P38A Duchess is in the garage!

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Timing modulation is high. I'd be checking the static timing using a dial guage as per RAVE in the first instance.

The fuel filter should fill up pretty quickly. Is there anything that might restrict flow anywhere? Clip done up too tight?

Does the pressure reading change as you rev it and the turbo spools up? Is the MAP pipe connected between the underside of the inlet manifold and the fuel filter housing?
 
Flossie said:
Can someone click on that link and tell me if it works please?
Click to expand...
Yes the link works.
What was the engine temperature? If the engine temperature was anywhere near normal running temperature of 90/95C, then the modulation is way out, should be around 50%. Well stretched chains by the look of it. Can still be adjusted to bring the timing into spec.
I posted charts of modulation relative to engine temperature a few month ago, I can re-post them if you wish.
You should always manually fill the fuel filter when fitting a new one.
 
I don't know the Nanocom as I have a Faultmate, but if it says "invalid fault" I would have thought that the reading is invalid?
I get the "fuel flow out of range" on my project car, it has no discernible effect on operation, I keep looking into possible reasons but no success so far.
 
Grrrrrr said:
Timing modulation is high. I'd be checking the static timing using a dial guage as per RAVE in the first instance.
Bugger, haven't got a dial gauge.

The fuel filter should fill up pretty quickly. Is there anything that might restrict flow anywhere? Clip done up too tight? All pipes are original pushfit, no hose clips or owt.

Does the pressure reading change as you rev it and the turbo spools up? Is the MAP pipe connected between the underside of the inlet manifold and the fuel filter housing?
Click to expand...
Don't know about the pressure, I'll do some better vids tomorrow now I know how to do it.
Yes, map pipe new and connected, even made sure the inlet on the manifold was clear.
Edit- messed the quoting up but if you expand your quote my replies are there.
 
Last edited:
Datatek said:
Yes the link works.
What was the engine temperature? If the engine temperature was anywhere near normal running temperature of 90/95C, then the modulation is way out, should be around 50%. Well stretched chains by the look of it. Can still be adjusted to bring the timing into spec.
I posted charts of modulation relative to engine temperature a few month ago, I can re-post them if you wish.
You should always manually fill the fuel filter when fitting a new one.
Click to expand...
Temp was 87 Deg.
Yes please for the figures.
I'll do some more vids tomorrow.
I normally always do fill the filters but I went to the garage, got 20ltrs and put it all in the tank and forgot to save a bit. Queued for yonks to get that as well!
I bridged the relay to fill the filter and clear line plus a bit longer for good luck then fired her up, no other bleeding carried out. Starts well from cold.
 
Flossie said:
Temp was 87 Deg.
Yes please for the figures.
I'll do some more vids tomorrow.
I normally always do fill the filters but I went to the garage, got 20ltrs and put it all in the tank and forgot to save a bit. Queued for yonks to get that as well!
I bridged the relay to fill the filter and clear line plus a bit longer for good luck then fired her up, no other bleeding carried out. Starts well from cold.
Click to expand...
Figures tomorrow. What's it like to start when hot? Is there a hot start mod fitted?
 
No hot start mod unless it can be hidden, all looks standard to me.
Starts well hot, little longer than cold which is pretty instant.
 
P38 Modulation checks with diagnostics.

Following on from my post asking about the variation of modulation with coolant temperature and my post about the effect of modulation on hot starting, this post highlights the variation of modulation with coolant temperature on 2 cars.

Way back I established that running temperature with the viscous fan and cowl in place was between 90 and 95C, I did this to establish the temperature at which to set the stat for the electric fans mod. My tests cover from cold to 95C on one car and to 100C on the other and correlates the variation to the position of the temperature gauge needle. I can find no correlation in variation to fuel temperature (there is a fuel heater in the filter head) which always ends up around 43C. There is no significant cooling of the FIP from the viscous fan for two reason, firstly the FIP is out of any airflow as it's well hidden behined the cam chain case, secondly blowing air at 90C+ over an object that is at 43C is going to raise the temperature not lower it. The tests were done with the bonnet open avoiding heat build up under the bonnet. Thus the absence of the viscous fan & cowl and the electric fans are not relevant to the fuel temperature.

