Author Topic: T2 with lag??  (Read 3835 times)

penfold1981

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T2 with lag??
« on: 21:12, Sun 30 August 2009 »
When changing gear while driving hard there is a noticeable amount of lag, surely this isn't right?

Could this be an actuator issue?

also, if I'm driving up to a junction in second gear with my foot off the throttle, when I put my foot back on the throttle I get hesitation, a bit of a stutter, like what happens if you drive without the choke on when it's cold.

So two problems really. Nothing major, just thought I'd ask :-)

Brigsy

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« Reply #1 on: 21:51, Sun 30 August 2009 »
Possibly boost leak or fuelling needs looking at.

5teve L

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« Reply #2 on: 22:26, Sun 30 August 2009 »
As above, sounds like carb may need tweeking..

penfold1981

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« Reply #3 on: 01:02, Mon 31 August 2009 »
can you be a bit more specific please. is this a lean or rich issue? running standard boost, standard turbo, standard engine so shouldn't really need anything doing unless I suppose the carb could be worn out.

jayy.cfg

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« Reply #4 on: 23:46, Mon 31 August 2009 »
try adjusting the adjuster on the side of the carb 1 nearest to the drivers side lock it up so u cant twist it then do 2 n half full turns that is ment to be how it ment to be set up, i had this problem wi a lil lag did that and i cudnt notice it no more and if u do have it still try a extra alf or full turn
and that shud do it. if its the mixture problem, if nt like above check for leaks in ur boost pipes if u ave the std pipes as there known for leaking or pipes to dv if u have 1

penfold1981

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« Reply #5 on: 23:54, Mon 31 August 2009 »
I set the idle up on a gas tester, lambda was at 1 which is spot on but I opened it up about 1/8th of a turn to richen it, keep it safe :-)

I have adjusted the accelerator pump so it opens a little earlier which appears to have helped a little or maybe I'm just imagining it!

Will be getting an afr gauge in a few months so that should make things a little clearer.

Will check for leaks around hoses/dump valve etc.

Also got a collins actuator on it's way so should hopefully have the problem sorted soon.

James5

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« Reply #6 on: 00:05, Tue 01 September 2009 »
To correctly set the accelerator pump arm you need a 4 or 5mm drill bit end to give you the correct clearance space (place in the venturi against the grove and let the throttle butterfly rest on it) then adjust the pump rod screw so that the pump arm is fully pushed in when the drill bit is in place.

penfold1981

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« Reply #7 on: 16:38, Tue 01 September 2009 »
oh yeah, also when the engine is at idle if I press the throttle pedal fast to the floor there is also a short pause before anything happens. It's gota be fueling related.

James5

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« Reply #8 on: 16:48, Tue 01 September 2009 »
Quote from: "penfold1981"
oh yeah, also when the engine is at idle if I press the throttle pedal fast to the floor there is also a short pause before anything happens. It's gota be fueling related.


Does sound like the accelerator pump jet arm is not set correctly.

penfold1981

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« Reply #9 on: 18:14, Tue 01 September 2009 »
I have just set the arm and still same fault :-(

But I have just put a piece of tube on to the inlet on the accelerator pump and if I blow down it there is no resistance, is this right? Can someone check or does someone know?

Accelerator pump is pumping fuel because I could see fuel coming out in to the carb when I was adjusting it, just thought that maybe with it being connected to the vacuum system it may use that like the servo on the brakes does to assist it when you put your foot down.

penfold1981

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« Reply #10 on: 18:17, Tue 01 September 2009 »
update, when I move the throttle while blowing down the pipe I get a bit of resistance.

I'm thinking split accelerator pump diaphragm.

Seems to me that would explain the lag when changing gear and the stuttering/judder when applying throttle at low revs.

I will get a rebuild kit and see how that goes.

penfold1981

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« Reply #11 on: 17:07, Wed 02 September 2009 »
Thanks for all the help and suggestions so far guys.

just had the accelerator pump off the car and there's no splits or leaks in the diaphragm!!

I have re-adjusted the length of the rod but still get the same hesitation and judder. At part throttle it accelerates fine, it's just when I floor it there's the issue. Only happens between idle (800rpm) and about or just over 1000rpm when the car is stationary and the revs are a little higher when it happens while driving.

I've done some research and it's displaying the signs of a faulty accelerator pump but it just isn't faulty.

Any more ideas?

r5matt

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« Reply #12 on: 17:45, Wed 02 September 2009 »
Have you tried a Carb over haul , some times the bottom of the carb gasket that sits on the inlet mainfold can split Causing a great amount of air being drawn in ? a service kit is around 25 pounds Worth a look ?

penfold1981

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« Reply #13 on: 17:55, Wed 02 September 2009 »
looks like I may end up replacing the carb base gaskets just to rule it out.

for some reason I'm missing the spacer from below the carb but can't imagine that would cause any problems.

James5

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« Reply #14 on: 20:06, Wed 02 September 2009 »
What size is your 1st stage jet??

The 1st stage (the removable screw in jet that is inside the triangle enricher section) is only 1mm as standard - if this has been increased then it'll get too rich when you give it alot of throttle, before boost comes on. Some tuners used to swap this jet around with the a/c! cheap skates, it made the fuel curve bloody horrible.