[Diy_efi] Re: Diy_efi Digest, Vol 9, Issue 13

[Ian Molton]

Bill Washington wrote:
> Ian,
>     The cold start mechanism on my diesels is mechanical, ie a cable to 
> a lever on the side of the pump - that lever controls a mechanical 
> advance in the IP - I have now seen this on Bosch, Roto-diesel and Lucas 
> Diesel injection pumps.

Well, my IP has only one protruding 'control' of any kind - a spring 
loaded lever, attached to the throttle cable.

theres just two vaccum actuators that also affect the lever. One is the 
cold start rev boost, which is vacuum actuated, but controlled by a 
solenoid valve from a button on the dash. The other is a 'dashpot' and 
controlled by vacuum from the airbox.

neither of these moves *at all* when the idle increases. nor does the lever.

Theres also a vacuum actuator on the top of the pump which is the boost 
compensator.

It appears that the engine *always* starts with the right idle speed. if 
its warm, then a few seconds (10-20) later, the idle will increase.

 > the same function could be done electronically,
> and probably was on some the generation after mine ... and then.... in 
> the new common rail diesels its all done in a computer and the injectors 
> have changed to electronic and the IP is simply a 'very' high pressure 
> delivery system.

Theres nothing electronic on my IP other than the fuel cut relay and rev 
counter pickup.

>     I would check the resistance of your temp sensor(s) hot and cold  
> and compare them the the manufacturer's spec.

surely disconnecting them would have an effect on the problem?

either way, they all appear to be good.

this is one weird problem.