dash pot oil low?
Turbo Mini Forums

Hi im running a 1293 with a T2 turbo and phase 2 cam. Last night after a couple of hours driving my car seemed to die out if i opened the throttle more than say half way, it was as if it was sucking in to much air and leaning out. After stopping at service station and fiddling I topped up the dashpot oil with 20w50 and set off the car was perfect again. Then about 50 miles later same thing happened again so once again topped up the oil and it was cured.

This happened a third time before finally reaching my destination just wondered if anyone had any ideas what could be causing this?
Bearing in mind the car was running perfect to start with.

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Turbominis Worst Advice winner 2006, get in

the probable cause will be worn daspot plunger

but... have you tried a stronger uprated dashpot spring or two wound together

i suspect that the dashpot is been forced upwards too quickley losing all the oil.

compounde by the T2

just a thought!

so i can use any two dashpot springs wound together?
I do have a spare plunger which i could give a try to.
Just topped up the oil before taking someone for a spin up the road and back at full throttle and it had gone already!?

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Turbominis Worst Advice winner 2006, get in

How much are you topping it up to? It does not need to be all the way to the top, just to the top of the piston rod which is visible with the cap unscrewed.

ah right i was just topping up all the way which seemed to cure the problem until i start going full throttle which shortly after it will re-occur.
Its ok at half throttle but at full throttle it dies out.

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Turbominis Worst Advice winner 2006, get in

Is this something that has just started in cold weather? Could it be carb icing? If you are driving and it dies, if you stop for 5 mins and then set off again without touching dashpot oil level is it then OK?

Well i haven't been running this engine long so i couldn't comment on the cold weather. It only dies out while the throttle is held open it will run fine at lower revs. Ill try stopping for 5 mins tomorrow when no doubt it happens again!

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Turbominis Worst Advice winner 2006, get in

my above thread would be probable cause

cant you smell burning oil or anything? sounds like its just leaking out, but i have no doupt you would smell it burning on the turbo...


edit - could it be maybee a seal int he carb and it be burning it?
any blue smoke?

Dan

Edited by pot_dan on 20th Dec, 2005.

i cant smell any oil burning. I have put a different piston plunger in but haven't been out for a run in it yet as im working on the brakes. It seems to leak away very rapidly, does the dashpot have a seal apart from the fibre washer on the top?

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Turbominis Worst Advice winner 2006, get in

i am unsure about the seal, i know you can take the dashpot off with the 3 screws but i havent rebuilt a carb before so dont know were the oil is held in, maybee if you take it to bits urself it will reveal itsself:)

hth Dan

Sounds as it's either leaning out or flooding, doesn't it?

thats what i thought, I just changed the dashpot plunger went out in it and after overtaking one car at full throttle in third as soon as i shifted to fourth it started. Pulled over and the dashpot appeared to have a tiny amount of oil at the bottom. Going to take the top now have a look try a different spring

I forgot to mention if back of the throttle for say a min i could then go full throttle for a small amount of time before it started again!?

Edited by slim_shadyuk on 21st Dec, 2005.

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Turbominis Worst Advice winner 2006, get in

update: just took the dashpot off and would i be right in thinking the turbo HIF 44 has an o-ring seal? there was a seal fitted but it was too big and not seated properly looks like one off a float bowl!
Also compared the spring to a N/A one from a HIF 38 and was shorter but perhaps this is because it is stiffer?
Anyway going to try two springs wound together and source a proper size o ring

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Turbominis Worst Advice winner 2006, get in

right slim have you tried the T peice trick?

i think you may be confusing this problem some how! with going down the wrong route.

do a search on the T peice trick by
TURBO DAVE!

oh! dont for get to fit a stronger dash pot spring
or wind two togeather

ithat was already in place i actually just took the t-piece off to see if there was any difference!
Yes wound two together so see what happens tonight, lets hope it works!

Edited by slim_shadyuk on 21st Dec, 2005.

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Turbominis Worst Advice winner 2006, get in

I suspect that the dashpot oil thing is a red herring that is throwing you off the real problem.

Have you checked the base fuel pressure, and that it is rising correctly with boost pressure?

i agree Tom i tried two dashpot springs and no difference i guess the time taken to fill up the dashpot was just as good as pulling over for 5 mins like you suggested!
The fuel base pressure was 3.5 bar when i checked it a while ago but never checked to see if it was rising.
I drove 250 miles last friday night, it happened twice then, now its more like every ten minutes!
I dont want to sound like im jumping the gun but could it be ignition system breaking down?

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Turbominis Worst Advice winner 2006, get in

3,5 bar??? That is 50psi! Sure you don't mean 3,5 Psi which is SHOULD be?

Ignition shouldn't break down after ten minutes. This has got to be fuel starvation.... Get a fuel pressure gauge hooked up between the carb an regulator and follow Toms' advice.

Yes i meant 3.5 psi.
I'm getting a pressure gauge now and going to check as Tom suggested

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Turbominis Worst Advice winner 2006, get in

Topping the oil up too far can cause it to suck it out very quickly. try putting less in.

ok i've now checked the fuel pressure and at idle is about 0.2 bar peaking at 0.5 bar at 6.000 rpm.
Also worth noting is whilst having this problem my boost gauge has been broken and after replacing it with a newly aquired xmas pressie it is only showing 0.1 bar boost at full throttle. You can hear the turbine running and what sounds like air surging so is it possible im loosing boost pressure which could be source oo the problem?

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Turbominis Worst Advice winner 2006, get in

0.1bar boost? That is 1.4 psi. I can fart harder than 1.4psi.

You certainly need to investigate where your missing boost is I'd say......

boost hose off, fooked over boost valve, split in boost hose, actuator arm off etc etc