Just preparing my car for the summer - got it MOT'd etc and have a track day tomorrow

Took the car to have the carbs balanced and afterward gave it a real blast back home. Ran fine for 10 miles at least then car then started to stall when idling and running quite rough and was a bugger to restart. I clean the points, plugs etc just in case.

Took it out for a blast this evening and its doing the same thing. When it is cold it starts on the first or second crank and idles really smoothly. Again after a fast drive the thing starts to run rough and stalls!

Only thing I did notice is when I moved on of the carbs the engine stalled, so I tighted it up a little in the misab plate. Seems to have cured that one, but am at a loss as to what it can be.

Any ideas?? I don't want to look like an idiot on my track day!!

Its a Toyota 4age 16v running on an Omex 150 (distributor) and delotto 45 carbs.

what do the plugs look like?

Is it breathing hot air from under the bonnet, or have you a cool intake?

the carbs should not be fully tightend to the misab plate as they should be allowed a little movement. I had a similar problem and tracked it down to the breather on the tank being blocked creating a vacum. removed the valve sprayed wd 40 into it freed the spring and job done never had a problem after

Plugs looked fine. I have an air scoop, although the carbs don't have a direct feed as such so will be sucking in hotish air. Never been a problem before.

Carbs do have some movement, but looks like one of the nuts was a little loose. I will check the fuel tank.. I don't have a valve, just a coil of fuel pipe!!

I had a similar problem just before Stoneleigh and it turned out that the plugs in it were not up to the job when Hot. They were champion 7's which are not good at high temps, so switched them to NGk 6's and now no problems with hot starts. Worth looking at.

Interesting... I am using the stock 4age NGK plugs. I do have a spare set so might stick them in just in case I have a dodgy one.

Tracked it down to a air leak on one of my carbs..I had changed the misab plates and did not tighten one of the nuts enough!! Now running fine.