yo Z,
That is a killer read-out for sure.
re:
surging idle and stalls when ideling.
car is 80 mod bronco with a
c6 gearbox,
Engine is a
89 5l EFI engine,
efi swap not done by me and looks like a bag of snakes.
i think a lot of the codes are gearbox related due to the ecm has 89 302 efi e4od.
Yep, that's really pop some of the tranny control codes out for now.
Any other symptoms before this began?
All that stuff will def give you all kinds of false and maybe a few good Codes that are applicable to da symptoms; so let's concentrate on vacuum leaks and the diff in the PCMs and how they read the sensors;
Vacuum leaks; intake manifold, vacuum hoses, vacuum reservoirs (EGR Sys & Vacuum Tank (plastic ball type); Air Cond control ckt under dash & to heat/blend/etc. doors, power brake booster, cruise control ckt, etc.... where applicable.
at idle da vacuum should hold steady around 18-22 in-Hg &
"...Rev it up to ~2500 rpm, hold it steady, and you should see the needle drop, then slowly increase to a level close to the idle reading (though slightly lower is normal)..." by SigEP
Do you have a vac gauge?
pic in an 83 by Steve83
It's one of the Best under $10.00 diagnostic tools that I've ever used.
Vacuum Gauge Diagnosis by Craig U at
http://www.classictruckshop.com/clubs/earlyburbs/projects/vac/uum.htm
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This is from a TSB for a later year, but this specific info is applicable.
The following is a list of vehicle symptoms which have been associated with the
TPS, but can also be related to other vehicle components. Check engine light, Stalls, quits, hesitation/stumble, fast idle; To minimize the replacement of good components, be advised that the following non-EEC areas may be the issue: Excessive blow-by,
PCV malfunction, Vacuum leaks, Fuel pressure, Throttle sticking or linkage binding.
Closed Throttle can be anywhere between 0.6-1.0 volts
Now here is Ford's statement on testing;
the UPPER CASE is by Ford, not me..ok?
"...MANY VOLTMETERS WILL AUTOMATICALLY CHANGE RANGES WHEN MEASURING TPS OUTPUT FROM IDLE TO WOT. WHEN A VOLTMETER IS USED TO MEASURE TPS OUTPUT FROM IDLE TO WOT, THE METER SCALES OR CHANGES RANGES AUTOMATICALLY. THERE MAY BE AN ERRONEOUS METER DISPLAY UNTIL THE VOLTMETER HAS LOCKED TO THE APPROPRIATE VOLTAGE READING. THE ERRONEOUS METER DISPLAY DOES NOT REPRESENT A DEFECTIVE TPS. NOTE: IT IS RECOMMENDED THAT THE "RANGE LOCK" FEATURE ON MANY METERS BE SET FOR CHECKING TPS VOLTAGE..."
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Next up is da IAC;
ive cleaned and tested the IAC ,engine totaly refuses to idle when its diconnected, so it has to be ok i guess. That's correct
Testing may be achieved by bringing the engine to operating temperature, noting the idle speed (should be within spec). Unplug the unit’s electrical connector, and the idle should drop to about 650 RPM. When the unit is reinstalled, it should return to normal idle speed. If the vehicle does not idle at proper RPM (too low), there are no vacuum leaks, and the TPS calibration is correct, than the unit is most likely fault
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I guess you went thru a lot of the following since you stated a lot of the info in your post, but I did have some sludge inside the IAC on my 96 that set-off a code for the IAC.. it was sorta like a strand of hair that gets gucked upin a drain... inside the TB IAC port.
BTW, were these Ford MotorCraft parts?
There are many folks that are coming up with BAD QUALITY/out of spec & / or non-fitting sensors, ignition cylinders, DFPEs and now air filter elemnts and so-on....
Overview & Testing; "First let me say this little thing has many names. But they all talk about the same item under the hood. Here all the names I’ve had the torture of learning throughout the years: Idle Air Bypass •Idle Air Control •Idle Speed Control •Throttle Bypass Air •Idle Bypass •Inlet Air Controller •Inlet Air Bypass •Intake Air Bypass •Intake Air Control..."
Source: by Ryan M (Fireguy50) at
http://fordfuelinjection.com/index.php?p=39
Esp;
"...When you take you foot of the pedal the IAB is at 100% to prevent stalling.
•As the engine returns to
idle speeds the IAB lowers the duty cycle to keep the RPM stable.
•
When the vehicle comes to a stop the IAB is now controlling the Idle..."
READ MORE there
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Idle Air Control (IAC) Sludge; Poor Idle TSB 91-25-07 for 85-92 Bronco & F Series & many others; "...Hard cold starts, hesitation and stalls on initial start-up or during idle or decel
may be caused by sludge in the throttle body and/or idle by-pass valve. Sludge deposits or oil film on the throttle body bore and plate or the idle air by-pass valve may cause one or more of the following conditions. Hard Cold Start, Stall On Initial Start-Up
, Stall During Idle, Stall During Decel, Rough Idle, Rolling Idle, Hesitation During Acceleration. A new idle air by-pass service kit (F2PZ-9F939-A) is now available for service use to correct sludge contamination concerns of the throttle bore and plate only. It eliminates the need to clean the majority of past model throttle body applications. Cleaning is not required on sludge tolerant throttle body designs released for 1991 and newer model years..." READ & SEE Much More
Source: by Ford via Steve83 (Steve, That dirty old truck) at
http://www.supermotors.net/registry/media/724437
A vacuum leak is one of the most common causes and can be checked with a vacuum pump
