ot/ford bronco

1995 Ford Bronco

It will be running and when you put in reverse most times it dies, will restart most times on first try. Some times takes several times b4 starting. Any Ideas what the problem is? To make this tractor related I did drive it to plug the tractor in to feed the cows. Thanks

(quoted from post at 15:17:54 01/10/16) 1995 Ford Bronco

It will be running and when you put in reverse most times it dies, will restart most times on first try. Some times takes several times b4 starting. Any Ideas what the problem is? To make this tractor related I did drive it to plug the tractor in to feed the cows. Thanks

Click to expand...

Full sized? If so I'd guess the air idle bypass motor. Right up on top just to the rear of the throttle body. 1 plugin and 2 bolts, IIRC 10MM.

It opens and closes to adjust the idle and keep it steady.

Rick

Right off the top of my head, I would also suspect the idle speed control - best way to check it is when the engine is running, unplug it and see what the engine does. If it makes no change, you MAY have found the problem. If it changes the RPM, it is working OK.
In the past, I have seen the PCM fail in that circuit on a Ford product. That does remain a possib8ility, although a rare one.
Other things I have found are wiring harness rubbed through exposing (and grounding) wiring and the little bit that the engine moves when you put it into reverse could ground an exposed wire. Also, a throttle body that was cleaned will cause problems. Starting around 1992, Ford came out with a throttle body that is not supposed to be cleaned - ever. It was re-engineered to replace the slight throttle opening for the hard stop with a calibrated hole in the throttle plate. This made it immune to the usual sludge buildup that was common on older fuel injection setups.

Get some throttle body cleaner, take the inlet off the trottle body a gentle but thoroughly clean all the black crude from throttle plate and throat. Its a very easy inexpensive first do in trying to remedy the problem. I've seen that take care of your problem many times.

I would suspect IAC , dirty throttle body also , but if you have an E4OD trans it could be a trans problem , seems like there was a problem with internal leak applying the lock up converter when put in reverse back in that time frame if my memory is working correctly . Might be worth checking into if other things don't fix it.

I have to address the dirty throttle body suggestion.

Ford introduced a new design throttle body around 1992. There was a TSB regarding cleaning throttle bodies. The re-designed throttle bodies have a sticker on them that is usually found under the air intake duct where it attaches to the throttle body warning to not clean it.

My personal experience: I had a 1993 Taurus that I bought used. It had a tendency to race up for no reason. Had to turn off the engine and restart it to get it back to a normal speed. Other times, it would stall out for no apparent reason. Apparently, the throttle body had been cleaned before I owned it. I ended up replacing the throttle body. After that, it ran perfectly. I drove it for several years after and had no further problems.

Also had a friend come to me with a 1995 Windstar that would stall and not idle right. This one turned out to be the PCM. Only time I ever saw that.

My career spanned about 25 years or so working in Ford dealers as a class A service tech. I have been to MANY manufacturer's training schools. If I only learned ONE THING in those schools, it is that we are NOT smarter than the people that designed and built these vehicles.

So, I strongly recommend that you do NOT clean the throttle body based on what I have just told you. However, it is your truck, and you are free to do whatever you want with it. I only try to advise what I know to be proper procedure as far as servicing Ford vehicles.

My brother was head wrench at the local food dealer for 20 years, was well respected at ford tech school and a bit of a maverick where ford was concerned at times. Now 25+ years with his own shop and nearly a dozen employees. His reputation has vehicles showing up at his business from surronding counties. I was having simular trouble and his advice before he would look at it for me was to clean the throttle body, his comment was that Ford says no but he has NEVER had a throttle body failure due to cleaning the throat and plate. It fixed my 1995 aerostar and later was the fix to my 1997 Thunderbird. Now I have 40+ years tech in agriculture so I not a newbie around equipment. November found my wife and I at our son's in Germany and he has had this ongoing problem with his 2005 Ford C-Max, the Ford dealer was at a loss and wanted to replace sensors what have you. The car never threw a code. He ask if I would look at his car as it was so bad his wife could nolonger drive, idle problems shut-offs and steep streets with a manual were unbearable. I cleaned his very filthy throttle body and the car has run perfect since. A cleaning will obviously not come close to fixing all electronically controlled engines but, on rough idle issues that is always the first place I look especially if there is no trouble codes.

The "do not clean" throttle bodies used a special coating on the throttle plates, probably teflon or something similar to resist carbon deposits. What they were trying to do was prevent future warranty claims. This coating or it's effectiveness did not last very long. Some of the cleaners might eat this coating off in fact cleaning the throttle body and plates too.

If the throttle body was gummed up the coating either didn't work or ended its service life, therefore clean away and have a perfectly clean throttle body. Keep in mind you should also clean the IAC and passages too, not just the throttle plates. IAC removal is easy on most vehicles so cleaning it off the car can be quick.

As it was explained to me at the Ford training school in Mt. Laurel, NJ:

The older throttle bodies were susceptible to sludge accumulation around the edges that caused turbulence and finally restriction of the air flow allowed by the slight opening of the throttle plate. This slight opening is the result of the setting of the hard stop.

The remedy was to eliminate the hard stop opening and seal the edge of the throttle plate and replace it with a calibrated orifice in the center area of the throttle plate. This opening is not as susceptible to the sludge buildup as the previous design. As such, the removal of this coating will permanently damage the throttle body requiring replacement.

Apparently, you are smarter than a 50 million dollar engineering department. So be it. I said my piece and now choose not to continue the argument any further. Do as you like.

So, just because ford claims to have remedied the problem means the problem has been resolved? I am not claiming by any means to be smarter than Frod, fords claims and reality many times are two different things. Ford claimed, at one of the service schools my brother attended, that there would be no more trans or engine repairs in the future, that dealer techs would only be servicing brakes, tires, small items. You are very naive if, you for one second, believe that any company's claims and reality are always the same. There are techs that only can functions "by the books" and then the real techs that truly address the problems. Now for the record, I, have done what was recommended by my brother, concerning this issue. Obviously you are more successful than he! You have have a far better track record than he? So, you have your own independent auto repair business of about 12 employees, with yet another building addition because you cant keep up with demand?