EFI wows, about to scrap it!

[DezertRunner]

Hello all, I am finally ready to get back on this project and am still having a hell of a time getting this running perfect. Car only has 62,xxx and is a one owner car with all receipts from dealer maintenance, and I know the odometer has not rolled over being 162,xxx. Here is some of what I have already done.

New : spark plugs, cap, thick ford racing wires, fluid/filter in trans/engine/diff, TBS/IAC, cleaned EGR, set timing, vac lines

I am having a slight problem with how it is running and trying to track it down. It has a hang idle after you blip the throttle (while in park) and after coming to a complete stop sometimes idle goes so low it dies. For some damn reason it drives perfect with the spout disconnected, which I am doing for the time being. Leads me to believe its a timing issue, I have timed it correctly and with spout back in it does advance.

This motor has a used Motorcraft distributor from a 89 Mustang, I can verify buy the paint pen marks on it, looks to be from a wrecking yard. Do you think I should go ahead and replace it anyway?

Please any suggestions?

I am about to scrap the EFI all together and just Carb it...

[adam.w.ackerman]

TFI/ICM


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[kishy]

Er, yes. Continuing this here from the other thread...

PIP refers to the "ignition pickup", which is inside of the distributor. It is replaceable but requires some effort to do so. If the PIP is completely nonfunctional the engine will not run at all. Intermittent failure is possible but seems to be uncommon.

The module mounted on the side of the distributor is the TFI (ignition) module. Usually if it's going to misbehave, it will happen when the engine is hot and at least work kinda OK when fully cold even if it's failing.

There are two types of TFI module, black and grey, and they can't be mix-and-matched. Our cars need the grey one. Is the one on your used distributor grey or black?

Stupid question but are you 100% sure the car is a 1986? 1985 used a totally different fuel injection system and has its own demons especially around idle speed. If you have a round air cleaner on the middle top of the engine, it's the older system. If you have the large aluminum intake that says 5.0 EFI on top then it's the newer system.

TFI/ICM

It sounds like a likely possibility.

But just to throw it out there, I had the "runs fine with SPOUT unhooked but runs like garbage with it connected" thing with my 84 and it was the coil (which seems like nonsense but I promise it isn't). CFI and SEFI have their differences but TFI ignition is TFI ignition.

[gadget73]

what vehicle and what engine are we talking about here? Anything not stock would be useful to know about.

Do the timing marks hold steady when you check it? Sloppy timing chains make these go stupid. 1985 and older, and 1987 specifically often had a shitty single row chain with a plastic cam gear that wears out way sooner than you'd believe possible.

Is the firing order correct on the distributor? #1 has to be going to the #1 plug for it to not be stupid. Can't jump them around like on a carb setup. If the TFI and PIP aren't right, the rest of it isn't right either. Both can get old age sensitive or heat sensitive. The insulation on the coils can also fail and it will arc out to the core, sometimes you'll see it looking slightly chalky in the corners or wherever the insulation is failing.

Have you ever scanned it for codes?

Part of the idle control is by timing, part is by the idle air control motor, or IAC. If the SPOUT is out, there is no timing control. If the IAC sucks, well, that doesn't work right either. Non-OE ones tend to suck.

[DezertRunner]

TFI module, that is what I meant. I am 100% it is an 86, it has the same as Mustang intake just on the opposite side. And correct, it runs way better/smoother with spout disconnected and does not stall.

[DezertRunner]

what vehicle and what engine are we talking about here? Anything not stock would be useful to know about.

Do the timing marks hold steady when you check it? Sloppy timing chains make these go stupid. 1985 and older, and 1987 specifically often had a shitty single row chain with a plastic cam gear that wears out way sooner than you'd believe possible.

Yes, with spout disconnected timing is set perfect and steady. This is a 1986 Ford LTD 5.0

Is the firing order correct on the distributor? #1 has to be going to the #1 plug for it to not be stupid. Can't jump them around like on a carb setup. If the TFI and PIP aren't right, the rest of it isn't right either. Both can get old age sensitive or heat sensitive. The insulation on the coils can also fail and it will arc out to the core, sometimes you'll see it looking slightly chalky in the corners or wherever the insulation is failing.

Yes, non HO firing order, I have checked and verified. All new plugs and heavy duty Ford racing wires routed correctly

Have you ever scanned it for codes?

Saddly No, I was going to pick up a OBDI scanner, the whole light flash counting has me procrastinating...

Part of the idle control is by timing, part is by the idle air control motor, or IAC. If the SPOUT is out, there is no timing control. If the IAC sucks, well, that doesn't work right either. Non-OE ones tend to suck.

I installed a brand new Motorcraft IAC, and have set the voltage/adjustment under .999 like suggested.

[DezertRunner]

I also verified Map sensor working, when unplugged while running it dies. Only sensors left I think that I haven't looked at are coolant temp and O2, which I don't think would describe this problem.

[DezertRunner]

There are two types of TFI module, black and grey, and they can't be mix-and-matched. Our cars need the grey one. Is the one on your used distributor grey or black?

