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ronmar1

87 Bronco 2 surging, missing, and running fine, sometimes!

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Help needed!

 

I can start up my 87 Bronco 2 XLT, with a 2.9 fuel injected V6 and it runs great, smooth and steady. That is, till the temperature of the engine warms up 5 or 6 miles maybe. Then it will start surging under load and missing like crazy. Now while driving and staying in drive, I can turn off the switch and immediately turn it back on and everything is fine, for another 2 to 3 miles. Then the symptoms start again. Sometimes I can press down the accellerator till it drops a gear and it will catch and run smoothly again, momentarily, then back to the surging again. When it's cruising straight and level, at a steady throttle and it starts missing you can feel the surge kind of come and fade like a cycle up and down. When this surging happens it shows signs of flooding. Black smoke from exhaust. It's like something that resets after a re-start but then goes haywire after a couple, or 3 minutes.

 

Checked my codes and got an 18 and 33. Egr not opening and spout connection.

 

Here's what I have done. Replaced Ignition Module, replaced distributor pick up module, and cleaned connections(no change). Replaced EGR vacumn switch. Checked and replaced most vacumn hoses and connections. Cleaned and checked EGR, (no change). Replaced MAP (no change) Replaced throttle position sensor (no change). Replaced air by-pass assembly (no change). Replaced engine temperature sensor, (no change). Checked fuel pressure 32 lbs and constant, running. Replaced fuel filter (no change). Replaced ECM (no Change). Cleaned throttle body (no change). Ran 2 cans of injector cleaner through it (no change). Checked vacuum and it shows 20lbs at idle. Vacuum drops to 10 to 12 during the episodes.

 

Well as you can see I have tied up a tidy sum throwing parts at this thing and (no change).

 

Sure hope somebody has an answer here. This must be a common problem. Not only do I have this problem with this B2, but I have a second 87 B2 that I parked last year and it was doing the exact same thing!

 

How about it guys, jump in here and tell me what I'm missing! All ideas appreciated.

 

Thanks for any help.

Ron

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When I did my TPS I had to pull my throttle body (because it is underneath it!). I gave it a good cleaning. I think one of the vacuum ports may have been clogged.

 

IF that went to the EGR... IF that is the vacuum that is used to open the EGR, and it is clogged, one could get a EGR not opening code.

 

Could a flaky fuel pressure regulator do this?

 

Another thought, the O2 sensors should be changed depending upon year of manufacture between every 30,000 and 100,000 miles.

 

Here are some tips on looking for a vacuum leak.

You also have some vacuum controls under the dash for the heating ducts, so listen there also.

 

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.

Keep a fire extinguisher handy, or use water instead of carb cleaner (it works, but not as well.) Be aware that if you use water and the wires get wet and it runs worse... your wires may be bad, and the water is allowing them to arc instead of jump the gap of the spark plug.

 

Another suggestion is: to take a propane torch, turn it on (but don't light it) and move it over the vacuum hoses and connections. The engine RPM's will increase if there is a leak and the propane gets sucked in.

 

Don't forget to check the PCV valve, hose and grommet !

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When I did my TPS I had to pull my throttle body (because it is underneath it!). I gave it a good cleaning. I think one of the vacuum ports may have been clogged.

 

IF that went to the EGR... IF that is the vacuum that is used to open the EGR, and it is clogged, one could get a EGR not opening code.

 

Could a flaky fuel pressure regulator do this?

 

Another thought, the O2 sensors should be changed depending upon year of manufacture between every 30,000 and 100,000 miles.

 

Here are some tips on looking for a vacuum leak.

You also have some vacuum controls under the dash for the heating ducts, so listen there also.

 

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.

Keep a fire extinguisher handy, or use water instead of carb cleaner (it works, but not as well.) Be aware that if you use water and the wires get wet and it runs worse... your wires may be bad, and the water is allowing them to arc instead of jump the gap of the spark plug.

 

Another suggestion is: to take a propane torch, turn it on (but don't light it) and move it over the vacuum hoses and connections. The engine RPM's will increase if there is a leak and the propane gets sucked in.

