Cold start
 

hi all
i have managed to move the 2 ball stop adjusters on the throttle and kick down only a bit and now the revs don't shoot up by the 200 rpm which they should do when engine is cold .the cable does move when engine hot and cold as you can see postion of crimp on cable . i have not touched anything else so i don't know really what i have done now, i did it because i was trying to make kick down cable a little more tight as it felt a bit slack but not much so then i moved the cold start stud too and wound the plastic nut on the throttle cable that goes round to pedal , the cold start only comes on by about 100 rpm .
im sorry i did this and won't touch it again if i can get cold start fixed
regards jim

If the idle is increasing by only 100 rpm rather than 200 rpm, that is no big deal really, as long as the main advance function of the cold start is still working well and the car starts and idles smoothly when cold. 100 rpm should be OK.

If you want it to kick the idle speed up a little more though, all you would have to do is make a slight adjustment of the position of the ball stud on the top of the cold start lever. The same one you already were moving before, right?

It may take a few tries to get it where you want it. Idle too low is better than idle too high though. So unless it bothers you, you may wish to just leave it as is, again it will not hurt anything like this. If you do raise it, do so in very small adjustments. You don't want to have the engine racing just after a cold start, nor do you want to be having to engage the transmission with a too high idle.

Remember also you do not want to touch the cable portion of the cold start system since that is a bench calibrated adjustment that you don't want to mess with. Only do it using the position of the ball stud. ;)

thank you V8VOLVO .i have not touched the short bit of cold start cable with the 2 screws and nut to keep it in place ,this may have been messed with before years ago not by me . a friend who is very good with these cars but lives a long way from me said if the cold start is not working right .i need to try and get the ball stops in the correct positions but its trial and error a bit looking and listening to the sound of the engine , and slightly adjusting ball stops . im sure MPG is well down now and lack of power off too the pump has not been touched im sure so its all to do with the throttle ,and cold start set up the kick down will come in at say 40 MPH if i floor it but not at say 55 MPH . there is a slight jolt in low gearing on excelaration . the slight leak is still there on the bottom of cold start too .im thinking of a final trip to the diesel engineers at the moment ,

forgot to say plenty of blue smoke on start up but goes away after 30 seconds and car is lumpy due to lack of cold start ,but starts 1st time alway , the lumpy engine could be down to glow plugs ,as i still need to replace 5 and 6 . maybe 1 is weak now or both are weak ,
regards jim

You are right that if it has even just one dead glow plug it will make cold starts a little rocky and smoky. However, lack of timing advance and/or loss of fuel pump prime after sitting, due to leaks, can have the same effect, so more troubleshooting would be required to know what is at fault for sure.

Note that there are two separate (although related) functions of the cold start system: 1) advancing timing and 2) raising idle speed. They both work on the motion of the same lever, but the timing function (1) occurs internally inside the pump based on the rotation of the shaft that the lever is attached to, whereas the idle boost function (2) works externally, based on the contact between the cold start lever's ball stud with the tab on the bottom of the main throttle lever.

Hence, some adjustments you might make would affect one function only, whereas others (such as changing the setting of the cable) would affect both.

If the cable position didn't change, and the only thing that was moved was the ball stud, then the timing advance part (1) should still be working as it was. That is good since it is the more important part. The idle speed increase (2) is controlled by the position of that ball stud and it sounds like that is not having as much of an effect as it used to, but that doesn't matter as much.

That said, if the engine power is still weaker than it used to be, plus worse MPG, plus difficult cold starts, plus fuel leaks, then I agree a return trip to your diesel mechanics would be a good idea. Maybe tell them this time you do not want to pick the car up until it is 100% right and they can take whatever time they need to repair it fully. ;)

And once more, consider the idea of having the pump fully resealed and recalibrated. This will cost more, but you would only have to do it once, and when it goes back on the engine (assuming timed correctly) it will run precisely like it's supposed to and no more fiddling will be needed anywhere. Cold start timing and idle increase settings will be exactly right, power level and response right, etc. And with the pump removed you can also easily access #5 and #6 glow plugs for replacement if that is needed. Up to you but this is the way you could do it that would solve all issues in one fell swoop.

smother gear changes
 

thanks for advice .well i have moved the higher ball stud out a good bit , and now driving the car the auto box changes up a lot smother in in low gears on acceleration so that is better , .leak has got no worse only a little wet ,but no dripping diesel , i notice revs just about get up to 3000 going up hill with foot to the floor so this reflects on power loss .

That number is worthless without additional data.

What speed is this happening at?

How many gears has the auto trans automatically downshifted when you mashed on the pedal?

What happens if you manually downshift when flooring it uphill?

I am not convinced this is not related to the kickdown cable misrouting/maladjustment.

Here's something else for you to try: (engine off) Have a helper press the accelerator pedal to the floor while you watch the accelerator arm on the IP. While they are holding it to the floor, see if you can rotate the accelerator arm on the IP even further. Is the pedal able to rotate the throttle arm all the way by itself? Maybe there is too much slack in the pedal cable or other (max WOT?) adjustment?

thanks for that info NGOMA i have done your test there is only 5 millimetres max when pedal is full down and i can just get that tiny bit more turn . the maximum RPM is never more than 3000 going up my hill with foot on the floor .
and my fuel consumption is down by 15% i guess !

15% less fuel consumption is quite a good move-- what do you think it is you did to improve it that much? How have you been measuring it?

Otherwise-- Sorry I don't have any more advice for you, based on the information given.

sorry guys
that was meant to read 15% worse MPG im thinking it is possibly more as fuel gauge is dropping quite noticeably from fill up .
well i called in at garage today they were to busy to help at moment i explained
loss of power and higher fuel consumption . they said those 2 things suggest the
fuel adjustment will be out as you guys said its a matter of adjusting score in 1/8
of a turn increments and driving the car then working on this principal you can get the car running correctly i am going to go with this as nothing to lose if i take care and do it the way you guys say . what do you think?