Intermittent Power Problem

[mrtibbs]

Hi all. I hope that someone can help me with this issue. Occasionally when starting off in the morning or after the car has been left stationary for a period, the engine falters and feels as if it is about to stall. It then picks up and off we go. I am concerned that it will stall one day or have a power loss when I pull out of a junction or a roundabout.

Has anyone had this problem and if so what did you do to cure it please?

I am thinking that there may be air getting into the fuel line or something like that?

TIA

 

Keith

[gordy]

I was going to say If it starts ok its not air in fuel, whether Petrol or Diesel. So does it start ok from cold. Looking too MAP for this Faltering and slow to take off. 

Edited November 11, 2018 by gordy

[mrtibbs]

Thanks for your reply. I should have mentioned that it is the 2.8l diesel engine.

The engine starts reasonably, not always great but after a few cranks it usually fires up. Sometimes the battery isn't up to it (I think something is draining the battery) but that is a separate issue altogether.

Thanks again

 

Keith

[gordy]

Yes need to get that battery seen to and possible peracetic drain first. Some experts on here regarding upping the alternator output and drain to Audio.

[QinteQ]

MEGGA POST

 

Battery & Drain / Loss

 

From - 25 May 2017 - 09:26 PM

Battery: Choice,

 

Battery choice, like choosing a wife, provokes different opinions on what is beautiful. The issue however are simple. You should be looking for about 800CCA over 80aH, this is a physical size that will not fit the CRD battery tray, so get a big one and modify the tray, or get a smaller one and take your UK winter chances. There is a~n~other UK issue of lifestyle, its a use it or lose it condition. If like me you do 2000 miles per annum with two 15 minutes trips once a week you will regardless of battery size / cost never keep that battery charged, the BUS [over 7 or so days] at resting will use more than the 30 minutes the alternator was able to replace.

 

Different people have success with different batteries, I'm sure the UK users will come to your aid with their suggestions, particularly the Scottish contingent who have an even colder climate than I. For myself I originally had an underpowered Banner Uni Bull 690 over 70 and my replacement now is a much preferred Varta 585 400 080 @ 85aH / 800CCA my backup permanently on a 9 stage charger is a  Bosch S5 Type 96 at 800 over 80. Never use one of those 'put your reg in here' dBase's they are rubbish [wiped the dribble from his nose] and will offer you a petrol spec / size battery not CRD capable. If you cant face modding the battery tray go for a RED TOP spiral of 800 CCA. See here for orientation. NOTE : I have a poor 'lifestyle' use.

 

Power seat fuse : are as stated droppers, as you have had your battery removed for 4 days the 'droppers' should re-set themselves via the BCM/IPM

 

Lifestyle : Two 15 minutes trips once a week.

 

The  higher  the  voltage  applied,  the  faster the battery will charge, charging at too  high a voltage WILL  damage  your  battery. A simple 100Ah open lead acid  battery and a 180A charger connected to the battery discharged to 50% :

 

- @ 50% full @ 13.2V current was 35A

- @ 50% full @ 14,8V current was 160A [improvement of 457%]

- @ 75% full @ 13.2V current was 1A

- @ 75% full @ 14.8V current was 60A [improvement of 6000%]

 

Its not linear so :

 

- two 15 minute periods @ 13.2V is 2 x 15 minute @ 21Ah, compared to ;

- two 15 minute periods @ 14.4V is 2 x 15 minute @ 60Ah, is an improvement  of  about  300%

 

The temperature sensor under the battery will drop [ temperature compensator's on modern alternators will compensate] the voltage output from about 14.0V to about 13.2V. The problem I have with this is the engine compartment soon reaches temp and the battery assumes its fully charged.

 

- 13.20 volts is about what you would expect from [split diode - does not apply to Voyagers, and] this vehicle with a temp sensor & alternator compensator

- 14.00 volts  is about what you would expect from any typical alternator without a vehicle temp sensor & alternator compensator

- 14.40 volts is what you would expect from a sealed lead acid to prevent [they tend to gas @ 50ºC] excessive gassing

- 14.80 volts is what you can risk pushing it to with an open lead acid to prevent damage to other equipment connected to the battery at the same time

 

NOTE01 : There are IOD 7 functions that are always 'live' when you think your car and battery are both asleep, they pull a combined 0.025 ampere draw.

 

• Electrical items left on.

• Faulty or improperly adjusted switches.

• Faulty or shorted electronic modules and components.

• An internally shorted generator.

• Intermittent shorts in the wiring

Remote key fob

Radio

Heater blower

Folding mirrors

Central locks

Interior lights when the key is in the ignition

 

 

IGNITION-OFF DRAW TEST - reproduced from the Actual Chrysler issue to main dealers workshop manual.

 

Allow twenty minutes for the IOD to stabilize and observe the multi-meter reading. The low-amper- age IOD should not exceed twenty-five milliamperes (0.025 ampere). If the current draw exceeds twenty-five milliamperes, isolate each circuit using the fuse and circuit breaker remove-and-replace process in Step 4. The multi-meter reading will drop to within the acceptable limit when the source of the excessive current draw is disconnected. Repair this circuit as required; whether a wiring short, incorrect switch adjustment, or a component failure is at fault

The term Ignition-Off Draw (IOD) identifies a normal condition where power is being drained from the battery with the ignition switch in the Off position. A normal vehicle electrical system will draw from fifteen to twenty five milliamperes (0.015 to 0.025 ampere) with the ignition switch in the Off position, and all non-ignition controlled circuits in proper working order. Up to twenty-five milliamperes are needed to enable the memory functions for the Powertrain Control Module (PCM), digital clock, electronically tuned radio, and other modules which may vary with the vehicle equipment. A vehicle that has not been operated for approximately twenty one days, may discharge the battery to an inadequate level. When a vehicle will not be used for twenty one days or more (stored), remove the IOD fuse from the Integrated Power Module (IPM). This will reduce battery discharging.

 

BatteryMOD

 

I like many of us was an early adopter of AGM, most of us by now will be AGM. It occurs to me that the safe μF we chose for the buttonMOD could be changed to give closer to 14.4V than the 14.1 I was getting. I went 13.9 to 14.1 it would be nice to have that extra .3V, it would make a hell of a difference on a big 80aH even over such a short charging time frame as 15 minutes.

 

I was thinking 22K Ω @ 1/2 watt would be a goodish guesstimate for keeping it under the 14.6[ish] although I'm sure it would be safe a little higher so I upped it to 22K Ω @ 1/2 watt, now tested over two summers and winters and .... smack on 14.4-6 winter and 13.9+ summer steady across the REV range. This will better recover the winter loss more quickly. Of course in the summer the ALT output will be / and is limited by the lower battery replenishment needs. So the 14.5-6V over the winter and its now an average of 13.9- 14+V summer and no longer a "guesstimate" but a fact. Well pleased !

 

NOTES: see here for lots of bits on parasitic / battery power loss.

Edited November 13, 2018 by QinteQ