Good morning. I recently bought a 1993 Ranger Splash w/3.0. I bought a Innova Ford code reader, installed battery's and connected to the ports under the hood. I haven't done Ford vehicles in a while, so I read the manual (most of it) and it wont even link to the truck. I'm thinking the signal wire from the computer, but not sure how to repair this. Any help would be appreciated.

 

Welcome to FTE.
No replies yet, so will see if I can get things started. Do you have another OBD-1 diagnostics Ford you, or a family member, neighbor, or friend has, that you could try the Innova on to see if it has a problem??? Might be helpful to know what model # the Innova is.
Does the vehicle CEL light up for its self-check Every Time when starting the engine???
You could wire up one of these OBD-1 diagnostics "self check" scenarios https://www.troublecodes.net/ford/, to see if the vehicles wiring or ECM has a problem, or to scan for trouble codes as the rig has the dash CEL, or your rig 12 volt light source blink, the analog meter wave, or a 12 volt buzzer to Sound the codes, or to just check to see if the vehicle self diagnostics system is functional
Some beginning thoughts for consideration, let us know what you find...

 

I purchased a Innova 3145 because the truck doesn't run very well. There is no CEL on, nor does any lights flash. The only light on is the ABS which I'll leave for another day. It appears that everything on the dash works as designed. I think. Looks to me like the only power to the reader is it's own battery power. I am going out to check the connections to the reader. I'll let you know what I find. Thank you.

 

That solved the issue. The reader works fine, but now I need to solve the 136 code. Hmm. I am going to start with searching for vacuum leaks before anything else.

 

The vehicle dash Check Engine Light should come on when we Pause when turning the ignition switch to On, before going to start, to crank the engine. If not burned out, a number of the dash warning lights will then come on for a couple of seconds for their self-test, so we know the lamp isn't burned out, or a system isn't getting power for some reason. The link self-test hook-up's gives us more ways to see if the diagnostic system is getting power, in case the CEL is burned out. So, if one of those wiring set-ups indicate trouble codes are being outputted, we know the vehicle diagnostic system is ok, so the Innova, or its wiring has a problem & goes to the top of the suspect list. So make sure the vehicle diagnostics are working & if so, since the Innova is new, make sure all of its connector pins & sockets are in place, not pushed back or bent, or try it on another older Ford to see if it'll work.

 

Wooops, looks like you found the problem & our messages crossed each-other coming & going. Keep us posted on how the trouble-shoot goes & good idea to First look for trouble code clues.

 

The code P0136 is for the Passenger side cylinder bank-1, After cat converter O2 sensor Circuit Malfunction. So look for a wiring or electrical connector problem. More thoughts for pondering, let us know what you find..

 

OK. I just crawled under the passenger side of the truck and found there is no cat. converter. We live in an area where there is no emission testing, so apparently the previous owners removed it and welded in a straight pipe. I also can't find any videos or posts showing a downstream 02 sensor. Just the 2 upstream. With that, shouldn't the truck run fine without the converter? It may not pass inspection yet, but would "not having the converter" cause the engine to run terrible under a load? And Thank You for your assistance.

 

Ok that's good feedback, so lets think about this some more. The after cat O2 sensors job is to monitor how well the cat converter is performing, not to help run the engine, so you may want to wonder Why the cat converter was removed??? Contact the previous owner to determine if they did it & if so why. If it was removed because it was overheated & the matrix melted down inside causing excessive exhaust back-pressure from a overly rich fuel trim, maybe you'd have a clue as to why it's not running to your liking. Like a upstream fuel, spark, or engine head, or gasket problem???
If it was done to improve the 3Slows get up & go, you'd want to find out what else may have been messed with, so you can begin to get an idea how much the resurrection may cost to get it running to your not clear "better" liking. Lots of unknowns that need answering.

