Engine 1986GT distributor prob

Magnet86

5 Year Member
Jul 21, 2018
92
12
18
Bedford, PA
Hello all. First post. Need serious help. 1986 GT. Stock.

I replaced the distributor about a week ago. When I reinstalled it, I had it a little off but the car ran good and strong. Likely missed a tooth as others say. Had to rotate the thing too far for the TFI module although I have already relocated that. I tried to get the diz back to a better position today and can't seem to get it right.

I removed the fan as I also replaced the fan clutch. Rotated the engine by hand until TDC according to the timing marks. Repositioned the diz with the rotor pointing at number one cylinder terminal, almost straight back towards the firewall. Car cranks but does not start. The ground wire that attaches right at the negative battery terminal is melting. I checked all ignition wiring for proper routing and connections. All is good.

I've been under the hood of this car for many months trying to get it back on the road and no luck. Like fifteen months. Also have a new job that takes my time and I don't work on the car when it is too hot or too cold out. Getting older.

Any advice is welcome as I'm lost at this point.

Thanks.
 
there is no such thing as being off a tooth on these motors. If the distributor is properly phased then it will work. There is a sticky/archive on how to set the motor to TDC on #1 as well as many youtube videos.
 
Hello all. First post. Need serious help. 1986 GT. Stock.

I replaced the distributor about a week ago. When I reinstalled it, I had it a little off but the car ran good and strong. Likely missed a tooth as others say. Had to rotate the thing too far for the TFI module although I have already relocated that. I tried to get the diz back to a better position today and can't seem to get it right.

I removed the fan as I also replaced the fan clutch. Rotated the engine by hand until TDC according to the timing marks. Repositioned the diz with the rotor pointing at number one cylinder terminal, almost straight back towards the firewall. Car cranks but does not start. The ground wire that attaches right at the negative battery terminal is melting. I checked all ignition wiring for proper routing and connections. All is good.

I've been under the hood of this car for many months trying to get it back on the road and no luck. Like fifteen months. Also have a new job that takes my time and I don't work on the car when it is too hot or too cold out. Getting older.

Any advice is welcome as I'm lost at this point.

Thanks.
Putting the distributor back in and setting the timing.

Revised 15-Apr-2016 to add fix for TFI hitting the thermostat housing while trying to set the base timing at 14°.

You can forget about anything beyond this point if you don't have access to a timing light. You will never get the timing set right without one.

Note: If you don't have access to a timing light, most of the larger auto parts stores will rent or loan one if you have a credit card or leave a cash deposit.



Putting the distributor back in is fairly simple. Pull #1 sparkplug, put your finger in the sparkplug hole, crank the engine until you feel compression. Then line up the TDC mark on the balancer with the pointer on the engine block.

The distributor starts out with the #1 plug wire lined up at about 12:00 with you facing it. Align the rotor to about 11:00, since it will turn clockwise as it slides into place.

Align the distributor rotor up with the #1 position marked on the cap, slide the distributor down into the block, (you may have to wiggle the rotor slightly to get the gear to engage) and then note where the rotor is pointing.
If it still lines up with #1 position on the cap, install the clamp and bolt. If not, pull it out and turn 1 tooth forwards or backwards and try again. Put the #1 spark plug back in and tighten it down, put the clamp on the distributor, but don't tighten it too much, as you will have to move the distributor to set the timing. Note that there is no such thing as one tooth off on a 5.0 Mustang if you follow the spark plug wire order on the distributor cap. If it doesn't align perfectly with #1 position, you can turn the distributor until it does. The only problem is that if you are too far one way or the other, you can't turn the distributor enough to get the 10-14 degree optimum timing range. If the TFI prevents the distributor from being turned enough to get 14°, there is a simple fix. Pull the distributor out and turn the rotor 1 tooth counterclockwise Don't move the wires from the positions shown on the cap on fuel injected engines!!!! The #1 position cast into the cap MUST have the spark plug wire for #1 cylinder in it. Do it differently and the timing for the fuel injectors will be off. The computer uses the PIP sensor to time injector operation by sensing the wide slot in the PIP sensor shutter wheel. If the injector timing of #1 and the firing of #1 do not occur at the right time, the injector timing for all other cylinders will be affected.

