do it when hot? I would suspect cut o-ring on injector. Frayed / touching wires for speed sensor can surely give you some problems also..... (update, guess I should have read first post more clearly. looks like it is not a hot start problem.) |
Bruce |
Edited by - sambrutay on 04/04/2017 06:04:13 AM |
|
|
|
JoeHEB1
Advanced Member
498 Posts |
Posted - 04/04/2017 : 06:22:28 AM
|
quote:
Originally posted by RonF
Let me correct this. It's a 3126 C-7
My bad, I thought 3126 was the code. |
|
|
|
dferrell
Senior Member
102 Posts |
Posted - 04/05/2017 : 3:39:13 PM
|
| I have had bad cam sensors do this. |
|
|
|
td83
Senior Member
83 Posts |
Posted - 04/06/2017 : 10:56:01 AM
|
| Im with dferrell sounds a lot like cam sensors to me and sometimes you wont get a code replaced a number of these in our 3126's |
|
|
|
ReliantDiv419
New Member
3 Posts |
Posted - 04/06/2017 : 3:49:23 PM
|
Team, I had 181 of the Thomas buses with the 3126 Cats. We started doing the injector cups ourselves and noticed a few that the drain plug on top of the head comes loose. Normal result is a no start condition. The dealer may have loosened it up to relieve oil pressure to keep the oil out of the head/injector cups during install. It may have backed out.
Check for a pipe style plug on the top of the head and also verify all injector harness are tight.
Hope you sort it out. |
|
|
| |
Topic |
|
3126 no start issue, sometimes