 

Ok, so here is where I am at this point. I tested the 02 sensors. One had 3 ohms and the other was at 4.1. I was told between 5 and 10 ohms was what the ohms needed to be. I replace both of them. I put the fuel pump pressure gauge on it and it would only go to approx. 35 psi after turning the key several times. It would lose pressure just as fast. I replaced that to. I'm still getting the 136 code. I did the cylinder test and yesterday it showed #2 and #6 we weak. I put fresh gas and some cleaner in the tank and put a few miles on it. Now only #6 is weak. And still a 136 code. I put my stethoscope against the injectors that I could get to and they all click to include #6. Could that injector be plugged not letting gas through? Thanks in advance.

 

Fuel pressure @ 35 psi was ok, range is, at idle with FPR vacuum line Attached 25-35 psi, with FPR vacuum line Detached & plugged, 35-45 psi. Fuel pressure Should Not rapidly drop off after engine shut-down. If it does, suspect the fuel pump anti-drain-back valve, FPR diaphragm leak, or dirty fuel injector/s with a runny nose. So what did you replace???

What were you testing on the O2 sensors, the heater circuit??? Did you have a trouble code that caused you to put the O2 sensors on the suspect list???
What did the new ones measure???

What cylinder test did you perform, a compression, or cylinder balance test???

On the P0136 code, have you done any circuit trouble-shooting, or replaced the removed cat converter, so the after cat O2 sensor is measuring how the converter is doing, rather than measuring how well cylinder banks 1 & 2 are doing controlling their air / fuel ratio.
If the after cat O2 sensor is just monitoring what the straight pipe thats replaced the converter, it doesn't have a cat converter steady output to monitor, so the varying O2 levels of the 2 cylinder banks non treated exhaust are likely driving the after cat O2 sensor crazy, when it compares its Expected algorithm numbers to the wild swings of cyl banks 1 & 2 untreated exhaust stream, so its not likely the 136 is going away until it has a functional cat converter in front of it to measure, as designed.

 

I'm probably in the wrong section. Thank you for the help. The only code I get from the computer is 136 R HEGO (HO2S) sensor fault, always lean. I have no after cat 02 sensor. The checked the heater (white wires). 3-4 ohms. I heated up the sensor and checked voltage. .0.1 volt for both. I read that the ohms resistance should be 5-10 ohms. Since mine were low, I changed them. I didn't think to check the levels of the new sensors. Fuel pump will not hold pressure. Since it was out, I went ahead and replaced, along with the filter. I just pulled the injectors and I have 1 that isn't working at all. No click when power is added. I found a site that showed a tree shade way of testing the spray from the injectors. The other 5 injectors work but hard to tell how well. So I have a set ordered along with a new regulator. I tested the MAF and its good. The TPS is working as well. The check engine light does not come on, KOER test has the 136 code. I did the Cylinder Balance Test and at first, #2 and #6 cylinders were at issue. After a bit of running, #2 picked up, but 6 still had issues. The faulty injector did come from the left bank.

 

Ok, Good feed-back, you've been Really busy trouble-shooting / repairing this puppy. Good idea to have replaced the fuel filter, so when the fuel system resurrection is finished you know what baseline you have for it.

On the injectors replacement, before installing the new ones, be sure to measure Each injectors ohms resistance, it should be between 12-16 ohms & All should be Closely matched for Resistance, as this is a tuned electrical circuit.

On the cylinder balance test, the scan-tool disables each fuel injectors ECM electrical ground switching & measures the amount of engine RPM drop, so that test is a good one that can help focus a trouble shoot.

 

I will do that. Thanks for the assist. I will post the results when its done. Probably Monday.

 

Ok. So I received the new injectors. The ohms resistance is 14.3 for all 6. Installed them yesterday. Buttoned the thing up. As soon as I started it up, it began knocking. All tools, nuts and bolts accounted for, and I covered the intake so I don't think anything dropped down there. It sure sounds like a rod, but I don't see how that could be. There was absolutely no engine noises prior to doing the injectors. I am going to tear it back down to the injectors and start examining what's going on.