Setting the timing:
Paint the mark on the harmonic balancer with paint -choose 10 degrees BTC or 14 degrees BTC or something else if you have NO2 or other power adder. I try to paint TDC red, 10 degrees BTC white and 14 degrees BTC blue.

10 degrees BTC is towards the drivers side marks.

Note: setting the timing beyond the 10 degree mark will give you a little more low speed acceleration. BUT you will need to run 93 octane to avoid pinging and engine damage. Pinging is very hard to hear at full throttle, so it could be present and you would not hear it.

Simplified diagram of what it looks like. Not all the marks are shown for ease of viewing.

ATC ' ' ' ' ' ' ' ' ' '!' ' ' ' ' ' ' ' ' ' BTC
---------------- > Direction of Rotation as viewed standing in front of the engine.

The ' is 2 degrees.
The ! is TDC
The ' is 10 degrees BTC
Set the timing 5 marks BTC. Or if you prefer, 5 marks towards the driver's side to get 10 degrees.

To get 14 degrees, set it 7 marks BTC. Or if you prefer, 7 marks towards the driver's side to get 14 degrees.

The paint marks you make are your friends if you do it correctly. They are much easier to see than the marks machined into the harmonic balancer hub.

At this point hook up all the wires, get out the timing light. Connect timing light up to battery & #1 spark plug. Then start the engine.

Remove the SPOUT connector (do a search if you want a picture of the SPOUT connector) It is the 2 pin rectangular plug on the distributor wiring harness. Only the EFI Mustang engines have a SPOUT. If yours is not EFI, check for a SPOUT: if you don’t find one, skip any instructions regarding the SPOUT
Warning: there are only two places the SPOUT should be when you time the engine. The first place is in your pocket while you are setting the timing and the second is back in the harness when you finish. The little bugger is too easy to lose and too hard to find a replacement.

Start engine, loosen distributor hold down with a 1/2" universal socket. Shine the timing light on the marks and turn the distributor until the mark lines up with the edge of the timing pointer. Tighten down the distributor hold down bolt, Replace the SPOUT connector and you are done.

The HO firing order is 1-3-7-2-6-5-4-8.
Non HO firing order is 1-5-4-2-6-3-7-8

attachments\51122
 
Managed to get the thing to actual top dead center and adjusted the distributor correctly. Car fired up and wanted to die for about three minutes, then ran well although the idle was very high. Settled down and I adjusted timing with a timing light but once the SPOUT connector is reinstalled the car 'self-adjusts' and the timing mark moves from where I had it, about 8 degrees BTC to what appears to be ATC. The white out marker at 8 degrees BTC show sup to the left of the pointer when checked with the light. But it does run and sound good. I backed out the throttle screw slightly and idle is maybe 900 RPM. I need to check that again. I haven't driven the car yet as its a little hot here but will do so very soon. Car does sound awesome and smooth. Excellent throttle response. Just a high idle. I can live with that if necessary. Plus the diz is positioned so that if the TFI module was on it, the diz would be spun too far to actually be where it is. I'll keep checking but at this point, I don't want to mess with it again. I do have the previous diz with a new stator installed and maybe it would sit more 'normal' but if things are cool, I say let's leave it alone and enjoy. Need to charge the AC and drive.
 
Managed a test drive this evening. Went one block down and returned. All good. Went two blocks away and back and once again, all good. Great throttle response and no hesitation. But car is rather warm. Temp gauge shows pointer at the A in NORMAL. Turned on the heat to be safe. Took a third jaunt that was maybe 8 blocks long. About a third of the way along the engine hesitated on acceleration and seemed to lose some power. I made it back but was worried for a spell. Car did not overheat, nothing broken, not sure what happened. Pulled codes. KOEO 11. KOER only showed 44. I've had trouble with 44/ 94 lately. Tested all components earlier this month and the whole smog system checked out good. Proper vacuum routing but definitely need to check it all again. Also want to check timing again. Any advice is most welcome. Thanks.
 