 

Don't forget to check the PCV valve, hose and grommet !

 

The TPS doesn't use vacuum. it's electric and it is accuated by the Throttle body butterfly shaft.

 

I have eliminated the EGR code 33. I replaced the EGR vacuum selinoid and all the vacuum hoses and tubes that connect the selinoid to the EGR valve. Egr valve was also removed abd cleaned. All other Vacuum hoses and connections were checked with WD40 and no leaks were found. I checked the fuel pressure it holds a constant 32lbs when the engine is running. I also checked the intake with WD40. WD40 will cause a change in in engine RPMs and is not quite as dangerious as some other methods. An intake would more than likely be constant and not come and go and seem to cycle in and out. Remember too that when the engine acts up, I can cut the switch off and immediately back on and it will run great for anpther 2 to 4 miles. Leads me to think more in the terms of something controlled by the ECM, that is activted upon warm up, maybe.

 

I have a constant 20 lbs of vacuum when engine is running normal. If I had a vacuum leak you would think the vacuum would be less or at least irractic.

 

It is also seems more like a bad sensor since it runs great till the engine reaches normal operating temperature the it acts up. When engine is cold it runs great!

 

Thanks for the reply! Still looking for a cause.

Ron

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Did you correct the SPOUT Circuit Open problem?

 

DId you change your air filter?

 

Did you pull the neg bat cable to clear the computers fuel trim memory after you changed anything related to fuel? MAP EGR etc.?

 

Does your vacuum reserve canister hold vacuum? I recall ShadowD's rotted out.

 

IF it is running rich, check for an exhaust leak before the O2 Sensor.

I hate to throw parts at this, but out of frustration I'd change the O2 sensor, it is probably due anyway. IT is also one of the sensors that is ignored until the engine warms up.

 

IF you start it and let it sit and idle in the driveway will it surge when it warms up, or do you have to take it for a drive first?

I'm thinking that you have two fuel pumps and one may be getting flaky. I think (but I do not know what pressure an '87 B2 should have) that 32 psi is on the low side of normal. Check electrical connections clean and tight, Perhaps disconenct connectors, and spray them with electronic contact cleaner, and then apply a dab of dielectric grease.

 

Check your grounds. Other than the obvious battery connections, but the two on each side of the radiator support, and if you find one under the dash driver's side. Also the one near the PCM.

Edited by BroncoJoe19

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In addition I am wondering... why does your vacuum drop when your problem is evidenced?

 

Perhaps if you pinch off some vacuum lines while it is running that may localize a leak.

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Did you correct the SPOUT Circuit Open problem?

 

DId you change your air filter?

 

Did you pull the neg bat cable to clear the computers fuel trim memory after you changed anything related to fuel? MAP EGR etc.?

 

Does your vacuum reserve canister hold vacuum? I recall ShadowD's rotted out.

 

IF it is running rich, check for an exhaust leak before the O2 Sensor.

I hate to throw parts at this, but out of frustration I'd change the O2 sensor, it is probably due anyway. IT is also one of the sensors that is ignored until the engine warms up.

 

IF you start it and let it sit and idle in the driveway will it surge when it warms up, or do you have to take it for a drive first?

I'm thinking that you have two fuel pumps and one may be getting flaky. I think (but I do not know what pressure an '87 B2 should have) that 32 psi is on the low side of normal. Check electrical connections clean and tight, Perhaps disconenct connectors, and spray them with electronic contact cleaner, and then apply a dab of dielectric grease.

 

Check your grounds. Other than the obvious battery connections, but the two on each side of the radiator support, and if you find one under the dash driver's side. Also the one near the PCM.

 

Air filter was changed.

 

Old codes and settings were cleared.

 

B2 will sit and idle just fine till the temp gets up to normal, then just like when driving it goes crazy when normal opperating temperature is achieved.

 

Will check grounds and fuel pumps. Hvee not installed o2 sensor yet. I figured if it was bad I should be getting and o2 sensor code?

 

All connections and wires have been checked and cleaned.

 

Grounds are good.

