Intake grid heater coming on while driving

[Bob4x4]

What should the labor cost be on the replacement?

Warranty pays next to nothing so an hour is what you will probably end up with. It can be a DIY job if you have a GOOD torx bit and some dexterity

 

[Bill Weber]

I would double check the intake air temp sensor. Mine was cheap to replace and cured the problem. If on the road and the heater grids come on - disconnect the wires at the grid or better at the solenoids. Don't need the air heater (for starting) till the temp gets into the teens or lower.
Bill

 

[cerberusiam]

I would double check the intake air temp sensor. Mine was cheap to replace and cured the problem. If on the road and the heater grids come on - disconnect the wires at the grid or better at the solenoids.

The grid heater relays are de-energized once speed reaches 15 mph. They won't stay on once your driving unless the relays stick and you will find that when the battery boils dry or wires melt off.

The grid heater icon on the dash is controlled by the ECU and has no refernce to actually powering the grids. The icon coming on while driving and getting the dings is a diagnostic feature in the ECU indicating rail fuel pressure problems, thats what the OP is talking about.

 

[Prairie Dog]

The grid heater relays are de-energized once speed reaches 15 mph. They won't stay on once your driving unless the relays stick and you will find that when the battery boils dry or wires melt off.

The grid heater icon on the dash is controlled by the ECU and has no refernce to actually powering the grids. The icon coming on while driving and getting the dings is a diagnostic feature in the ECU indicating rail fuel pressure problems, thats what the OP is talking about.

That's what I eluded to earlier but the point was quickly lost as will yours. LOL!

 

[cerberusiam]

So I have 6 new injectors ordered from my local injector/fuel pump shop ($280 ea. for Bosch factory remans. )

At that price, I would suspect a reman Bosch injector NOT a Bosch reman injector. I think the price is too low for a quality producy and suspect there are still injector problems.

 

[moto_god]

Did you ever get the problem with your truck fixed? With the dtc's you said it was setting indicates you most likely have more than two injector's returning too much fuel, if it was only a "glitch with the software" you would not have any dtc's and would not have a derate/ loss of power.

 

[Bill Weber]

The grid heater relays are de-energized once speed reaches 15 mph. They won't stay on once your driving unless the relays stick and you will find that when the battery boils dry or wires melt off.



The grid heater icon on the dash is controlled by the ECU and has no refernce to actually powering the grids. The icon coming on while driving and getting the dings is a diagnostic feature in the ECU indicating rail fuel pressure problems, thats what the OP is talking about.

If the temp sensor is bad the grids will stay on till the batteries go dead. Will not melt wires (at least in 40 miles). No icon on dash. What I noticed was the voltmeter drop to (-). And lights dim, if on. The relays were notsticking. Dealer couldn't find problem. Can't remember why but finally pulled intake temp sensor, put tip in boiling H2O and it was still telling the relays to engage. $10 and new sensor and all has been well for 7+ years.

 

[AH64ID]

The grids also have a 2 min and/or 18 mph timer, a faulty IAT sensor is overruled by either of those even when the intake temp is sub zero.

 

[Bill Weber]

AH64ID; sorry I failed to mention that the truck I had my problem with was a 97. They have probably changed things in the newer trucks. In my 97 nothing o'ruled the IATS.

 

[AH64ID]

That makes more sense.

 

[nmmegacab]

Hello new to being a diesel owner and am having similar issues. My truck is an 07 2500 megacab 4x4 with the 5.9 and a 6 speed manual transmission. It has 5 inch straight exhaust and I have a super chips flash pack on it with a quadzilla boost cooler stacked and cold air kit. When I'm hard on the throttle and lift a P1222 code pops. Had the truck looked at by a Cummins Rocky Mountain Tech and found no issues. Before the code only popped when I towed. But now I can recreate it at will. I had read and thourobred diesel said that there is a glitch in the newest program from Chrysler. But from what I read here is that's a fallacy.
Any help would be greatly appreciated.
Thanks

 

[cerberusiam]

The 1222 code is usually the first to set when therre are injector issues developing. It is set when the fuel return exceeds a predetermined amount and the engine is motoring.

