| Author |
 Topic  |
|
|
Fastback
Top Member
1500 Posts |
 Posted - 12/16/2015 : 08:57:10 AM
|
| Maxxforce 7 engine has some occasional "hiccups", no check engine light, no water in fuel/water separator. Does have an inactive code described as "VGT commanded position below a threshold". Any thoughts? |
|
|
JoeHEB1
Advanced Member
498 Posts |
Posted - 12/16/2015 : 09:08:07 AM
|
| Had one that was trying to cut out while accelerating, it was intermittent. It didn't give an engine light or the VGT code. It ended up being the FRP (fuel rail pressure) sensor. Not sure if you are having the same symptoms though. |
 |
|
|
Fldawg
Active Member
15 Posts |
Posted - 12/17/2015 : 07:15:25 AM
|
| do a bounce test on the turbo see if it is free, if not take it apart and clean the vanes they usually will stick and cause a code. they tend to do it if it sits a long time like Christmas hoilday |
|
|
|
Fastback
Top Member
1500 Posts |
Posted - 12/17/2015 : 11:27:20 AM
|
| Turbo linkage moves freely with my finger with key off, with engine off key on I can't move it. I assume this is normal. |
Why yes, the ORIGinal CHARGER is a Fastback |
|
|
|
Ryan5r
Senior Member
USA
55 Posts |
Posted - 12/17/2015 : 11:42:50 AM
|
| I had one a few weeks ago doing the same thing and it was the ICP |
|
|
|
Fastback
Top Member
1500 Posts |
Posted - 12/18/2015 : 12:24:52 PM
|
I do believe its fuel pressure related, I had bus hooked up to my ServiceMaxx and when it "hiccuped" I noticed a large variation in fuel rail pressure.
The way this bus runs, if it had spark plugs and a distributor, I would be checking the cap and rotor. |
Why yes, the ORIGinal CHARGER is a Fastback |
|
|
|
mysterytrain
Active Member
34 Posts |
Posted - 12/19/2015 : 3:56:32 PM
|
| Would also guess fuel pressure, I never believe fuel pressure data on the screen, I use an OTC fuel pressure tool, not sure of the pressure req. for mxf7 but the dt466 is 65 psi, if you see a bounce between like 40 and 70 ( press sensor is too slow to see this) it will run rough bad starts, "hickup" for lack of a better term, should be rock solid at 2,000 rpm even a bounce at idle will cause problems and then it is just a fuel pressure kit. |
|
|
|
Fastback
Top Member
1500 Posts |
Posted - 12/21/2015 : 04:29:58 AM
|
| The MaxxForce 7 is high pressure common rail, fuel rail pressures I saw from low to high idle, ranged anywhere from 5,000 psi to 15,000 psi. |
Why yes, the ORIGinal CHARGER is a Fastback |
|
|
|
Fastback
Top Member
1500 Posts |
Posted - 01/04/2016 : 09:51:47 AM
|
UPDATE;
Bus went to the dealer, tech believes the problem is being caused by the crankcase venting back into the engine air intake and effecting turbo operation. Going to install "up"date kit, basically back to a road draft tube I believe.
So maybe the fuel pressure variations are the result of the engine hiccups and not the cause. Time will tell. |
Why yes, the ORIGinal CHARGER is a Fastback |
|
|
|
JoeHEB1
Advanced Member
498 Posts |
Posted - 01/11/2016 : 08:53:22 AM
|
| Curious as to how the dealer repair went? Did it fix the problem? |
|
|
|
Fastback
Top Member
1500 Posts |
Posted - 01/11/2016 : 09:05:44 AM
|
Well I picked it up friday and it does now have a road draft tube. Driver used it on his friday afternoon route and said the "hiccups" are gone but when he was pulling a long hill he lost power and now has the puff of smoke with an exclamation point light on.
Not sure if its related to something dealer did, I nursed it back to my location but have yet to run it in my shop.  |
Why yes, the ORIGinal CHARGER is a Fastback |
|
|
|
aaronwilmoth80911
Top Member
538 Posts |
Posted - 01/11/2016 : 11:40:51 AM
|
| DPF may need to be baked. |
|
|
|
JoeHEB1
Advanced Member
498 Posts |
Posted - 01/11/2016 : 2:03:12 PM
|
| What a nightmare these V8's... |
|
|
|
Fastback
Top Member
1500 Posts |
Posted - 01/12/2016 : 07:37:17 AM
|
| Bus in my shop, hooked to servicemaxx, active code is 1729-3251 "EGDP signal out of range low" |
Why yes, the ORIGinal CHARGER is a Fastback |
|
|
|
aaronwilmoth80911
Top Member
538 Posts |
Posted - 01/12/2016 : 09:46:52 AM
|
| On the Maxxforce DT, this would require the differential pressure tubes be pulled off the DPF and checked for blockage. If they are, the DPF might need to be baked. |
|
|
|
mysterytrain
Active Member
34 Posts |
Posted - 01/12/2016 : 8:14:56 PM
|
| the egdp sensor is done for, when replacing don't put it in backwards won't read right. |
|
|
|
Fastback
Top Member
1500 Posts |
Posted - 01/13/2016 : 07:56:36 AM
|
quote:
Originally posted by mysterytrain
the egdp sensor is done for, when replacing don't put it in backwards won't read right.
Not that it means much but sensor was replaced last August, dealer has the bus now again, we will see what they come up with this time. |
Why yes, the ORIGinal CHARGER is a Fastback |
|
|
|
Fastback
Top Member
1500 Posts |
Posted - 01/27/2016 : 08:23:06 AM
|
| Well they replaced the EGDP sensor again and so far so good. |
Why yes, the ORIGinal CHARGER is a Fastback |
|
|
|
slippert
Top Member
USA
630 Posts |
Posted - 01/27/2016 : 09:37:05 AM
|
Is that sensor part #3626432C1? did they install or was the #2612020C1 tin sheild installed with it?
I have to replace a fair amount of those sensor here too, if it makes you feel any better... no rime or reason sometimes why they go bad... But they do seem to hold up longer, when tin shield is in place.. doesn't seem to happen as often now that I put those sheilds on them....
Now that I said that, I will probably be replacing one tomorrow morning!! |
|
|
|
Fastback
Top Member
1500 Posts |
Posted - 01/27/2016 : 09:42:39 AM
|
| The invoice reads # 3626432C1, no mention of shield part number. |
Why yes, the ORIGinal CHARGER is a Fastback |
Edited by - Fastback on 01/27/2016 09:44:28 AM |
|
|
| |
Topic |
|
2007 Emission MaxxForce 7 "hiccups"
