93 Bronco Stalls While Driving, NOT fun!

[Katie1978]

My truck has this recent issue. It's my main vehicle and I tend to do all work myself, but I need help narrowing this one down. It's taken to stalling while running. I'll be driving (today on the highway) and it'll just die. I still have power to my radio and such, but the power steering goes, the brakes go....

Then after a minute or two, it starts just fine. I'm thinking a fuel pump issue, but I can hear it start up just fine.

Any ideas out there!

Katie

 

[BroncoJoe19]

Hi Katie,

The first thing I would do is pull diagnostic codes from your onboard computer.

Here is the introduction I wrote to an instructional piece of how to do it.

All you need is a four inch piece of wire, and the ability to count to ten.

Introduction:

Your engine and transmission are computer controlled.

The computer uses sensors to tell it a number of different things and it controls actuators that push or pull mechanical levers (kinda). If one or more sensors aren't working properly, the computer goes "blind" and doesn't know what to do. If the computer can "see" but one of the actuators is broken and therefore can't follow the commands of the computer; the engine won't run correctly. The computer is preprogrammed with set values for each of its sensors, and each of its actuators. It will run a self check of all systems, like the space shuttle; it will compare its set value(s) to the value(s) it recieves from its sensors, and actuators. If any sensor or acutator is out of the "normal" range the computer will generate a "code." It will generate some codes on the fly, and others will be stored while you are driving. There is a simple method to "pull codes" out of the computer for one to use for diagnostic purposes. The ability to "pull codes" sets mechanics apart from being a troubleshooter or just a parts changer.

Fortunately all it takes to "pull" codes (find out what sensors or actuators are not working) is one piece of wire, a pencil and paper, and the ability to count to ten.

http://broncozone.com/forums/index.php?sho...amp;#entry74581

 

[Katie1978]

/emoticons/[email protected] 2x" width="20" height="20" /> Thanks, I will do that tomorrow after work and let you know what the codes are. I'm sure I'll look them up in my guide first /emoticons/[email protected] 2x" width="20" height="20" />

Hi Katie,The first thing I would do is pull diagnostic codes from your onboard computer.

Here is the introduction I wrote to an instructional piece of how to do it.

All you need is a four inch piece of wire, and the ability to count to ten.

Introduction:

Your engine and transmission are computer controlled.

The computer uses sensors to tell it a number of different things and it controls actuators that push or pull mechanical levers (kinda). If one or more sensors aren't working properly, the computer goes "blind" and doesn't know what to do. If the computer can "see" but one of the actuators is broken and therefore can't follow the commands of the computer; the engine won't run correctly. The computer is preprogrammed with set values for each of its sensors, and each of its actuators. It will run a self check of all systems, like the space shuttle; it will compare its set value(s) to the value(s) it recieves from its sensors, and actuators. If any sensor or acutator is out of the "normal" range the computer will generate a "code." It will generate some codes on the fly, and others will be stored while you are driving. There is a simple method to "pull codes" out of the computer for one to use for diagnostic purposes. The ability to "pull codes" sets mechanics apart from being a troubleshooter or just a parts changer.

Fortunately all it takes to "pull" codes (find out what sensors or actuators are not working) is one piece of wire, a pencil and paper, and the ability to count to ten.

http://broncozone.com/forums/index.php?sho...amp;#entry74581

 

[BroncoJoe19]

/emoticons/[email protected] 2x" width="20" height="20" /> Thanks, I will do that tomorrow after work and let you know what the codes are. I'm sure I'll look them up in my guide first /emoticons/[email protected] 2x" width="20" height="20" />

That's great! If there aren't too many codes, please post their numbers, and the meanings, that'll help us to help you trouble shoot it.

 

[Katie1978]

OK, so it took a few tries, but I figured out how to count it, so I hope...

The first test showed a 33, 13 and then a 3. I counted it four times and has someone else count, and we got the same. Then, the second test just flashed a 33....

A "33" is EGR Valve opening not detected, 13 is under IAC and says cannot control low idle check speed during self-test. I don't believe I had any continuous codes, as I waited and nothing flashed after the last set of codes. The 33 appeared in both the KOEO and Engine Running tests..

I think I got this down, in not, tell me what I am missing. Now, would this cause my truck to stall out while running?

Katie

,

That's great! If there aren't too many codesplease post their numbers, and the meanings, that'll help us to help you trouble shoot it.

