Weird and VERY odd engine prob tonight - Ideas ?

[Hybrid_From_Hell]

Drove the 90 home tonightr

Its was EXCEPTIONALLY cold outside, ice everywhere, and the engine seemed "Unresponsive"

Drove home 2-3500 RPM, seemed very unkeen to "Go" until "Booted"

Got home, got out, engine running smoothly, but a smell that was unusual

Lifted bonnet, Big Bore Cast 4 > 2 Manifolds glowing red WTF ?

The only thing I can think of is the exceptionally cold air runing through the snorkel, which

maybe could have caused a further chilling, but other than that stumped. ????

I'll disconnect the snorkel at Air Box tommorrow, but anyone know WTF is going on here ????????

Puzzled of Fernhurst

Nige

[SteveRK]

Exceptionally cold air = exceptionally dense air per cubic volume being sucked in?

If for whatever reason the ECU isn't able to determine density of the air (as a calculation of its temperature) then it might be running weak, hence glowing manifolds?

[fozsug]

Frozen air filter?

[zoltan]

Not icing up in the snorkel?

[Phil Hancock]

Possible timing out problem, retarded.

[elbekko]

IAT sensor that can't handle low temperatures and is messing up the fuelling perhaps?

[Diff]

I agree with Phil. Sounds like Timing badly retarded - or advance not operating. This would account for the inability to rev under load and the exhaust manifold temps.

Why the megasquirt isn't advancing the timing is another question. Possible crank sensor problem? - Not reading engine speed?

Good Luck Nige, Regards, Diff.

[Jon White]

Engine running too rich causing the excess fuel to detonate in the manifolds.

Probably due to low temperatures or incorrect ECU settings causing the engine to constantly be running with warm up enrichment (basically equivalent of running with the choke out all the time).

Jon

[TheRecklessEngineer]

Cold air is more dense. Therefore it's harder for the Landy to move through it = engine working harder.

[Hybrid_From_Hell]

Possible timing out problem, retarded.

Nope

MLV shows timing as normal

[Hybrid_From_Hell]

Engine Temp showing on MLV as 82-88 degrees

IAT showing corect temps

Will see with snorkel disconnected what that does

Nige

[Bull Bar Cowboy]

Unresponsive and red hot manifolds are a classic case of retarded timing ………. Usually many degrees ATDC

Although MLV shows that the correct timing signal is being sent to the EDIS module, you don’t actually know that EDIS is doing its stuff.

Get the timing light out next time it happens.

Alternatively it could be a very, very lean mixture, but this is more unlikely ……….as cold air will call for a richer AFR from the ECU......... Check for white plugs.

[V8 Freak]

Throttle potentiometer registering ok ?

Vacuum tube connected ok ? (I'm guessing so cuz it's ticking over..)

Air temp registering ok ?

Has sensor moved in the bracket and changed where the timing is being read from ? MLV will report the angle it's working to, not where the sensor is compared to TDC....

Hand over the manifolds and I'll see if they glow on my lowly engine..

Neil

[landmannnn]

One of the throttles sticking? (is it 2 or 3 on that engine?)

[zoltan]

Will see with snorkel disconnected what that does

Nige

Could be hibernating birds or mice

Oh, how many guesses have we got left?

[zim]

It's heard that you're getting rid of it for a bigger one, so it's sulking

[Mo Murphy]

Tdi missing ?

Mo

[Hybrid_From_Hell]

^^^

Go away

Disconnected Snorkel this morning, still same.

Low on power, but every setting on Megatune seems OK, MAT, CTS, Spark, Advance, VE advance, TPS etc etc

Only thing was the O2 looked lean, have reloaded the MSQ, difficult to tell, but O2 seems to enrichen more,

frankly I am a tad stumped, can't see it as injector(s) down as BOTH manifolds were glowing red hot

Hmmmmmmmmmmmmmm

Nige

[disco_al]

could be icing in the intake trumpets (i take it you do still have some fitted). whem the air enters the trumpets, it's speed increases as it is gulped in, this makes it cool even further, and then ice forms, resulting in restricted air flow, over rich mixture (possibly) and loss of power.

mate of mine used to experience similar power loss symptoms on his zzr600 bike a few years ago (the one with the srad system) whenever he hit 150mph in cold weather, the trumpets would freeze causing power loss.

could be totally wrong, but it's possible in theis weather, especially if all readings are saying normal....

[Bowie69]

As Ian says, have you had a timing light on it yet? Don't just read the PC screen and say 'everything is alright guv'na' when there could be a single wiring broken to the EDIS unit...

[Turbocharger]

Unresponsive engine - check.

Needs to be booted and revved for power - check.

Door opened with a LR key - check.

Are you sure you didn't get into a Tdi in the work car park by mistake?

[Bull Bar Cowboy]

The MS sends the timing info to the EDIS using a SAW (Spark Angle Word) pulse. The length of the pulse derives the timing and can be in the range of 57.5 BTDC to 10 ATDC. TBH running your engine at 10ADTC would give rise to hot manifolds, but I feel it would need to be more retarded than 10 degrees.

I guess if it was lean & retarded then that would have the same result..............

If SAW is disconnected then the timing will default to 10BTDC ……. It should run quite happily on that, albeit a bit sluggish.

Here is the Blurb from the EDIS technical information,

Spark Angle Word Calculation

The algebraic formula for calculating the SAW pulsewidth is:

SAW Pulsewidth (usec) = 1536 - (25.6 x (desired spark advance in degrees))

Range: 64 - 1792us (57.5° BTDC to 10° ATDC)

Resolution: 4us (5/32nd of a degree)

Example:

You want 29 degrees of advance.

PW = 1536 - (25.6 * 29)

PW = 1536 - (742.4)

PW = 793.6

You would send a pulse that is 793.6 microseconds long to the EDIS module.

The EDIS module will do all the work of timing the spark, you just send the advance pulse.

The EDIS has an advance range of 57.4 degrees BTDC to 10 degrees ATDC. These correspond to the SAW widths of 64 and 1792 microseconds respectively.

[Les Brock]

Lol.....

That Nige fupped then !!

[fozsug]

The MS sends the timing info to the EDIS using a SAW (Spark Angle Word) pulse. The length of the pulse derives the timing and can be in the range of 57.5 BTDC to 10 ATDC. TBH running your engine at 10ADTC would give rise to hot manifolds, but I feel it would need to be more retarded than 10 degrees.

I guess if it was lean & retarded then that would have the same result..............

If SAW is disconnected then the timing will default to 10BTDC ……. It should run quite happily on that, albeit a bit sluggish.

Here is the Blurb from the EDIS technical information,

Spark Angle Word Calculation

The algebraic formula for calculating the SAW pulsewidth is:

SAW Pulsewidth (usec) = 1536 - (25.6 x (desired spark advance in degrees))

Range: 64 - 1792us (57.5° BTDC to 10° ATDC)

Resolution: 4us (5/32nd of a degree)

Example:

You want 29 degrees of advance.

PW = 1536 - (25.6 * 29)

PW = 1536 - (742.4)

PW = 793.6

You would send a pulse that is 793.6 microseconds long to the EDIS module.

The EDIS module will do all the work of timing the spark, you just send the advance pulse.

The EDIS has an advance range of 57.4 degrees BTDC to 10 degrees ATDC. These correspond to the SAW widths of 64 and 1792 microseconds respectively.

Glad ive got a Diesel

[Bowie69]

Yeah, cos your overheating problem took you no time at all diagnose and fix