I have a 1991 Ford Ranger that has recently had an engine change. The engine was ''professionally'' exchanged by two teenage boys - so it's a wonder that it runs at all. Anyway, since the engine was changed, the truck has a severe loss of power. It idles fine, but when shifted into gear it feels like it is starving for power as you accelerate. The motor doesn't miss, it just feels like your driving up-hill, in the wind and in four feet of water.
I've checked the vacuum lines and secured any that were not tight.
I scanned it KOEO and got codes 14, 41 and 96.
I scanned it KOER and got codes 41 and 13.
Any ideas of what I can do to get this turd running strong?
Light blue/red is for "PCM sens" it should be less then 2 ohms. and tan/light blue is for "PCM return" it should be less then 2 ohms
Clean the MAF sensor with Throttle Body Cleaner. This cleaner is intended to be used on Fuel Injection intake manifolds and parts.
To clean the sensor:
1) Disconnect the MAF electrical plug
2) Remove the two security torx screws (you can get the correct torx bit at the parts store with the hollow center)
3) Gently pull the sensor out of the air intake
4) Spray the heck out of the two small resistors with the cleaner with the spary tube attached to the can (they should appear a shiny silver color all over)
WARNING: DO NOT CLEAN THE RESISTORS WITH A COTTON SWAB OR TOUCH
THEM AT ALL. They're very fragile and can break.
5) Reinstall the sensor
Fuel pump? was the fuel filter changed out? could also be a fuel pressure regulator.
Ignition Timing and Firing order should be looked over as well!!!
Check also the MAF sensor, and the wirings to MAF sensor, if you get error 66 there may be no voltage to MAF sensor.
If that year had a coil pack... it sounds like that is the issue
code
14
Ignition signal.
41
Throttle Position Sensor signal
13
Knock Control CPU (ECM).
looking at those codes it sounds like the hard working "professionals" forgot to hook some things up.... was the engine swap from the same year vehicle ?
Robert
just pull one lead off at time and note any change in how the motor runs... replace it... pull another off. .. if you find a dead cyclinder (or two) replace the coil pack
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Plugged air or fuel filter?
Plugged catalytic converter?
You may have a faulty coil. Check mass air flow sensor .
also sounds link Sounds like a bad clutch or pressure plate .
this all needs to bne checked.
The engine needs proper resetting as its not properly fitted.also check out the connections.
It seems there is some fault in placing the new engine.
contact to the repair shop.
U say u have 40 PSI fuel pressure, what happens when u quickly throttle the engine, the pressure should go to about 46 PSI, it should never drop, if it does drop then you either need a new fuel filter or pump or both, if you have a MAP sensor try cleaning the inside of the sensor with MAF cleaner made by CRC chemicals, avail at any auto parts store like Kragen, NAPA etc.
One other question have u checked to see if u have excessive exhaust system back pressure, this will play Havoc.
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Engine is from the same year. TPS is hooked up. Also, I checked fuel pressure at the injectors which read steady at 40psi.
Fuel pressure is steady 40 psi with engine running. Key on engine off is 12 psi - this doesn't seem right?!?!?!?
My mistake. I had let the pressure off of the system. When I cycled the key a few times, the pressure climbed to 40 psi with key on and engine off. It maintains that under load as well.
Throttle Position Sensor has been ohm tested and seems ok.
What is the best method for testing the coil pack?
Replaced the coil pack and spark plugs. Did not fix the issue.
Ran new KOER test, got the following codes:
13 - Cannot Control RPM, Low RPM Check
41 - Lack of H02S Switch, Lean Bank 1
77 - Insufficient RPM Change Dynamic Test
I also did a datastream. All looks ok other than the O2 sensor is reading "rich" rather than bouncing back and forth from rich to lean as it should.
I do not have a check engine light as I would expect with a faulty O2 sensor.
fuel pump tests good and back pressure tests good as well. MAF Sensor was removed and cleaned.
Based on the O2 sensor showing a constant rich reading during testing, I pulled it and tested it. It tested poorly. So, I replaced it.
The truck still runs horrible.
Scanned it again. Now I get these codes:
KOEO:
66 - MAF Circuit Lower Than Minimum Voltage
95 - Fuel Pump Circuit Open PCM to Motor Ground
KOER:
Codes 41, 13 and 77.
Although it was fine, I pulled the MAF and cleaned it. I also checked voltage at the MAF plug. The ground was solid, the 12 volt power supply was great. The remaining two wires I'm unsure of. One (tan/blue?) read approximately 6 volts. The other (light blue/red) had no voltage.
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