 

[Katie1978]

And, thanks to all who helped...

 

[BroncoJoe19]

Hi Katie,

I think you'll need someone better than me to help you with this.

The "3" that you got may have been a 111 which is a pass code.

You may want to pull your IAC, and make sure it is clean. Also be sure to check for vacuum leaks.

THere is also a EGR Valve position sensor by the EGR valve EVP that you may want to look into checking.

www.fordfuelinjection.com has some helpful info on both, and I'd bet miesk5's site

has lots of good info for you http://www.broncolinks.com

Here's the EVP stuff

http://www.broncolinks.com/index.php?index=414

I don't think that the EGR or IAC would cause it to stall while running at highway speeds, but while you are at it, they should be addressed.

 

[BroncoJoe19]

Katie,

I just realized that I don't know what year truck you have, nor what engine or ignition system. Is it carbed or EFI?

Goto mycontrols, then edit your signature file with the pertenent info.

joe

Edit: I just noticed that you included that it is a '93 in your subject heading.

 

[miesk5]

yo!

13 ®: PCM could not lower idle speed below normal idle during KOER low rpm idle check. Suspect Idle Air Bypass valve

Idle Air Bypass (IAB) Overview & Testing by Ryan M

Cleaning pics in a 93 5.8 Source: by Bobby

The IAC is usually a cylindrical unit attached to the upper intake manifold. This unit electrically controlled by the computer, and allows air to flow into the intake at idle, bypassing the throttle plate. The extra air is accompanied by extra fuel to bring the idle up to proper speed, and when cold, allows a high idle condition. These units may become dirty, and need cleaning. Many idle and stalling issues tend to be blamed on these units. Cleaning is achieved by removing the electrical connector, and two screws holding it on. Once off of the vehicle, clean with throttle body cleaner (or a good carburetor cleaner). Continue cleaning until unit is clean, like new; reinstall unit. This is also a good time to clean the intake, and EGR ports (if applicable).

Testing may be achieved by bringing the engine to operating temperature, noting the idle speed (should be within spec). Unplug the unit

 

[BroncoJoe19]

Miesk5,

Welcome back!!! /emoticons/[email protected] 2x" width="20" height="20" />

 

[Katie1978]

I'm 99.9% sure it's and EFI......

It's a 93, with a 302. I love this truck. I'm not ready to send it to it's grave!!

I checked the EGR valve and it looks like it's seen better days! It's rusty and still bears the Ford logo...time for a new one. As for the IAC, I had to replace that one about a year ago. Can the new one really be shot by now??

It does have a rough idle, so I bet these two are my issue. When it stalled on the highway, I wasn't accelerating, so the RPM's could have gone down enough to stall and if these valves are the true issue at hand, that explains it.

Thanks all. I'm going to buy a new EGR valve and look at the IAC sensor this weekend. I'll let you know how it turns out.

Katie

Katie,I just realized that I don't know what year truck you have, nor what engine or ignition system. Is it carbed or EFI?

Goto mycontrols, then edit your signature file with the pertenent info.

joe

Edit: I just noticed that you included that it is a '93 in your subject heading.

 

[BroncoJoe19]

Katie,

You might want to just try cleaning your IAC.

Most people underestimate the need for a tight vacuum system on these computer controlled engines.

You might want to take a look at the connections (both electrical and vacuum) to your MAP sensor (assumming that your truck has one) it is mounted high on the passenger side firewall with a vacuum hose connected.

Checking for vacuum leaks.

Some of the sensors and some of the actuators either read the amount of vacuum, or use vacuum to move controls, therefore it is important to the proper functioning of the engine that your vacuum system is fully intact. Otherwise one may get codes falsely indicating that there is a problem with a controller/actuator, or a sensor when in reality it is caused by a lack of vacuum.

Look at your rubber vacuum hoses (they are about 1/4 - 3/8 inches in diameter, if they are dry rotted or cracked, replace them. IF they slip on/off of their connectors too easily, they may have stretched out a little bit, cut the ends off, and put them back on.

You may listen for a leak. Sometimes using a cut off piece of garden hose is a good aid to listen with. Sometimes a cardboard tube (like from gift wrapping paper) is helpful. Just remember that whenever you stick your head inside a running engine compartment, that you are not wearing any loose clothing or jewelry that can get caught.