 

Still getting SPOUT code 13 although I have replaced hall effect sensor in the distributer and I have replaced the ignition module on the distributer. Any other causes for this?

 

Ron

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In addition I am wondering... why does your vacuum drop when your problem is evidenced?

 

Perhaps if you pinch off some vacuum lines while it is running that may localize a leak.

 

Vacuum drops because performance is greatly compromised when engine acts up. I have plugged every vacuum on this thing when problem occurs. No help though.

 

Ron

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Still getting SPOUT code 13 although I have replaced hall effect sensor in the distributer and I have replaced the ignition module on the distributer. Any other causes for this?[/b]

 

Old codes and settings were cleared.

 

B2 will sit and idle just fine till the temp gets up to normal, then just like when driving it goes crazy when normal opperating temperature is achieved.

 

Will check grounds and fuel pumps.

 

All connections and wires have been checked and cleaned.

 

Grounds are good.

 

 

Well it's not the O2 sensor. That's another new part . Just about got enough spares to build a second one now. I did brake down and call a Ford trained mechanic and he advised that I have already done everything he could suggest.

 

Is there anything that can cause a 13 SPOUT connector code other than Hall effect module and the ignition module?

 

Ron

Edited by ronmar1

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BRONCO 2 CURSE!!!!!!!

 

 

 

Well if anyone ever comes up with a resolve for this problem, and it is a common problem as I have found through this and other forums, Please let me know. It appears that the 86 and 87 Bronco 2's with a 2.9 were plagued with this problem, and as I have found no-one has ever been able to resolved the problem once it starts. I've read numerious forums and they all say the same thing. Runs great when cold, reaches normal tempertature and it starts missing and bucking like a, well for lack of a better word "BRONCO". First start it up and it runs great till it reaches normal opperating temperature and then it all starts going down hill. Black smoke, missing shaking, no power. You can cut the switch off and right back on and it will run great for a few of miles and then it happens all over again.

 

I give up. I've now parked this 87 Bronco 2 parked right beside my other 87 Bronco 2, with the same problem. Yep they both have the exact same problem and they both have all new sensors, new ECM, new vacuum lines, lots of new wireing. One has a new distributer and the other one has a rebuilt distributer.

 

Heck now this one even has a brand new, complete distributer, and oxygen sensor. Everything that I can find that could be a possiblility, has been replaced. still no resolve. From what I hear this must be the Bronco 2.9 curse!! Oh yes I failed to mention I took the plentium off and cleaned it and the intake. re-installed it with new gaskets.

 

Last ditch effort! Took it to FORD and they couldn't find the problem either. They said it could be the ECM, but that was not a gurantee. Well i didn't got that route as the ECM had already been replaced.

 

Any body want a good deal on either of my Bronco 2's, both with lots of new parts? Can't say they run too well, except when cold they nrun great, but the both look good, just setting there! I've resolved now that it is an uncureable curse!

 

WARNING!!!! Beware of the Bronco 2 curse!!

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THERE IS A GOD!!!!

 

In a last ditch, desperation attempt, I went out this week, and bought another ECM for my BII. I pulled the recently replaced ECM, and intalled the new one.

 

With a prayer and and being very carefull not to get my hopes up, too much, I got in and started the engine. Sounded fine, but it is only after warm-up that the usually missing and sputtering started. So with great antisipation I waited till the temp hand got up to normal. Hey, it still sounded good! Could it be possible? After sufficent time for warm-up had pasted, the engine was still purring. I pulled it into gear and left my drive way. 30 miles later the engine was smooth as silk, and not even a miss. A great big smile crept across my face! Could I be mistaken? Could it be true? Not wanting to be too eager to proclaim victory over the curse, I took the BII home and let her set over night. This morning I went out and cranked her up. Guess what! Smooth as silk!!!!! I drove her around for a while and not even a hesitation!

 

Moral of the story? I don't know one, but I do know that, I will not ever again feel that replacement parts should be considered to be always good. Strange that the first replacement ECM would create the same problem code and symptoms as the original one, but it did.

 

Now if my neighbors will just forgive me for creating such a disturbance, with all my joyful bliss!!!!

