11 replies to this topic

[jackson-minis]

hey, been having a problem for a while but it has got much worse since the cold weather has set in. when i accellerate it feels as tho the car is hesitating, if i floor it it will come through like sort of a flat spot then all of a sudden accelerate quickly past certain revs, my setup is a 998 with decked head and stage one kit including freeflow manifold rc 40 exhaust, hif 38 and aau needle. Its hard to describe but it like bogs when accelerating slowly you need to constantly be booting it, the timing is correct and the fueling is spot on on the gas analyser, there is oil in the dashpot, changed the plugs and leads, dizzy cap and rotor arm, im just stumped. Im wondering if it could be the needle because there isnt a gradual point its pretty steep maybe getting to much fuel all of a sudden?? or problem with the carb? but ive rebuilt the carb? could it be something to do with the vaccum system on the dizzy? if anyone could shed any light would be much appriciated thanks
gazz

[minikidx14]

What oil have you used in the carb dashpot?

[tadleysimon]

loss of power under acceleration is normally fuel problems, check the jet in the car isnt blocked and fuel is getting there ok ect ect

[jackson-minis]

cheers guys, i use 10w40 in the dashpot, and have checked fueling at different rpm on the gas analyser seems to be good and getting enough, i have just done a search and found that someone else using a aau needle has a flat spot too could it be the needle? and if so which would be the best to go for? cheers gazz

[tadleysimon]

sounds to me like your best bet is a trip to the rolling road

[jackson-minis]

cheers for the advise mate its just i plan on building the 1310 that i have in the garage over winter so don't really want to spend too much on this current engine
gazz

[RetroRay]

You sure your carb hasnt hit the bulkhead and bent the jet ?

ignore that im an idiot ! just seen your carbs a hif38

Edited by Bakky, 13 December 2009 - 12:51 AM.

[leaky]

Mine does exactly the same as this. Iv been told mines down to it having the wrong carb on it. Does yours do it when your driving along as well or just when you pull away. If I'm driving along a 60 then put my foot down to pick up some speedo I seem to have a slight pause before my engine picks up power. It still does this after having the engine work done and having been rolling roaded.

[minimender]

Could be the piston is sticking slightly in the dashpot or other than that have you tried richening the mixture half a turn to see if that makes a difference?
Gas analyser and rolling roads are great for modern cars but one that has been fiddled with needs the fueling to be experimented with. I believe that if your emmissions are near perfect then it's not getting enough fuel, it's a 50 odd year old design you know. The needle may be slightly wrong or the spring in the dashpot may be a bit weak for the motor.
I once had to stick two springs in a carb to get it to do as the engine asked.

Try and richen the mixture half a turn then a full turn and see what happens, you can allways turn it back out so nothing lost and all to gain.
Also I assume that all the wiring to the coil / dizzy is in excellent order with good soldered connections and sealed with sealant and points are right etc.

Last point is the vac advance, that must be free and working and the timing should be ok and not slightly retarded like some so called experts with rollin roads set it.

good luck with it.

Edited by minimender, 13 December 2009 - 07:23 PM.

[samsfern]

mine ran real ruish after i set it on the emmission machine, so had a fiddle and got it to run right, rechecked emmissions, co was about 8 whatever it is

[minimarco]

Mine is like that in the winter too, my problem was the carb icing.

Just warm it up in the morning, turn it off and let it sit, do other things like put on your shoes or something for a few minutes, then start her up and be on your way.

[lrostoke]

Change the needle to either AAA or AAM, set the mixture to 2.5% at tickover. See how that goes, cured mine straight away, also cured my bro in laws

No rolling road needed.