I have an 87 aerostar with the 3.0L. engine and 110,000 miles. The engine is hard to start and idles rough and seems to be lacking power. I just got this vehicle a few weeks ago, changed the oil & filter and air filter, replaced the battery, changed the O2 sensor, dropped the fuel tank, replaced the inlet neck (leaking), ran "Guaranteed to Pass" through it (it failed emmisions). It passed with flying colors after that. I'm only getting about 19 MPG highway.
The previous owner, my brother, had to replace the transmission a year ago as the vacuum switch failed and pumped all the transmision fluid into the engine and killed the tranny. (this happened to the guy he bought it from)
My other brother ran his scanner on it, it came back with the following faults: KOEO (Key On Engine Off) DTC 95, Fuel pump secondary circuit fault. KOER (Key On Engine Running) DTC 6 Cylinder Number; DTC 12, RPM at idle out of range/high; DTC 77 Operator error during Dynamic Response Test / Wide Open Throttle not sensed. We tried the test three times, even removed the mat to ensure getting the gas pedal all the way down during the goose test. Does anyone have any ideas what to do and where to start?
Thanks,
Mike Berg

 

Hi Mike:

Welcome to our FTE forum

 

Mike! Looks like your van is over 500K...... ]

Well. May be it was not maintaned well....

What to begin from is Timimg. The second is to check mixture. If she fails emmision test, learn why she does it? To mucj CO (reach mixture); backfire, missfire and to much CxHx - lean mixture, bad spark plugs ore ignition timing is not correct.

Check compression. Look, is there oil in cylinders during test?

 

is the problem cold or hot start and idle?

with that much ATF being sucked into plenum, I would suspect contamination of the MAF and IAT, clean both...shot glass full of TB cleaner
clean throat and backside of TB and it's plate, air gap is critical to proper idle, use TB cleaner toothbrush and old lint free white T shirt

that much ATF probably damaged and softened all the vacuum lines...look for split and blown off vac. lines...don't forget the vapor canister vac. line

may be coked plugged ring pack with carbon buildup from the ATF behind the rings preventing proper seal and compression and/or carbon buildup in combustion chamber....do a Berryman B12 full can thru TB plate hole with 1/8" tube at 2k rpm into hot engine, let set 2 hours and out to freeway for hard 20 miles run...followup with 1 qt of water via same method

borrow or rent fuel pressure tester...should measure min 30 psi at idle....Autozone and many parts stores loan out special tools for free
pull off vacuum line to regulator and look for any gas=failed regulator
new fuel filter

if no improvement, then new plugs, wires rotor and cap
disconnect neg. batt. lead after each major change to clear KAM of old incorrect parameters and ECU will relearn new correct....also clears codes

clean the injectors with full bottle of Gumout Regane or Chevron Techron Concentrate or Pure in 1/2 tank of gas....no cheap weak substitutes....these 2 work....polyetheramine....the best

 

Solvent is good too.

 

Thanks, 96_4wdr. The idle is rough and hard to start warm and cold. I will start at the top of your list and go from there. The spark plugs were replaced when the tranny was, and it has 10k miles on it since.

Thanks, Mike