I am pretty sure it is grey, I will check tonight though.

**Edit, I am not the one who installed this distributor used, it was the PO**

[adam.w.ackerman]

So the TFI/ICM has been replaced or not?

Did you or did you not replace the PIP in the distributor? Does not matter if it was used or not.

If you did both did you use motorcraft parts or did you cheap out?

If all that checks out then it is probably the ECM, these are notorious for having bad caps. Pull the ECM and open it; look for bloated or leaking capacitors. You can get reman units for like $130 or you can try to find one in a yard to test with.


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[DezertRunner]

So the TFI/ICM has been replaced or not?

Did you or did you not replace the PIP in the distributor? Does not matter if it was used or not.

If you did both did you use motorcraft parts or did you cheap out?

If all that checks out then it is probably the ECM, these are notorious for having bad caps. Pull the ECM and open it; look for bloated or leaking capacitors. You can get reman units for like $130 or you can try to find one in a yard to test with.


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I did not install it, I received it this way and became aware when I saw the paint pen markings on it from a wrecking yard. It is a used OEM motorcraft distributor from a 89 5.0 Ford Mustang installed on my Vic. That's why I was asking if it was compatible or not and the whole root of my problem, could still be faulty since it is so old and was not new.

I do not want to have to buy a new ecm just hoping it will fix the problem. Seems that is what I have done so far replacing everything else hoping it would fix the problem, and figured it would not hurt to replace since everything is so old anyway, have only used motorcraft products thus far.

That is where I am at, my wits end with this EFI stuff, and about to scrap it all and go carb, I like carb trouble shooting simple and easy. I have researched on here and far more than I would like to admit, that is why I created this thread hoping to pick your brains. I thank and appreciate anyone who has any insight!

[DezertRunner]

Also, I got the bronze tv bushing as suggested everywhere, the 86 must be different as it does not look the same and could not use it. Shifts great though, that is not a problem. Fluid was good, but replaced fluid and filter anyway as peace of mind.

[gadget73]

86 doesn't use a TV bushing.

The ECM rarely goes bad but the caps are like 10 bucks to replace, its not a big deal if you know how to solder. The ones in mine were leaky and green and the car ran fine. No way would I spend that much money on a reman ECM or a junkyard one that is every bit as old.

Bad temperature sensors can screw with things. Fuel mix is done with engine speed, engine load, and air density. Density is calculated from air and coolant temperature sensors.

http://www.grandmarq.net/oldfuelinjection/page10.html
http://www.grandmarq.net/oldfuelinjection/page13.html

There is an orange ground wire that needs to be connected at the rear of the engine. Its the connection between the engine and the ECM for all of the sensor grounds. Without it, the values the ECM sees are all screwed up. It often breaks off the eye, usually its on one of the rear-most lower intake bolts.

Vacuum leaks also make it act generally stupid, so check the condition of the vac lines.

That whole 0.999 volt thing is mostly bollocks. The ECM self-adjusts anywhere from about 0.8 volts to 1.1 volts. As long as its in that range, it'll be ok. Outside that range it will do stupid things, but usually it codes. If its not out of the realm of self-test sanity though it'll be a pain in the ass.

[DezertRunner]

86 doesn't use a TV bushing.

The ECM rarely goes bad but the caps are like 10 bucks to replace, its not a big deal if you know how to solder. The ones in mine were leaky and green and the car ran fine. No way would I spend that much money on a reman ECM or a junkyard one that is every bit as old.

Bad temperature sensors can screw with things. Fuel mix is done with engine speed, engine load, and air density. Density is calculated from air and coolant temperature sensors.

http://www.grandmarq.net/oldfuelinjection/page10.html
http://www.grandmarq.net/oldfuelinjection/page13.html

There is an orange ground wire that needs to be connected at the rear of the engine. Its the connection between the engine and the ECM for all of the sensor grounds. Without it, the values the ECM sees are all screwed up. It often breaks off the eye, usually its on one of the rear-most lower intake bolts.

Vacuum leaks also make it act generally stupid, so check the condition of the vac lines.

That whole 0.999 volt thing is mostly bollocks. The ECM self-adjusts anywhere from about 0.8 volts to 1.1 volts. As long as its in that range, it'll be ok. Outside that range it will do stupid things, but usually it codes. If its not out of the realm of self-test sanity though it'll be a pain in the ass.

Gadget I appreciate your insight, you are one of the veterans around these parts. I have no problem soldering new caps in an ecu if that is what is needed. With such a low mileage un-molested car, I have to ask...

What would you do? This is not my daily driver, Carb this sob?

[adam.w.ackerman]

If the ICM, the grey box on the side of the Distributor, has not been replaced by YOU then replace it. The distributor is the same for all 302 engines.


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[adam.w.ackerman]

This EFI system will out perform any carb setup, especially on a stock engine; they are not hard to maintain you just have to learn the terminology. Once they are set you leave them alone.


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