Another suggestion is to use a spray can of carb cleaner and spray around the bottom of the intake manifold, and the base of the throttle body assembly. IF there is a leak, you should hear a change in your engine.

 

[Katie1978]

Hi Again!

I cleaned the IAC, replaced the EGR and some hoses and I'm still having issues...

It stalls at low idles, but not on a constant basis. Sometimes it's fine, other times it's not. It cannot seem to keep the RPM's up enough to not stall. Is there anything else I can check into? I've also repalced the distributor cap, but nothing changed. I heard there is some sort of arm on the engine that can cause this to happen. Or should I just ditch the truck!!

Yesterday, in rush hour traffic, it stalled nine times. Ugh!

Katie

 

[BroncoJoe19]

Hi Again!
I cleaned the IAC, replaced the EGR and some hoses and I'm still having issues...

It stalls at low idles, but not on a constant basis. Sometimes it's fine, other times it's not. It cannot seem to keep the RPM's up enough to not stall. Is there anything else I can check into? I've also repalced the distributor cap, but nothing changed. I heard there is some sort of arm on the engine that can cause this to happen. Or should I just ditch the truck!!

Yesterday, in rush hour traffic, it stalled nine times. Ugh!

Katie

Is your air filter clean?

Could be your MAP sensor.

Try pulling codes again.

The rule is that one should have a tight vacuum system PRIOR to pulling codes. now that you tightened up your vacuum system, pull codes again, this way you are likely to get a more accurate reading.

When was the last time you checked the plugs? Is it idleing rough? does it have a miss?

Just throwing thoughts out there.

joe

 

[illinoisbronco]

mt truck had this problem a couple of days ago after i addressed a couple of timing issues and come to find out, i checked the fuel pump. which is easy to find, whatever ****** owned the truck before me had stripped a couple of spots on the hot and ground wires that power the fuel pump and crudely twisted some wires onto them for something. it was grounding out on the frame. how freaking safe is that? if i knew who owned my car before me id drive to their house and slap them in the back of the head.

but, i would check for a sound connedtion on the high pressure pump before the filter. very easy to find.

 

[Katie1978]

I pulled the codes again and got the same ones. Do I need to reset the computer?

It idles really rough, I don't think it's missing though. I'm going to go check the air filter now. I threw in some injector cleaner and drove about 30 miels. It accelerates smoother, but it still stalls. This one is a real pain in the ass! I'm hoping I can fix it here, instead of having it shipped off...

Katie

Is your air filter clean?Could be your MAP sensor.

Try pulling codes again.

The rule is that one should have a tight vacuum system PRIOR to pulling codes. now that you tightened up your vacuum system, pull codes again, this way you are likely to get a more accurate reading.

When was the last time you checked the plugs? Is it idleing rough? does it have a miss?

Just throwing thoughts out there.

joe

 

[illinoisbronco]

I pulled the codes again and got the same ones. Do I need to reset the computer?
It idles really rough, I don't think it's missing though. I'm going to go check the air filter now. I threw in some injector cleaner and drove about 30 miels. It accelerates smoother, but it still stalls. This one is a real pain in the ass! I'm hoping I can fix it here, instead of having it shipped off...

Katie

disconnect the negative battery lead for about 2 minutes and that'll reset any stored or confusing codes to what is accurate

 

[Katie1978]

So, after three hours of working and nearly another $100, I still have a POS that still stalls. I'm now really irritated. This is my only vehicle, and it's getting old stalling out in the rush hour traffic I must drive through.

Here's what's been done:

New IAC sensor

New EGR Valve

New Fuel Fliter

New Air Filter

New Plugs, Wires, Cap and Rotor

Replaced pressure tubing

Added some fuel injector cleaner stuff

Any ideas before I drive it off a cliff?

Katie :angry:

 

[BroncoJoe19]

Looking back.. one of your codes was A "33" is EGR Valve opening not detected.

Now taking that literally, it doesn't mean the the vale is not opening, it means that the EGR Valve Position Sensor (EVP)did not send a signal that it opened.

WHat does that mean?

1, the EGR valve is dirty and sticky clogged or broken. You replaced it. and code 33 remains

2. The connections to the EVP are dirty, corroded, or broken.... check the connections... clean and tight? Check for voltages, as suggested here http://fordfuelinjection.com/index.php?p=35

If that's not clear, we'll have to get more info for you.

3. the EVP is faulty