Sudden Loss of Power AGAIN - On road with family [St. Louis,MO] (1 Viewer)

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MD
I would appreciate any help and will be cross posting in the clubhouse forum for MO.

I am currently traveling from MD to CO. I had an issue ~8months back [THREAD HERE] it was diagnosed as the MAF which was replaced with an OEM part. I have had no issues up until yesterday. I was on my 2nd day of trip and after driving ~4 hours I pulled off the highway to get gas. I stopped at light and when I went to accelerate I had sudden loss of power, truck would not move and stalled when I fully pressed on accelerator. I did the same routine as previous, disconnected battery & cleaned MAF. It started back up and I made it into parking lot. I HAVE a spare MAF which I installed. Drove another 30min, went to pull into parking lot and same issue (with new MAF). * I did not get a CEL either time but when I checked pending codes I got P0174.

I am deciding if I should try to make it the rest of the way to CO or stay in MO and try to find someone to look at. Any help is greatly appreciated.

Summary of what has happened and what I noticed:

Prior to issue:
- Fluctuating idle around 65mph: I had thought this was a shifting issue b/c of tire size. If i pressed on gas it would downshift and fluctuation went away.
- Had some shaking while on highway. I thought maybe I lost a tire weight. I pulled over and checked, everything looked okay. Got back on highway and it was fine. (Did not turn truck off)

What has got me going again:
- With original MAF (8 months old). Disconnected battery & sprayed MAF. (did not wait 10min) [Drive into parking lot]
- Replaced original MAF with spare. Disconnected battery, waited ~10 min [Drove ~30min]
- Bought another MAF, disconnected battery for 10. [Have driven 45min with no problems]

I just measured all the MAFs.
OEM (8 month old) - 1.9kohms
Advance Auto Replacement (8 month old spare) - 2.0kohms
New Advance auto (new) - 2.0kohms

I have the manual (see below for what I have done). I want to know what I can eliminate based on the fact that when I disconnect battery I am able to get it up and running again?????? Also note its extremely hot outside while I am driving ~95-100f

I have gone through the manual diagnostics and it says to check the following:
air induction system [
injector blockage
MAF [Checked Res okay, cannot measure voltage]
Engine coolant sensor
Fuel Pressure
Gas Leak in exhaust system
Open or Short in O2 sensor
Heated O2 sensor?
Heated O2 sensor heater
EFI or ECD relay
PCV piping
ECM

Thanks in advance for any help
 
are there any cracks in your air intake tube?

It could also be a broken wire that is leading to the MAF (if that is the issue)

what's the code for a P0174

It never is any fun breaking down on roadtrips - don't get frustrated.
 
I don't think there are any cracks but I will check, I have carb fluid so I will spray around for leaks. Will also check resistance on truck side maf wires. I should have also said for PM (prior to trip) I did the following:

p0174 = System to lean (Bank 2)

New PCV valve and all hoses
New air filter
New spark plugs
New fuel filter
New serpentine belt and tensioner
 
Check wiring around the crank. Had an intermittent eventually no start wiring had come loose and crank position sensor wire had worn through. No cel light ever except for a random security code. But the battery had gone down a couple times cranking.

Just a thought of something else to look at.
 
Thanks will check wiring.

I just pulled and checked Engine coolant sensor and I got:

Room temp ~72 = 1.5kohm
Hot water (temp not known) = 0.6kohm

Manual says:
2.32-259 @68
0.31-0.326 @ 176

Question. I have a scanguage and watch it all the time, temps during driving were 195-207 which is normal. Does the OBDII i.e. scanguage read temp from this sensor???
 
The pending P0174 Lean Bank 2 code is probably not related to your MAF. Otherwise you would get a P0171 Lean Bank 1 as well. The plastic intake manifold on the '06 and '07 are more prone to vacuum leaks. So maybe there is a leak on Bank 2 side? But I'm not sure if this would cause all the troubles you are describing here.

A cracked intake tube would throw codes on both banks as well.

Are you able to see how lean bank 2 is running, i.e. what is the total fuel trim for bank 2 (v.s. bank 1)?
 
I am working on setting up the techstream to look at fuel trim.

As for the fuel pump, would resetting via battery disconnect fix it temporarily?
 
It might be the resting, cooling off that’s causing it to work again and not actually disconnecting the battery.
 
I would expect both bk1 & bk 2 lean DTC with bad fuel pump. But it may just show up as bk 2 more than bk 1.

Seems we had a batch of bad fuel pumps in 2006. They'll test find but tend to be weak in low speed mode. Seem when pulling load (higher RPM and higher fuel pump speed) then dropping back to lower RPM, engine dies of fuel starvation (lean condition).

You can try some 44k or Chevron Techron in gas tank with 10 to 20 gallons of gas. This will help with fuel system clogs like fuel injectors. But will not fix bad fuel pump.
 
This symptoms sounds fuel related as well, i know a few 06-07 that have this issue and replacing their fuel pumps solved it. Not saying this is your case but it's worth a shot, pop the seat, get to an oreilly and put in a new pump and see if that'll cure it.
 
I just checked resistance on fuel pump and its 2.3 which is in spec for 72f. It is possible to be good when cold and an issue with hot?

Its sunday so I will have to settle for an advance auto fuel pump but will go ahead and get it
 
In all my experience, issues with fuel pump and other electrical related things get worse with heat.
 
I just checked resistance on fuel pump and its 2.3 which is in spec for 72f. It is possible to be good when cold and an issue with hot?

Its sunday so I will have to settle for an advance auto fuel pump but will go ahead and get it

Be sure to compare your old one with the new. Not unusual for parts houses to give you the wrong one for your year model.
 
If you need someone local to look at it, check out MT Schiele in Crestwood: (314) 849-4700.
 
My experience with problems that are reset with battery unhook are usually sensor related. Computer tells truck something is wrong and truck reacts. Unhooking battery usually resets this until sensor goes off again. I could be cooling off but if it you let it sit the same amount of time without unhooking battery and it doesn't reset then its not just a heating up issue
 
If it was a sensor in this case I would be looking at the coolant temp sensor as a possible culprit
 
I've and 07LX now, having similar symptoms. I've not had time to work on yet. But I do suspect fuel pump. I'll start with OEM fuel cap than fuel pump. It's new to me, so possible the PO doubled squeezed the gas pump handle when filling up. This cause charcoal canister flooding and can make non serviceable. It also can plays roll in fuel system issues.

This bad fuel pump issue of the 06-07, for some reason, does not test as bad. A Toyota Dealerships had driven one hooked up to test equipment and keep checking for over and over for 98K miles. Never found it cause. Finally one day they replaced the fuel pump on a whim, Problem solved.

I'd avoid aftermarket parts if at all possible. May end up chasing your "tail", as they say. Like MAF or fuel pump.

Make sure coolant in radiator is topped. Not just reservoir. But in 06-07 we usually get a DTC not "reaching temp in allotted time" if low. But not always!
 
Sounds like fuel pump to me. If you continue your trip consider filling at every half tank. Could be overheating. Fresh cool gas would help cool down the fuel pump. Replace when you return home or in your spare time during your travels.

I would say start with a cheaper fuel cap solution ;)
 
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