free hit
engine bog on aceleration - Engine/Ancilliaries - The Lotus Forums Jump to content

engine bog on aceleration

Recommended Posts

Hi folks me again with my aceleration problem, car is 88 carb turbo

when i try to acelerate the car bogs down and wont acelerate until it seems to clear itself then away she goes.

things done so far

new fuel filter and fuel pressure check ok

new plugs, rotor arm and dizzy cap

checked vaccum ok

also checked timing which looks like a little more than 10 BTDC its difficult to tell with angle of view but i could not turn the dizzy any more does this mean i will have to remove, twist slightly and relocate

could this be the answer or is it a carb strip next.

Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.
  • Replies 9
  • Created
  • Last Reply

Top Posters In This Topic

Hi Richard

I take it you checked vacuum at the pump as discussed? Surprised it's not vacuum as you had all the other symptoms to sypport it. So if that's OK, how about vacuum advance?

Unfortunately, if you can't turn the distributor to 10 degrees then you'll have to slip off the cambelt and rotate the auxiliary shaft to a better position. However, make absolutely sure you need to first! The distributor is keyed - not a worm drive.

Checks to make:

Valve timing - make sure all the marks line up

Ignition timing

Ignition advance

Coil/leads OK?

Engine earth?

If all that turns out OK, then carbs tune & balance. If that doesn't work then rebuild carbs.

Feel free to call again!

British Ambassador to Florida, New York, Denmark and Newfoundland.  And Sweden.

Link to post
Share on other sites

How are you checking the spark? snap the electrode off an old plug, that gives it a 3-4mm gap if the spark can jump that it's OK, I like to be able heard it "crack" as well as see it.

Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

Link to post
Share on other sites

If the carbs have never been off for a rebuild I would lean towards the accel pump. If your dizzy has a vacuum advance, make sure it is working. If the problem just showed up overnight I would suspect bad tank of fuel (possible water) in tank. Add a water remover or drain tank.

Good luck,


Link to post
Share on other sites

Good call on the CAT. A plugged exhaust will show its self by feeling the exhaust gas coming out of the pipe. A broken CAT will cause it too be very hot. So hot that trying to place your hand in from of the exhaust outlet will cause you to pull it back quickly.


Link to post
Share on other sites

Thanks to all for suggestions keep them coming all are welcome

there is no cat on my car so its not that problem and i had to have a fuel tank repair so it has got fresh fuel and the fuel filter was replaced after this. Also when i checked my timing you could see the vacuum working.

I purchased my car in october last year with no mot and had been off the road for about 4 years all the brakes were siezed now all done and there was no real gear selection to speak of so i bought a PNM gear change kit this is now done and working,then the drivers side fuel tank was leaking so this was removed and repaired, whilst this was removed access to dizzy was easy so new rotor arm and cap were fitted along with plugs and oil filter and oil.

the car is now has a full mot

The problem is just low down pull off and once it picks itself up will fly, turbo building boost no problem.

I have now ordered a carb service kit and these will be removed and overhauled.

Link to post
Share on other sites

Sounds like the pump jet on one or both carbs.

Take one off and operate the pump underneath the carb, you should get a squirt of petrol. If you don't, that will be the problem.

I had the same issue with mine. Put your foot down and it runs like a VW beetle for a few seconds until you get moving.

Dave Everett

Link to post
Share on other sites

its great to hear what might be my solution but when i check them out they seem fine.

i have now taken the carbs off in readiness for my service kit (currently on order)

and have operated the carb pumps and you can see the fuel squirting.

guess i will just have to wait now for the service kit and see whats inside the carbs then see if it fixes it.

Have also brought silicone vacuum hoses to fit as access is easier with the carbs etc removed.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...