wondering what peoples views are on cold start valves being disconnected?

S2 with mfi management- low compression bottom end, ported and polished head with kent cam and suspected chipped ecu.. ( ive had the ecu cover off but no obvious aftermarket stamps etc).

the cold start valve is disconnected from meter head and blue block connection disconnected, (a few 'tuners' have told me when they're chipped you cant run the cold start???) someone at some point has also split one of the two wires to the valve (blue block connector) and joined into the brown block connector that I believe should plug in directly below inlet manifold (im guessing temp sender)?

my gripe is that its slow to start- first thing in the morning I can catch the revs and hold it at about 1500 rpm and after a few seconds release throttle and its all good. However if I drive somewhere (lets say a 20 minute drive) and come back to the car after leaving it stood for half hour, when I crank it over it will fire up almost instantly but immediately stall again, then when I crank it over a second time it will take a few seconds of cranking before it fires and if you dont hold the revs itll stall....

sorry for the essay guys!

 

any ideas anybody? I would just split the two joined plugs (blue & brown) and plug back to sensors and re attach pipe from meter head to valve and road test but from what I read mfi is temperamental and as the car runs spot on I dont particularly want to start opening up a can of worms just to solve an issue that only affects initial starting! again, thanks in advance...

 

Have a read through the thread by sjieter, rough idle on cold start, sounds like he has the same problem as you in a way, loads of advice on that thread and even a video at the end
Hope this guides you in the right direction

 

Thats mad advice you been given.. chipped ecu can't run cold start.. load of balls mate. Sounds to me that your metering unit needs a little tune and would most probably help connecting that cold start back up if it works at all. I'm guessing this has happened without anything being touched.. So going out of tune over time and weather temps could be the problem.

 

Maybe in a way it's the same but mine doesn't stall at any time.
Hot starts aren't an issue either, fires up on the turn of the key and idles really good.
But cold starts may be the same, keeping an eye on this topic too, as maybe someone may find it

 

ive only recently bought this rs. engine was ballsed so kept my mfi managment and with the help of the sandwich gasket on the inlet bought a efi block and head that had undergone a fair bit of internal work and was running cossy managment (they didnt want to sell me the cossy stuff!)

so basically the cold start was disconnected before we changed the engine.
other than the long crank time before firing it runs sweat as nut so im guessing meter head is ok... Although it wont hurt to check it out.

think ill join up the cold start valve and sort out the spliced in brown plug and see what happens, I guess I can always unplug it again.

im still stumped as to why someone spliced the brown connector to the blue cold start connector???

correct me if im wrong but the brown connector plugs in directly under the inlet manifold, which I presume is a water temp sender for something, would this be ecu temp sensor, I only ask as I can't see a yellow connector which from reading is what should be there somewhere???

thanks for the help everyone.

 

Yes that's correct. The yellow plug plays a key role in the engine working. Without this you have a dead or unreliable engine. Sounds to me them three plugs need sorting and you should be sorted..

 

 

you need to do some research to improve your knowledge before you mess
The brown sensor is a thermo time switch and it's sole function is to control the blue cold start excess fuel injector
This can be left disconnected

 

My cold start failed many years ago ( injecting fuel when ever it felt like) it was disconnected and I've never had any starting problems.

 

turbo systems- my thermo switch connector has 1 wire spliced into 1 wire from the blue cold start switch connector- your view on why someone would have done this? if the thermo switch is left unplugged surely the cold start sensor will not get a true reading? or do you mean leave both disconnected? im nvq trained, just not had the pleasure of working on anything of the cvh age! still a mere pup compared to some

 

essexRSTsouthend- thanks for the pick, very helpful, was wet and cold the other night so I didnt crawl underneath, too much in the workshop to use the pit ill scrabble under and check the yellow plugged sensor. I can see a manual will be needed, can have a good check for continuity from the plugs back through the looms then!

 

leave the cold start injector unplugged the thermo time switch is connected to the cold start injector standard
You are barking up thje wrong tree
You do not need it working it was disconnected for a reason just like many others
There was a ford technical bulletin in 1987 to disconnect it due to over fuelling
There was a modified thermo time switch

LEAVE it DISCONNECTED
The black fuel ecu does cold start enrichment via the yellow ect sensor and the electro magnetic fuel pressure actuator on the metering unit

 

ah ok thats interesting to know, thank you. so as long as the ecu temp switch (yellow) is working correctly it should be fine. runs like a dream once started, its just nice to not have it cranking so long. will have the metering head checked over once we put it on the rollers to make sure its fuelling correctly etc, I intend to remove the metering head and give it a once over as ive noticed a little bit of moisture just bellow the unions which im presuming as the unions are not weeping ther must be a paper type gasket on the top of the head somewhere?

 

I leant towords the two sensor plugs (brown and blue) as someone has connected them with a screw type block connector..