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Hi all,
I'm sorting through a few issues with my '86 f100 efi.
Can anyone tell me what these 2 outlets are meant to be connected to? i think the top one is meant to go to a heater hose, but the lower one I have no idea about whatsoever.
I take it that is the supply & return for the TB heating?
Dave ----
There seems to be no consensus regarding the purpose of the coolant to the throttle body. Some argue it is to prevent freezing of moisture in the TB on very cold starts. Some argue that the coolant is circulated to prevent the EGR gasses from overheating the TB. I'm in the latter camp. However, I have no coolant running to my 1986 truck's TB at all and I'm not fretting about it.
So you believe everything you read on the internet
Just like should the inlet air and base of carb be heated for the same reason.
I am not heating the air intake but am heating the intake manifold because I knew I would be driving the truck in all kinds of weather.
So far no issues and Ihave been out when 20* f
Dave ----
So you believe everything you read on the internet
Just like should the inlet air and base of carb be heated for the same reason.
I am not heating the air intake but am heating the intake manifold because I knew I would be driving the truck in all kinds of weather.
So far no issues and Ihave been out when 20* f
Dave ----
Pretty much, google wouldn't give me false info...
20F is not that cold. I've been driving at -29F. Lot's of old v8's had heated intake manifolds from the heads. So, I'm buying into this one. I recall after blocking off the heat ports on the head of my 340 back in 1975, the car was hard to get it to warm up on cold starts at Pease AFB in Portsmouth NH in the winter.
I can see heating the intake till the motor gets up to temp but then how do you stop the heat is the big question.
The reason for intake heating is to keep the air / fuel a vapor.
If that vapor hits the cold intake the fuel condenses dropping out of the air and pools on the intake floor.
this pooled gas then dribbles into the chambers and the motor runs like crap / rich.
You think it is a choke adjustment and keep messing with it but never can get it right but runs great when up to temp.
The same can happen if you run too large of intake ports and low / idle RPM
The vapor flow is so slow the fuel drops out of the air and dose the same thing as above, dribbles into the chambers.
Seen this happen on a v8 boat motor. At idle when docking or on / off the trailer it would run rich / load up and stall.
Changed out the big port manifold for a smaller one and no more issues.
So there is a lot going on with temp and manifolds / carbs & TB EFI.
Dave ----
