want to alter cold start characteristics

[zen]

feels like its too rich at first cold startup..absoultey sticks the car out with unburnt fuel smell..(tis a 1972 range rover, it does leak,so gases from tail pipe getting in i suspect..)

have checked for fuel leaks,but it ain't that as it would do it all the time and when on lpg (as the fuel pump i keep running)

it takes far too long in my oppion to drop idle down too..

how to modify (/repair?) the cold start crt..its 95 model so no extra cold start injector..

play with the temp senser to ecu maybe, but i dont want to alter it once its warmed up..switching a resistor in parall maybe via a switch..?but thats so crude!

 

[spf_lexus]

What about using a time delay switch? It will kick on with when you first fire it up and wait a pre-set duration to turn off again. I have no ideas where to pick one of these up but they do exist.

Are you running electric fans? If they were installed with a thermostat the engine's ECT will lower your idle sooner with the fans not spinning at all.

 

[sideshow]

dont stuff with tmep sender
all u do is stuff up the rest fo the time
ive never had probs with too much fuel at cold starts
my 1uz used to idle at 1500rpm when cold so i restricted the idle motor pipe
all i recomend is in the big pipe that feeds air to the idle motor
well put a restrictor in this
i think i used a 12mm head nut with 8 mm hole in centre
but u can play with inner id till u get rpm correct

these engine idle too high when cold so i do this to bring revs to around 1200 rpm when first start in morning
helps a shitload
these engines idle so smoothly even when cold anything aorund 1000 to 1200 rpm is still ok
but rememebr playing with the electronics on the standard ecu to trick just the cold start is usually going to caus eproibs once it warms up
u cant have it tricked at cold then ok at hot
unless u have some temp switch cutting resistors in which i think is a waste of time

bring revs down and point yr exhaust down maybe
instead of stuffing with ecu

 

[zen]

hi sideshow..thats exactly why i have not done anything yet...i have already dropped the rpm via the idle air pipe,but used an lpg "power valve" (an adjustable gas tight valve) to alter the air flow..but it still takes ages to warm up..(the termosate is working)..it would not be a real problem even running a switchable variable resistor from the dash across the sender, so acting as a manual choke control, was hoping for an automatic way though..comparator monitoring temp sender voltage and switching resistor in or out of crt would be easy..but worth the effort?not sure?

the other problem is that the 40 yr old tramsmisson has some slack in it, and it really dont like the cold start/warming up cycle (where i suspect it is open loop running on internal set map) as it crashes and bangs on lift up of throttle..its fine once engine is warm and on closed loop (its not the gearbox warming up, as if you let the motor warm up at standstill its fine .(warm engine, cold gearbox)..yes i am going to change the box,but god it weighs alot (4x4 with built in transfer box) and am putting that off..(though i bought one last week..)

 

[litldv8]

try putting 6 inches of exhaust tube on the exhaust pipe
just have a straight piece flared up and put a single tex screw in it to try
what is it idling at cold
neil