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Although your temperature gauge may show that it works, some models have a second temperature sensor for the engine management system. That second sensor provides info which sets curb idle and timing advance. The "Cold start" feature is a part of this. The hic-cup is something of a bucking symptom as the engine controls toggle between hot and cold run settings repeatedly as water temperature is not stable. In the past, I found several 1984 engines having defective thermostats which are tied into "Step-up" solenoids for the curb idle. What happens is idle speed is suppose to drop when the engine is hot. When someone adjusts the curb idle while the engine is on the "cold setting", the setting(rpm) will be too low once the engine has heated up and the part drops to a hot setting. So to clearly define your problem, you have 2 stemming from the same defects. The "in motion" problem is caused by timing changes based on temperature and the "idle" problem is caused by improper adjustment of the curb idle solenoid because of unstable operating temperature. What you want to do is change your thermostat. This will give you a stable temperature. Then let the engine heat up and you should notice a "click" and the engine should idle down. It may stall. Then turn the idle rpm up until the engine will not stall. The hic-cups should disappear once the operating temp is reached. If you still have problems then look for the water temperature sensors before replacing expensive parts.
Remove the gas cap,and then remove the return fuel line off the back of the throttle body.Now take a air hose and blow in the line you removed to make sure it is not clogged up,you should be able to blow back threw the tank easy with compressed air.If you are able to,then replace the fuel pressure regulator on top of the throttle body.
The fuel mixture is wrong because either the carb is badly adjusted or the choke doesn't open fully when the engine is hot.
Take the carb apart and check every single component, starting with the choke plates and the level in the bowls.
I have an 87 Comanche and it's the same way. If it ever gets too hot or too cold and won't start, try slipping it to neutral. As far as having a high idle and a long crank time, i'd suggest giving it a tune up and changing out your plugs.
Having the proper thermostat in fuel injected vehicles is very important.They have a engine coolant sensor to tell the computer the temp of the coolant. If the engine is running too cold,(or cold all the time), the computer is going to tell the idle motor to raise the idle and to give it more fuel, which can damage the cat converter. These vehicles need a 192-195 degree thermostat. Also check the TP sensor (throttle position sensor for proper voltage) the green wire should read .7 to 1.00 volts.
Here are a couple things to try. The idle surge is a common problem. Ford makes an adjustable plate like the one below. It allows come control over your idle. I made one and it eliminated most of the surging. I think the Ford part is about $30. Can't seem to find the ford part number though. Search online.
Try www.fordfuelinjection.com or other ford sites. Lots of great information.
My 89 seems to roar loud when cold when coming back down to idle and I am sure its the fan clutch. I have also heard the water temp sensor can cause idle problems because the EEC does not know what state the engine is in. (hot/cold, etc)
Hope this helps. I do recommend the adjustable plate though.
IF IT IS IDLED TOO HIGH THIS WILL CAUSE IT
you have some carbon buildup on pistons which is normal
the carbon gets hot and ignites the fuel and is why the engine "runs on" if it is idled too high it makes worse try running some top engine cleaner or sea foam thru engine and adjust idel