Ignition timing not moving with RPMs

[te4gan]

I have been fiddling with my timing recently because I have been having issues where the timing moves backwards when you put it under higher RPMs and I would lose a lot of power. I could not figure out why. I put in a remanufactured distributor with new rotor, cap, and module.

Now, the timing does not advance or retard at all.... stays where I set it no matter how many RPMs.

I am wondering if anyone on this forum has had similar issues and I am looking for ideas/next steps.

Thank you in advance.

[1986F150Six]

Is the SPOUT wire connected?

[Gary Lewis]

Good point, David.

Another issue could be that the system is limp-home mode.  If the computer senses that something isn't right it'll lock the timing and there will be no advance of any kind.

I'd pull the codes and see what is ailing it.

[1986F150Six]

I would think that improper timing at higher [that's funny, as we are talking about maybe 2500-3000 RPMs for a 4.9L, right?] RPMs would point to the MAP sensor or perhaps the computer, itself.

[te4gan]

Hey guys,

Thank you for your responses. I have been extremely busy with college but I was able to dig around today.

The PO had the emissions control completely taken out. I am not sure why, but they did.

So with them taking that out, I found today that they decided to disconnect the power to the EEC-IV so that it would not notice the emissions control being gone.

I believe, and would like feedback if I am wrong, that this is what causing the issues with the timing advancing with higher RPMs. The computer was not on and therefore was not giving a signal to the distributor to advance.

I am trying to figure out my next options. Could I install a vacuum advance distributor, and keep the EEC-IV unplugged and be fine?

I also ran my code reader and the KOEO test did not finds any faults. The KOER ran 13, 41, 72, 73 but my buddy was giving it some gas while running code just to keep the engine alive. Engine ran perfectly fine while idling when the EEC-IV was unplugged.

I am wondering if anyone has done anything like this or has any thoughts about what to do.

[85lebaront2]

If you still have the feedback carburetor it will not have the correct mixture with the system not connected. The EEC-IV uses RPM, manifold vacuum, O2 sensor, coolant temperature, throttle position and EGR position to arrive at the proper mixture and timing and also controls the idle speed. Disabling part of it puts it into limp mode, where it will get you there, not efficiently though. If the EEC is connected, the timing connector by the distributor needs to be unplugged to check the basic timing otherwise the computer will keep moving it on you.

[1986F150Six]

te4gan wrote

Hey guys,

I am wondering if anyone has done anything like this or has any thoughts about what to do.

Here is an old thread which will be beneficial to you:

https://www.ford-trucks.com/forums/966602-duraspark-ii-conversion-for-86-i-6-a.html

[ratdude747]

No bueno then. No computer means no ignition timing change or carb mix control. You'll either have to piece it back together, set base timing (VERY IMPORTANT!), then power on the ECU. My 84 had the same thing (emissions present, ECU power removed, base timing set crazy advanced to "compensate" for the lack of timing control) and I didn't set (or even verify) base timing before powering up the ECU... and such didn't run well at all and such's pinging very well may have been what broke my upper compression rings (which forced a rebuild).

Alternatively, you could remove the system the rest of the way and convert to DSII like described above. That will give you a vacuum advanced distributor.