The gauge on both cars is one minute to 12 from just over 85C to 100C Probably to 105C as Roman rob states, as can be seen from the tables, the modulation varies considerably between 85 and 95C. Thus for us amateurs, checking modulation with diagnostics and using the dash gauge to judge “up to temperature” can be very misleading and IMO modulation should be checked at a minimum of 90C as shown by diagnostics. I take 95C as the temperature for checking.

The two cars have the same EDC hardware issue, but the software and firmware revisions are different. The trajectory of the modulation against temperature of 1999 car is, to me, very strange, why it 's like that I have no idea. The late 2000 looks more normal although at 136K miles, the static could do with re-setting but as it starts well hot or cold it will not get done anytime soon. Both cars run well and give much the same fuel consumption

upload_2021-11-5_12-18-56.png

upload_2021-11-5_12-20-15.png
 
I've updated on my other thread but for continuance I do it here too.
Modulation was indeed way to high @ 85% iirc, using ,,@Datatek method I've got it down to 50% ,+/- 5 and she sounds lovely, no coughing or stalling when engaging D or R although she's not been on a run yet just backwards and forwards on my short driveway. The run to the MOT will be nerve wracking.
Will the gearbox work?
Will the transmission be quiet?
Will the brakes pull up true?
Will the abs light go out?
Will it break down?
Will it fail on emissions?
I hate MOT time...
 
She’ll be fine:) you’ll be a bag of nerves with no nails left:D.
Relax take a breath, read back through your Fred, then tell me if somebody else did all this you would be worried about an MOT;).
Take the long way to the testing station and give it a heavy foot:).

J
 
I think I might get a bottle of that fuel cleaning stuff to chuck in the tank although she doesn't smoke at all but when I was running it yesterday when the modulation was high and when I got it down to 57-63 I could smell diesel smells quite pungent really, didn't check that today now modulation is perfect. Forgot..:rolleyes:
Going to play some more tomorrow, bonnet open has popped up on the dash which is new and the bonnet is shut.
Will book MOT tomorrow probably and it may be weeks away anyway as there is a back log I've heard.
 
Flossie said:
I think I might get a bottle of that fuel cleaning stuff to chuck in the tank although she doesn't smoke at all but when I was running it yesterday when the modulation was high and when I got it down to 57-63 I could smell diesel smells quite pungent really, didn't check that today now modulation is perfect. Forgot..:rolleyes:
Going to play some more tomorrow, bonnet open has popped up on the dash which is new and the bonnet is shut.
Will book MOT tomorrow probably and it may be weeks away anyway as there is a back log I've heard.
Click to expand...
Bacterial growth in diesel if the car is not used a lot is not unusual, happens all the time on sailing boats. You can buy treatment stuff on line or at a marina. Always best to keep the tank full as the main cause of problems is condensation in the tank in winter, with a full tank there is less surface area for condensation to occur.
 
Datatek said:
Bacterial growth in diesel if the car is not used a lot is not unusual, happens all the time on sailing boats. You can buy treatment stuff on line or at a marina. Always best to keep the tank full as the main cause of problems is condensation in the tank in winter, with a full tank there is less surface area for condensation to occur.
Click to expand...
Tank was removed and drained/cleaned, new filter and fresh diesel. Thinking the injectors might be a bit gummy as she was stood 4 yrs.
The 15 LTRs I drained from the tank was mixed 50/50 with my bio and run through my 110 TDI, she loved it!
 
Flossie said:
Tank was removed and drained/cleaned, new filter and fresh diesel. Thinking the injectors might be a bit gummy as she was stood 4 yrs.
The 15 LTRs I drained from the tank was mixed 50/50 with my bio and run through my 110 TDI, she loved it!
Click to expand...
If you do have diesel bug, you just put it in the 110 tank as well, and gave it some fresh nutrient, and a good stir! :D

Get some biocide in there.
 
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