1986 Bronco II 2.9 code 18

[86BII since 1990]

The car starts and runs perfect until it warms to operating temp. It then lacks power and won’t stay running. Let it cool down and it starts and runs fine until it warms and symptoms repeat. Got a code 18 with code reader on KOEO. This is a stock BII 2.9 Automatic. 186,000 miles

in the last 5000 miles it has new fuel pumps, filter and tank removed and cleaned. New distributor and module. New spark plugs and coil. New EGR valve and sensor. New fuel pump sensor/regulator.

Code 18 refers to loss of tach signal and spout (spark output). Anyone know what is likely wrong and how to test or repair the problem?

PS If anyone has or knows where to get a factory breakout box for this model I would be a buyer.

 

[franklin2]

Think carefully. What were the symptoms before you changed the distributor, and then after? Exactly the same? A little different?

The reason I ask, I had this problem of bucking and rough running. Never could figure it out till I finally got the code 18 pop up. That told me distributor pickup. So I ordered a new pickup and cap and rotor. I went to pull the gear off the distributor to change the module, and I broke one of the teeth, my fault.

I looked and looked, and could not find a gear. So I went ahead and bought a Cardone rebuilt distributor. Installed it, and I was having the same problems, only a little worse. So I pulled the rebuilt distributor out and more carefully tore it down. I was shocked at all the old black carbon and sticky oil inside this distributor. And it still had the old original crusty pickup module. They had done nothing but clean up the outside and put it in the box.

So that new module I had bought, I installed in in the Cardone distributor, cleaned it up and lubricated it and put the new cap and rotor on it, and it drove like new. This was my first experience with Cardone rebuilt distributors, but not the last, I have other stories to tell, but they are for a 2.8 engine.

 

[86BII since 1990]

The problem occurred with the old OEM distributor. The new distributor has the same issue as before. I have the “old” original distributor. I will check it out more thoroughly.

I initially had the Ford dealer replace the ignition module on the original distributor with a Motorcraft module. It did not correct the problem. That is when I told them to replace the whole distributor and all its parts. They asked me if I wanted to use the new Motorcraft ignition module I had bought for the old distributor on the new distributor. I said yes so I muddied up the water a little bit by swapping parts. I am puzzled how to test for the specific issue and solution. I am reluctant to keep throwing parts at it.

 

[franklin2]

I was reading through this thread, and realized I may have made some confusion in it.

These 2.9's, and the 2.8's also, have what they call a "TFI" distributor. It uses a ignition module which bolts to the distributor on the outside of the distributor body.

The part I replaced that caused the code 18 on mine was the distributor pickup module which is located inside the distributor, and the distributor needs to be torn down to replace it. The pickup module inside the distributor is where the raw PIP signal originates from, and is sent to the computer. This is where the code 18 would come from if the computer for some reason missed some PIP pulses from the pickup module.

The computer or ECM, takes this raw PIP signal, and uses it for timing the injectors, and also takes this signal and "adds to it" and then sends it back to the distributor TFI module on what is called the "SPOUT" wire. The SPOUT wire is how the computer modifies the timing in the TFI module. The SPOUT wire is the one where you have to unplug the jumper to set the timing with a timing light, and then plug it back in.

 

[franklin2]

If you are confident in your distributor pickup module, Then I would look at the wiring bundle plugged into the distributor. Unplug it from the distributor and bring it up where you can see it. The PIP and SPOUT wires have a very low voltage signal on them, so they are inside a shield in the wiring bundle. Make sure this shield is there, and is not touching any wiring that is bare with worn insulation. I believe this shield is grounded on the computer end of the bundle. Make sure it is ONLY grounded on the computer end, and insulated on the distributor end. A ground on each end will cause noise in the cable.

 

[86BII since 1990]

Thanks for your responses. I will try to follow your directions. Once I had replaced the TFI module and the problem continued I suspected the pickup in the distributor so I had the whole distributor replaced. Still the problem persists. So it would appear, per your advice, the problem must lie outside the distributor.
I will remove the plug in the SPOUT wire clean the contacts and reattach the plug. I see the insulated wires. Looks like tin foil almost. I will move them and look for damage to the wires. I’ll remove the distributor plug to the wire bundle and look for bent or damaged pins. I’ll let you know if there is any improvement.

 

[SCMoore]

Following this thread because I have a similar issue. The stalling happens occasionally, it seems to idle fine, I'm getting what I believe is a miss fire when the RPMs are over 2200. I found the insulated wires and there was some corrosion at several spots on the bare ground wire. That doesn't seem to be enough to cause an issue, but I'll clean that and put it back together and see what happens. 86BII, I don't mean to highjack you post here. Someone let me know if I need to create a new one. I'm new to this forum stuff.

