86 ranger 2.9 weird idle and miss need help pleasex

[Mike205]

Before I start here is what all has been done
-new fuel pumps and filter and fpr
-new distributor with plugs and wires and tfi module and coil
-upper and lower intake gaskets
-tps,idle air control,map,coolant temp,air inlet temp sensor and O2 sensor
-egr valve
-pcv valve and new breather
-new computer

Also used the old rubber air filter cleaner hose and put a cone filter at the end of it.

Codes while running
-12 can't control rpm during high rpm check
-23 tp sensor out of range
-24 intake air temp out of range
-42 Rich exhaust bank 1
-31 egr out of range
-13 can't control rpm during low rpm check
-25 no knock signal

Codes not running
-23 tp sensor out of range
-54 air charge temp signal high
-31 egr out of range

 

[RonD]

Welcome to TRS

Since you are getting codes from computer, computer should be OK, but may be the problem.

Computer and sensors are all electric, so......................wiring and Grounds are a BIG deal, especially when you have multiple codes.

One thing to check first, the computer sends out 5volts to multiple sensors, if that voltage is wrong then all those sensors would be "out of range".

Those sensors include TPS, IAT(intake air temp), knock and EGR from your list

But ECT(engine coolant temp) sensor is not on the list and it uses the same 5volts, so that is odd.

Anyway check for 5 volts at the TPS(throttle position sensor).
Set volt meter for DC Volts, black meter probe to battery -
Then use a sewing pin(needle) to pierce top wire on TPS, turn key on/engine off, it should have 5 volts, 4.9-5.1 is OK.
Then move the black probe to the engine as the ground and test again to make sure ground is OK.


Computer wiring pins diagram here: http://www.auto-diagnostics.info/ford_eec_iv

Pin 26 is the 5v reference voltage sent out to the sensors, inside the computer is a 5v power supply that takes the 12volts from truck power and lowers it to 5volts

One other thing I would do is to pull out the computer and then open the top and look at the circuit board, it should look like the one on the image above.
If there are blacked areas then the capacitors have leaked and you may need to source a new computer

 

[Mike205]

That is another thing I forgot to post was the computer is brand new. I thought the first time I replaced it maybe it was bad so I warranties it out and no changes.

The truck at a stop light will load up and once you drive off it stumbles couple times then want have a issue out of it.

 

[RonD]

Pull a couple of spark plugs and look at the tips, blackish means running Richer than it needs too.
The sensor issues would cause that so check for the 5volts, the 5volt wire is just spliced at several points to be shared with all the sensors, a corroded or shorted connection/splice would cause problems in all those sensors.


Also on the fuel rail there will be a Fuel Pressure Regulator(FPR), it will have a fuel line(return) and a vacuum line attached, remove the vacuum line and check it for fuel or fuel smell, if fuel is found in this line then replace FPR

 

[Mike205]

Will try this afternoon

The fpr is brand new and no fuel smell. Already checked that.

 

[Mike205]

Tps seems to only be getting 3 volts

 

[Mike205]

All sensors are getting same voltage

 

[Mike205]

Can anybody tell me what is going on with this thing

Sent from my SM-N900P using Tapatalk

 

[Terry]

I would swap the relays and check voltage. The two relays are the same. Check the input voltage from the relay to the ecu. Make sure your grounds are good.

Sent from my SAMSUNG-SM-G920A using Tapatalk

 

[Mike205]

How can I test this computer. I mean getting 3 volts coming out now and 3 volts going to sensors.

Sent from my SM-N900P using Tapatalk

 

[Terry]

Did you check the input power? Did you sawp relays

Sent from my SAMSUNG-SM-G920A using Tapatalk

 

[Terry]

I have a 86 I am about ready to call pick and pull and junk it. I have pulled the sensors and stuff. If you start narrowing down the problem, I can send you the part if I still have it. You pay shipping
I would meter the input power. If is 3 volts from the relay then check the input voltage to the relay.

Sent from my SAMSUNG-SM-G920A using Tapatalk

 

[Mike205]

I'm not doing the work a guy I know is. He said voltage coming out of computer to sensors are 3 volts

Sent from my SM-N900P using Tapatalk

 

[Terry]

Have him check what I explained.

Sent from my SAMSUNG-SM-G920A using Tapatalk

 

[Mike205]

12 volts coming into relay 12 volts coming out

Sent from my SM-N900P using Tapatalk