 

Hope this helps someone else along the way. Just glad I didn't give up and call the crusher, although I did give it some serious consideration!!!

 

Thanks for everyone's input and attemts to help on this one!

 

Ron

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Congratulations!!!! Feels good to hear another Bronco was saved from the crusher.

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Same basic problems, but w/just one 86' B2, ever since day #1. Wasn't thinking crusher (no self satisfaction in that) but did more than once grab my sledgehammer w/the intent of pulverizing the beast beyond recognition. Unfortunately, always came to my senses before my emotions got the best of me. Anyhow, thanx Ron for what I feel must certainly be the same problem. Will keep all concerned posted on the outcome...

 

Cordially, treemendous1

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2/14/16. So how about an update on the Bronco 2 curse as I believe it just got me. Have a 1987 Bronco 2 Eddie Bauer 2.9, 4x4. Purchased new off showroom floor. Approx 170,000 miles. Best car I ever owned with only the run of the mill repairs. It started spitting black soot and clear liq. water condensation out exhaust pipe about 8 months ago but since my wife came down with cancer I had no chance to ck. it out. So as of today I replaced the dist. cap, rotor, wires, spark plugs, PVC valve, O2 sensor, fuel filter & a new thermostat with no luck so took to repair shop and they put the trouble shooter to it and only found the MAP Sensor was bad and replaced it with a new NAPA sensor part which is all the smaller shops use instead of FORD parts. Still did not cure problem. Problem starts when engine is up to temp. Let it sit a while and runs good until it heats again. Only thing I did not do yet is remove new O2 sensor and put anti_ seize compound made for this purpose only on the threads only. Don't use a conventional paste as it can insulate the sensor useless. I have not removed the battery ground cable yet which they say resets the PCM and life is suppose to be good. Will do this tomorrow. Any ideas would be much appreciated. Just to let U know my wife did not make it. Kind of crazy as I bought the Bronco 2 for her as she needed 4x4 to get to work in winter as we lived at 7200 ft. Elevation in mountains of New Mexico. Seems like the Bronco went out with her. Strange.

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Yo AL,

WELCOME!

 

I am very sorry to hear about your wife, PLEASE ACCEPT MY condolences.

 

Did the shop test for diagnostic troubles codes?

If so, can you post them here?

 

Here is the code test by Ryan m.

http://web.archive.org/web/20130912170844/http://www.oldfuelinjection.com/?p=13

 

And a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19

http://broncozone.com/topic/14269-code-reader/?pid=74587&mode=threaded

 

 

 

Black Smoke: Black exhaust smoke is an indication of rich fuel condition. These are possible causes:

 

Fuel Injectors: A leaking or dripping fuel injector will cause a rich fuel condition.

 

Fuel Pressure Regulator: A stuck closed fuel pressure regulator will cause a rich fuel condition.

 

Fuel Return: A restricted fuel return line will cause a rich fuel condition.

 

check the vacuum line to the fuel pressure regulator (FPR) for gasoline (gas is indic of a bad FPR). If inconclusive to this point, put a fuel pressure gauge on the fuel rail and test fuel pressure.

 

****

 

Blue/Gray Smoke:

PCV System: A stuck closed PCV valve will cause excessive crankcase pressure resulting in blue/gray smoke.

Oil burning in the combustion chamber. Pull a few spark plugs & ck iaw Spark Plug Diagnostic Chart

http://www.gsparkplug.com/shop/spark...ult-diagnosis/

Oil Deposits Symptoms: Oily coating caused by poor oil control. Oil is leaking past worn valve guides or piston rings into the combustion chamber. Causes hard starting and misfiring.

 

Valve Seals: Leaking valve seals will cause blue/gray smoke at startup because oil leaks past the seals into the cylinder after the engine shut down.

 

Valve Guides: Excessive clearance between the valve stem and the valve guide allows oil to leak past the gap into the cylinder.

 

Piston Rings: Worn or damaged piston rings will cause blow-by resulting in blue/gray smoke.

 

Worn Cylinder Walls: Worn cylinder walls cause blow-by resulting in blue/gray smoke.

Be well,

Al

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