 

[franklin2]

Following this thread because I have a similar issue. The stalling happens occasionally, it seems to idle fine, I'm getting what I believe is a miss fire when the RPMs are over 2200. I found the insulated wires and there was some corrosion at several spots on the bare ground wire. That doesn't seem to be enough to cause an issue, but I'll clean that and put it back together and see what happens. 86BII, I don't mean to highjack you post here. Someone let me know if I need to create a new one. I'm new to this forum stuff.

You can get a timing light out, hook it up like you normally would, and before you start the engine, I usually clean off the harmonic balancer, and find the 10 BTDC mark, and put a short dot of white out on it. I then find zero TDC mark and put a long white mark on it.

You can then pull the spout connector and then check your timing, it should be rock steady at all rpms at 10 BTDC. If it's not, adjust it. It can be a little bit advanced, somewhere around 12 or a smige higher. If the mark is jumping all around, then something is worn out in the distributor.

You can then plug the spout back in, the timing should jump way up to possibly 20 or so. You can then rev the engine and see the timing mark move back and forth, the computer will be adjusting it. If it doesn't move, I would pull the codes on the computer.

 

[86BII since 1990]

On my original post. I removed the Spout Connector and cleaned the contacts as suggested, reinstalled the connector and the rough Running stalling problem is no longer happening. It seemed the connector came apart very easily and reinstalled with a satisfying click so I think it had become loose maybe by the mechanic who previously worked on the car. Apparently the spout must be connected for the engine to operate properly when warm in closed loop. It now runs fine up to a point.

On the test drive it runs and drives but lacks power when you step hard on the gas and then stumbles and has difficulty regaining a smooth idle. It seems like it is having trouble getting fuel. I am sure this is a completely separate problem from my first one. Fuel pumps are new, the tank is clean and spotless but fuel filter was last changed in 2018. I will change fuel filter. What else could cause the lack of power and near stall. Should mention you can feather the throttle until it will idle and run to recover a no load cruise without stalling.

 

[franklin2]

On my original post. I removed the Spout Connector and cleaned the contacts as suggested, reinstalled the connector and the rough Running stalling problem is no longer happening. It seemed the connector came apart very easily and reinstalled with a satisfying click so I think it had become loose maybe by the mechanic who previously worked on the car. Apparently the spout must be connected for the engine to operate properly when warm in closed loop. It now runs fine up to a point.

On the test drive it runs and drives but lacks power when you step hard on the gas and then stumbles and has difficulty regaining a smooth idle. It seems like it is having trouble getting fuel. I am sure this is a completely separate problem from my first one. Fuel pumps are new, the tank is clean and spotless but fuel filter was last changed in 2018. I will change fuel filter. What else could cause the lack of power and near stall. Should mention you can feather the throttle until it will idle and run to recover a no load cruise without stalling.

You can double check the timing also and make sure it's moving when you rev the engine.

The pickup in the distributor produces a square wave. This square wave is amplified by the TFI module which turns the ignition coil on and off to fire the plugs. This system will work on it's own without the computer, but it doesn't have the ability to adjust the timing. So it will run the engine at whatever you set the dist at with a timing light, which is 10 degrees BTDC. But;

The square wave from the pickup is also sent to the computer. The computer modifies it and then sends it back on the spout wire with the spout connector. That is what the spout connector is for, to give or take away the computer control. If your spout connector is giving problems again, the timing will not be advanced, and that would give you power problems, even though the engine is running ok.

 

[Cees Klumper]

I am getting an occasional stall and code 18. On my truck, a PO has already replaced part of the wiring that goes to the distributor, the last couple of inches including the flat (5 or so wire) connector to the TFI module. These are widely available so they apparently fail frequently: either the wiring inside or the connector itself becomes wonky. It appears to have been done pretty well, but just to be sure I bought another new connector + wires, and will replace the current one soon. I did also take out my spout connector thingy and cleaned the connections, they appeared to be good. So far no new stalling issue, but then again sometimes the truck will run fine for over a 100 miles, then on a 5 mile trip stall 3 times. It always starts right back up again somehow, which I also find odd, but it does for me point to a wiring / connector / poor connection issue.

On your low-power issue 86BII, make sure you have the ignition timing set correctly as franklin2 notes, as poor ignition timing has a huge impact on the amount of power the engine can make. Also, you may have a vacuum leak somewhere (these engines, at least the fuel injected ones, which I don't think you have) are very sensitive to vacuum leaks) and/or vacuum lines may have gotten 'switched': there are vacuum ports before, and after the throttle body. On my truck, a PO had mistakenly connected two lines wrong, causing among other things rough shifting of the automatic transmission. Once I swapped them back, things improved quite a bit.