What does "looked at" entail? There are very specific tests for injector contribution and return rates installed in the vehicle. Were those test run?

 

[nmmegacab]

He put a scanner on it and ran several diagnostic tests and said he saw nothing wrong. Said it was running great. But today and yesterday it started hard and has never been before. We did have very cold temps though. I need to get this figured out as I can't tow my race car or 5th wheel because it derates it so bad. Thanks for the info

 

[Prairie Dog]

Your injectors have had it. The light coming on and the hard start are both further proof of this.
Find another mechanic who knows how to do an injector return rate test. If it's high then you can try a retorque of the cross over tubes but more than likely it's time for a new set of injectors.

 

[nmmegacab]

That's what I was afraid of. It does have 166k on it. Is it a difficult job to change them out?

 

[cerberusiam]

Pull the SuperChips off and see if that makes any difference. Sometimes these power adders cause more issues than they fix.

If it is starting hard and you are getting the leakage DTC's time to start some diagnostics. It is possible that a failing lift pump and\or a sticking FCA, and\or a popped rail pressure relief valve can cause a false positive on leakage. Bsically start at the tank and verify the delierfy pressures and componenets are in good shape. In the end it is almost always injectors but you really have to do the diagnostics.

 

[nmmegacab]

Injector recommendations?

 

[cerberusiam]

New Bosch injectors, only thing you really want to do. Then the question becomes stock tips, larger stock tips, or switch to SAC nozzles.

TC diesel, Diesel Auto Power, Engineered Diesel, etc, can all get you what you decide on.

 

[nmmegacab]

I'm not familiar with all the options... Sac nozzles? Larger stock tips? Sorry for my ignorance.

 

[cerberusiam]

I'm not familiar with all the options... Sac nozzles? Larger stock tips?

....and the big can of worms is opened. :-laf Don't be sorry, it is not bad thing to be ignorant of.

First off the bodies on all the 5.9 CR engines are the same. Later production runs have a differnet metallurgical composition frequently called stainless steel. It is not really but the bodies are tougher and better able to handle the high pressures over time. Rail pressures on a stock engine can routinely see 30k psi spikes, if a pressure modification box or program is used that can go to 40k. If you get new bodies then all that needs considered are the nozzles.

VCO nozzles - The pintle seat in the nozzle contains the orifices. The pintle seats on the orifices so there is no chance of dribbling fuel, its an emissions thing.

SAC nozzles - The pintle seats in the nozzle above the orfices. This leaves a very small chamber under the seat that directs the fuel to the orifces. The SAC nozzles by design have more metal in the tip area that is in the cylinder. Les sprone to cracking tips from high EGT's.

Deep spray bowl - 04.5-07 bowls are deeper and flatter in the center. The fuel stream is designed to be injected into the deepest part of the bowl then spread. Default spray pattern is 124 degrees.

Re-entrant bowl - 03-04 bowls are shallower and flatter with a lip around the outside to redirect the fuel stream back over the bowl. Default spray pattern is 143 degrees.


Stock +04.5 nozzles - 5 holes, 124 degree pattern, VCO nozzles, stock orfice size

60 Hp +04.5 Nozzles - 5 holes, 124 degree pattern, VCO nozzles, larger than stock orifice size

BMS 50 HP SAC 143 nozzles - 7 holes, 143 degree pattern, SAC nozzle

BMS 50 HP SAC 126 nozzles - 7 holes, 126 degree pattern, SAC nozzle

(90 and 100 HP nozzles are also available but they are just larger orfices in the same configuration)


The +04.5 can use the 124, 126, or 143 degree nozzles. The tuning has driving has to differ a bit. The 124 and 126 50-60 HP nozzles just need a closer eye on the EGT's. The 143 degree nozzles need timing chnages and some rpm limits.

In my experience the 7 hole SAC nozzles provide a better pattern and atomization of the fuel. The larger 50 HP SAC injector can actually improve mpg in some cases. The 60 HP VCO is either a zero gain or loss in mpg, lots of power but they just don't seem to be as effective in the efficiency department.