Minimum RPM before start?

[Dr Sheldon]

If only everything was that quick/easy/cheap to fix
(If you can technically call it a fix)

Good to have a Brit onside - These ermm Highly strung - First word is Sue

Where are you in this beautiful isle ?

 

[Dr Sheldon]

Having said that... I was in a friends car (Early 80's Ford Cortina MK5) which we had parked and switched off about 2 hours earlier. It had a tendency to run-on a little after the ignition was cut, so he would let the clutch out to stop the motor faster. When we got back in, he switched on the ignition, grabs the gear lever to put it in neutral... pressed the clutch in and it make a single ignition knock sound and then sat idling... without the starter at all. Hahaha! I assume there was just enough compression to move it enough to fire a spark plug when he pressed the clutch

The Cortina had a clutch position sensor

You see @jackofromtheuk - @NZDubNurd is in total agreement with you !!

Or is he doing what i am too kind to do ??

I reckon he ripping some one a new one ?

 

[Dr Sheldon]

I think that for a normal engine start it is necessary: 1.Normal compression 2.Normal pressure in the fuel system 3.Normal starter rpm 4.The voltage drop on the battery is not lower than 9.5 V5.For diesels,a serviceable spark plug system.Only under these conditions will the engine start easily.

You forgot something - IMMO

DEFINE Normal ??

 

[ED30R]

Good to have a Brit onside - These ermm Highly strung - First word is Sue

Where are you in this beautiful isle ?

I’m Irish ROI but lived in uk nearly 40 years. Im just outside Brum

 

[Dr Sheldon]

I’m Irish ROI but lived in uk nearly 40 years. Im just outside Brum

An hour up the M40 ?

I will be in Coventry at the Top Technician Awards Oct 26th (Hilton Double Tree) if you fancy a beer -

 

[SaVAGeSoot]

Found your post here.

But note the date on that Tech Tip: 2001. That was a different era; distributor pump engines. It's anyone's guess whether that's applicable to modern common-rail types.

-Uwe-

That is correct, and I believe I even "disclosed" that fact in another post at some point.....

But, from my logic, any TDI is still a compression engine, and as such, will still require some "basic" RPM in order to both generate sufficient heat (and not just rely on GPs... if ambient conditions are such that they actually activate them) and to generate enough momentum to overcome the engine assembly's rotating enertia while allowing the HPFP to generate sufficient pressure to satisfy ECU requirements for injector firing....

Sure, things will be slightly different on a gasser where we have plugs to fire based on crank angle even at lower RPM, but most of the other stuff still applies to some degree.

I believe not that long ago, VAG made it a little more difficult for those without access to servicenet to find all these TSBs and TTs, so these days, unless you have full access to erWin and vwGoogle or whatever they were calling their "special" search engine, it's a little more difficult to find the exact documents that apply to each specific engine\model.

 

[SVD]

Surely you mean a serviceable glow plug system. Diesel engines do not have spark plugs.

-Uwe-

Yes, exactly.

 

[SVD]

https://imgur.com/a/JLFEWyo

The idle speed of the starter is 2500.The number of gear teeth is 11,the number of teeth of the flywheel crown is 128.128/11=11.642500/11,64=215It turns out that for a confident start of the engine, you need 215rpm

 

[Dr Sheldon]

https://imgur.com/a/JLFEWyo

The idle speed of the starter is 2500.The number of gear teeth is 11,the number of teeth of the flywheel crown is 128.128/11=11.642500/11,64=215It turns out that for a confident start of the engine, you need 215rpm

Absolutely agree but all futile now !

OP @jackofromtheuk has fallen off his high horse !!

We see the likes of him come and go - No Substance !! SAD !!

Good use of the language and excellent sentence structuring skills however let down by the Tantrum within !!


Lets all hold hands and wish him the best !!

 

[PetrolDave]

for a confident start of the engine, you need 215rpm

For that particular engine, it's not the same for all engines - which is the key point this long discussion has highlighted IMHO.

 

[Mike@Gendan]

Absolutely agree but all futile now !

OP @jackofromtheuk has fallen off his high horse !!

We see the likes of him come and go - No Substance !! SAD !!

Good use of the language and excellent sentence structuring skills however let down by the Tantrum within !!


Lets all hold hands and wish him the best !!

I'm intrigued.

Are you being deliberately obnoxious, or does it just come naturally?

 

[SVD]

For that particular engine, it's not the same for all engines - which is the key point this long discussion has highlighted IMHO.

That's right, it's for this particular engine.But the same principle can be used to calculate the RPM for other engines.If there is a need and desire, of courseThe calculations were given solely as an example, without claiming anything.

 

[SaVAGeSoot]

Can't we all just get along? (I literally can't believe that I'm the one saying it)

 

[Uwe]

Can't we all just get along?

Bah, perhaps we could argue over what car wax, or what motor oil is best?

-Uwe-

 

[jackofromtheuk]

No I'm still here. Cars still starting at sub 180rpm. Anything specific questions I'll try respond if I see it but no promises

Edit: didn't see the most recent post. I'm happy with the Admin thread lock been applied or just deleted from existence. I proved it myself so not sure we need to discuss any further.