Swapped distributors today. The original is back in although it has a new Ford stator inside. No real problems but the diz is rotated as far as possible and the timing still feels off. Not sure about power or hesitation as I didn't test drive it. Without the shunt/ timing jumper the thing is close according to timing marks but still off. Once the jumper is reinstalled the computer takes over but the idle is lower now than before. Mystery and about ready to hand it off as I have no idea what to do next. Ideas welcome. If anyone is nearby... well we'll see.
 
Guess no one wants to help.
Repositioned the distributor and timed the car again. Without the jumper the timing is spot on according to the timing marks. When the jumper is put back it goes crazy. And tonight I turned it on just to see if it would turn over and it could not find idle to save its life. From maybe 1300 to 250 RPM for about three minutes. Not sure about this car's future. Can't find a happy idle nor time it correctly.
 
The best advice I can offer you comes from @jrichker ,he and a few others took a lot of time to compile these checklists-though they are a TON of info and can be overwhelming-if you go through the lists and follow the instructions to the T. Your surging idle and timing issue will be cured. Sorry for the delay in responding back to you-but ya know, life happens lol here’s the link-
https://www.stangnet.com/mustang-forums/threads/help-me-create-the-surging-idle-checklist.698148/
And here are the lists (next post)
 
You're fixated on this timing thing, lets ask some questions. How many miles on the engine. Are the vacuum lines good and in the correct places. You mentioned a ground wire getting hot, you may need to clean and replace this wire and make sure it's attaching point is clean. Is the harmonic balancer in good shape, they can become brittle and become detached making the timing marks off. Keep on mind that once you set the timing and plug the spout in the computer takes over the timing and adjusts the timing based on what other stuff it 'sees'. So the timing will appear to jump around.
 
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Today I checked the throttle position sensor and found the voltage to be high. It wouldn't adjust by turning it and not wanting to drill it I thought about the throttle stop screw. It has been adjusted numerous times over the years. I left the digital meter hooked up and turned the screw counter-clockwise and the volts at the TPS came into spec. The idle seems a little low but the engine is smooth now. After lunch I checked it again and after heating up I did have to turn the screw clockwise a little to get it to not shut off when I removed the IAC connector. It seems to idle better but still low. I need to hook up the shop tack. Need advice on that one. Its an older tach with directions that don't make a lot of sense. I think the car is better and there is no surge but I want the idle a little higher and stable. May test drive this evening, not sure. Getting hot again and well, I'm lazy when the mercury hit 85 or more. No garage. Thanks for the help. Those lists are incredible.
 
You can try to reset the computer by unhooking the battery and turn on the head lights for about 20 to 30 minutes the turn off the lights and hook the batter up and drive it for an hour or so and see how it acts, also check for codes.
 
I adjusted idle again and the TPS to make sure all is well. TPS voltage at idle is 1 volt. Idle speed is around 650 with the shop tach. Idle is quite smooth and steady. I test drove the car today and no overheating and it had plenty of power- great throttle response. No hesitation. Sounded great. I'll keep at it and just drive it to make sure its fine. Car is fun again.
Cheers.
 
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Car still runs great. I drove a few trips today and no hesitation or lack of throttle. Car did run a litle warm according to the temp gauge but nowhere near overheating. I pulled codes after the fourth trip and all I had was 44 for the KOER. I'd guess there is some carbon in the head limiting or (hopefully not) blocking the smog port/ tube inside the head. However, the car does not want to start after the initial startup. Sounds like a near dead battery but after maybe 2 seconds it cranks and fires right up. I'll check voltage but not sure why it would do that. Once it is completely cool it fires right up within a second. Maybe alternator not charging? I think the battery may be a little weak as after I bought it- its a Motorcraft battery to boot- there was a week of not using the car back when I had idle and timing issues. Maybe a short somewhere. Need to run if for a short trip.