engine wont stay running

[1986bronco2]

1st off let me say hey to everyone here. im new to the site. i stumbled over while searching for a solution to my problem so i figured why not give this site a try. now for my problem. i have an 86 bronco 2. 2.9,5speed 4x4. all factory. about 7-8 months ago the schrader valve went bad and sprayed gas all over the motor. well we all know what happens when gas comes into contact with an extremely hot surface(drivers side exhaust manifold in this case).well needless to say the engine compartment caught fire and torched everything on the back and drivers side of my engine. now the list of repairs that have been made. lets see, new plugs,wires,distributor, distributor cap, rotor button,tfi module, clutch and brake master cylinders, clutch line and reserve, computer, complete rewire on the rear of the engine, fuel line,fuel pressure regulator, even redid the brake system(need do be done anyways) now for the big issue. i purchased a timing light from a local parts store to set my initial timing. i believe its supposed to be 10 deg btdc. so i set the timing to such and secured the distributor to let the engine to idle to normal temp(190) or so. but once the engine starts to warm up (around 120-150) depending on its mood it will start to pop,backfire,miss and carry on and then just shuts off. i can usually get it to restart after a few mins. but no amount of turning the distributor or operating the throttle by hand seems to smooth it out at all. so it runs great when its cold but as soon as it starts to warm up it carrys on and dies. any advice,thoughts,or remedies for this problem would be greatly appreciated. i need this vehicle to be in running condition asap im currently depending on friends,family and the local bus service for work and shopping etc. so once again any help would be greatly appreciated and thanks again.

 

[Rothskeli]

1st off let me say hey to everyone here. im new to the site. i stumbled over while searching for a solution to my problem so i figured why not give this site a try. now for my problem. i have an 86 bronco 2. 2.9,5speed 4x4. all factory. about 7-8 months ago the schrader valve went bad and sprayed gas all over the motor. well we all know what happens when gas comes into contact with an extremely hot surface(drivers side exhaust manifold in this case).well needless to say the engine compartment caught fire and torched everything on the back and drivers side of my engine. now the list of repairs that have been made. lets see, new plugs,wires,distributor, distributor cap, rotor button,tfi module, clutch and brake master cylinders, clutch line and reserve, computer, complete rewire on the rear of the engine, fuel line,fuel pressure regulator, even redid the brake system(need do be done anyways) now for the big issue. i purchased a timing light from a local parts store to set my initial timing. i believe its supposed to be 10 deg btdc. so i set the timing to such and secured the distributor to let the engine to idle to normal temp(190) or so. but once the engine starts to car accessories warm up (around 120-150) depending on its mood it will start to pop,backfire,miss and carry on and then just shuts off. i can usually get it to restart after a few mins. but no amount of turning the distributor or operating the throttle by hand seems to smooth it out at all. so it runs great when its cold but as soon as it starts to warm up it carrys on and dies. any advice,thoughts,or remedies for this problem would be greatly appreciated. i need this vehicle to be in running condition asap im currently depending on friends,family and the local bus service for work and shopping etc. so once again any help would be greatly appreciated and thanks again.

Your engine is not working properly. It could be major fault so ask a good mechanic to check it.

 

[adsm08]

Your engine is not working properly. It could be major fault so ask a good mechanic to check it.

Well gee, if we all had answers that helpful nobody would ever have to ask a question.




It sounds like you have a sensor signal not getting through somewhere. Since the problem starts when the engine gets to temp it is probably the coolant temp, air temp, or oxygen sensor that are at fault.

 

[1986bronco2]

i will definately look into those sensors as the primary cause of this issue. i know where the o2 sensor is located but not sure of the location of the other 2 that you mentioned. also i forgot to mention that there is a small square black "box" located on the driver side of the intake about 2'' by 2" next to the throttle linkage with 2 or 3 wirse coming from it. this was also damaged by the fire and i looked for it in my manual but i cant seem to find it and since i dont know what its called or what its purpose is i cant purchase a new one from the parts store. the engine also blows black smoke outta the exhaust when revved up before is carries on and dies. black smoke tell me that its running too rich when revved but still runs smoothly until it starts to carry on.

 

[RonD]

The warmed up part kinda narrows down the possible problems.

The engine computer(PCM) has two main settings, "open loop" and "closed loop"
"Open loop" is for when the engine is cold, or at WOT(wide open throttle).
In open loop the computer ignores most of the sensors, it runs the engine based on preset factory settings, which will cause the engine to run rich with advanced timing, like the choke did on carbureted engines.
This sounds like it is working on your truck.

In closed loop the computer gets information from all the sensors and bases the timing and fuel mixture on that information.
So if a sensor is feeding it bad info it will cause rough running.

What tells the computer to be in open or closed loop is the ECT(engine coolant temp) sensor, this is a two wire sensor similar to the 1 wire sender for the dash board temp gauge, and they are usually located next to each other near the t-stat housing.
If the ECT tells the computer the engine is always cold then when engine warns up it can be running too rich.


If you go here and look at the Electronic Engine Control diagrams for the 2.9l you may be able to ID what is what by color code also what might be unhooked.
http://www.therangerstation.com/tech_library/EDiagrams/index.htm

 

[sjr53]

There is an EGR Valve Position sensor next the the EGR valve. It has a vacuum line to the valve plus the wires to the harness

 

[1986bronco2]

where is the egr sensor valve located?