I have an '86 Ford Bronco II 4wd drive with an automatic Transmission. The type of transmission is an A4LD. I have recently replaced the transmission along with many sensors pretaining to emmissions. My Bronco is running great now but for some reasons it has a problem starting when the engine is cold. I did a search on autozone.com for a cold start valve and it lists this as a fuel injector. I am wondering if it does indeed have a cold start valve which I believe that it does not. Or does anyone have any suggestions on as to why I am having this particular problem. The problem that I have had in the past has been with the Bronco blowing carbon out the exhaust and burning real rich causing it not to pass emmissions but I have that issue taken care of now just don't ask me what took care of it because I replaced so many sensors along with cleaning the intake out. Any suggestions would be great.

 

No, you don't have a cold start valve. On Toyotas, VW's, and some others, the cold start valve is basically an additional injector that pumps fuel into the intake manifold when the computer tells it to. The B2s don't have them.

Have you pulled codes to see if that points you toward anything in particular?

 

What is the best way to pull the codes if you don't have a scanner. I have reset the brain due to all the work I have done on it and now it is driving better then ever but just doesn't like to start when cold for some reason. I don't believe that it is the starter itself though.

 

Check out the link in the tech info post, with a 86 you can't do the CEL thing.

 

Don't call me stupid but what is the CEL thing.

 

CEL = Check Engine Light

On the later B2s, you can pull codes using a piece a wire and counting the number of flashes on the CEL.

 

So you are saying that I can not do this on an 86 B2. What exactly does the LED light on the ECM do or dsiplay.

 

I thought you could do it on the 86s.

 

I am not sure if you can or not. You said earlier it can not be done on an 86. If you can where exactly do you connect the wiring up to.

 

You don't have a cold start valve, however your problem could be due to the air bypass valve, also known as the idle/air control valve. If you don't know or are interested in knowing what this valve does and how it works then let me know...it is pretty simple. Anyway, if the valve is not functioning properly then it can cause serious problems on cold starts. Mine is going bad and it will start up in the morning and then die right away unless I hold on the gas but after it does that a few times it will run and idle just fine.

 

As far the CEL thing goes, all I know for sure is this:
1) It works fine on my 90 B2
2) It won't work on some of the early B2s

I don't know if it will work or not on your 86. I thought I read somewhere that the CEL wasn't even present until 87 or so, but I really don't know. If you have a CEL, give it a whirl.

 

To Bronco2guy I have basically the same problem but I have already replaced the idle/air control valve. I have replaced the MAP sensor as well the EGR valve, among other sensors about the only thing that I haven't replaced would be the fuel pressure regulator. I have even taken the intake off and thoroughly cleaned all the carbon buildup in it. But I have replaced every sensor on the intake. Why don't the 86 B2's have a Mass AirFlow sensor on the air intake?

 

Use a wire and a test light, the only problem I found is that the diagonostic conectors are on the passenger side, and obviously your ignition switch is on the drivers side. It acts the same way as the CEL only its the test light that blinks the codes. The connectors I am refering to are next to the air box under that plastic cover, one looks like a half of a 2" stop sign and the other is a single wire connector. As far as the distance problem I just used a extra wire I had laying around, and then hooked the test light to the wire, that way I could turn the key on and off with out assistance.
Mine has had problems starting due to the external fuel pump, the one mounted on the frame, the connections were bad after a good cleaning and a new mounting solution it starts fine every time. The moisture in the cool morning air was my problem.
Good luck with it!

 

An exceedingly rich mixture makes me think theres a defective vacuum connection going to the Fuel Pressure Regulator on the Intake Manifold, near the rear of the engine on the Driver's side. It's probably a short combination rubber-plastic hose bent like a squared "S". If the hose is good properly connected, the regulator's internal diaphram might be ruptured, therefore requiring replacement of that regulator unit. A special tool may also be needed to disconnect the garter-spring-type high-pressure fuel line unions to do that replacement. Recoupling the unions isn't as hard as some manuals will tell you.

It sounds like you could benefit from getting yourself The Haynes Service Manual #36070 (about $20 at many auto parts stores or Amazon.com online). It would help explain things and answer most of your questions mentioned herein, M6TTM6M. It will instruct you on how to jumper your vehicle's Test Connectors to retrieve its ECC error codes, how the ECC can be manually reset, as well as how it will reset itself, once faults have been corrected.

As far as there being no Mass Airflow Sensor, I'm thinking the MAP sensor is the what is used to provide the necessary information to the ECC (EEC-IV) as to how much air exists that needs to be fed with fuel, until the EGO (exhaust gas oxygen)sensor can give it the necessary feedback data.

But, get the Haynes manual anyway. It's well worth the money! I don't know about Chilton's manuals, but I've nearly always been frustrated with theirs.

I've also got the Ford Factory Service Manuals for both the '84 and the '88, which I needed to upgrade my '84 to the '88 powerplant, using the latter as a parts vehicle. Though they provided some detailed information not presented in the Haynes, THEY don't go into the detail as to how to retrieve and decipher the Error Codes that the Haynes does. So, I use ALL three manuals to properly maintain my Bronco-II.

Let us know how it goes!