Engine idle problem / acceleration hesitation when cold, Throttle body changed now running out of ideas!! Options

[Fujifilm]

HI

I have a problem that I cant resolve, it started with a rogh idle so I cleaned the throttle body etc. That seemed to cure the problem but it came back, I checked vacuum hoses and they "look" ok.

I took throttle body of again and cleaned it same problem. So to eliminate the throttle body and the two sensors I purchased another second hand throttle body with sensors, installed and the same problem so now I have no idea what to look at. I also changed spark plugs and fuel filter.

The symptoms are....

When starting from cold the car is not very responsive, pushing on accelerator nothing happens then suddenly it will go. It does this until it warms up and then drives ok. BUT when driving with low revs it feels jerky. I can drive for ten miles with no issues, stopping at traffic lights etc. But occasionally the revs will drop so low it nearly stalls. When I get to destination and come to a complete stop it sometimes stalls. Leaving it for ten minutes then driving results in no problems.

The main problem appears to be from cold for about 5 minutes.

Can anyone offer any ideas, the car is a 1995 convertible st202 with 70000 on the clock, its got the one vacuum hose on thhrottle body and pre the extra resonator box.

Just add, I dont know when this started, when I purchased the car owner said it run perfectly but he left an egg cup full of fuel in it and it ran out on my way to petrol station, and it was empty as you possibly get! Could this have affected injectors, I would have thought if it was injectors it would do it all the time?

This post has been edited by Fujifilm: Jul 2, 2014 - 7:23 PM

[VavAlephVav]

Change the fuel filter, and spark plugs, dist cap and rotor first if you have not already.
maybe even check the sock/filter on the pump in the tank since its under the back seat and not hard to get to.(maybe check this last)
and a little seafoam in the gas tank is good too.

if that's good look at the way the throttle body is set up, is the throttle opening diaphragm expanding out. There are two set screw on the throttle body, the one on the diaphragm should be set so that the throttle will be further open than if it were contracted by vacuum.
When the motor loses vacuum the diaphragm expands out and keeps the motor from dying. Special Eddy's got a vid showing it on youtube.

https://www.youtube.com/watch?v=C7a0ejq5be8

then also check out the thread I posted on how to Calibrate the TPS if that is not setup right it will act funny.
http://www.6gc.net/forums/index.php?showtopic=93126