no start; 1988 carb. dist wire to ecu showing resistance

[bravekozak]

That baro wire should have nothing to do with a no start condition.

Are you running the stock ignition coil? If not, then you probably fried the ignition module inside the didtributor. Ask me why I have a resistor for my coil.

[Movin]

I have almost battery volts when I unplug the baro. Both yours and mine are normal for our altitude. Also this wire goes to the center plug ( #2 ) pin H.

I think brave is right, when the ignition module is switched one way it is shorted but switched the other it runs. The computers on these are pretty tough, the modules reside in a much harsher location and fail much more often.

If your tach goes nuts in the low altitude position and the car will not fire, but it runs with the wire disconnected from the disty, the module must have a bad diode allowing feedback out to the coil negative and tach circuit. That is how a coil with no resistor could have enough spikes to damage the module.

Working retail anytime a module or ignitor fails we replace the coil too. Just to make sure high side voltage is not arcing to the low side under high stress loads.

EDIT

There is a Blue with Orange wire from the cluster going into the ecm connector that you are unplugging...Maybe your tach is bad ?

[tooldude]

It now appears that disconnecting the tach may allow the engine to operate normally if the new module has not been damaged. Has that been tried? The missing tach information really shed some light on this, since the module had been replaced. The coil, tach, or both must now be faulty like Movin' was saying. Now this whole thread makes sense to me. It caused me to research into how the altitude compensation works also. Ford did not lay that information out clearly in the FSM.

[katscan]

I understand parts of this; but really not much. I do have 5.73 volts at the ecu blue orange wire at the ecu yellow plug. At the distributor connector; I have 12 volts. The left yellow plug on the computer goes to the white tubular connector and the vacuum solenoid. I would like to know what that part is called; it is a 'can shape with 4vacuum tubes on it. Anyway; disconnect the left most ecu yellow plug and the car starts.( If the yellow left ecu plug is plugged in; then I have that no spark condition. Distributor will spark out of the car; put it in and it wont.) But if my "cannister vacuum thingy has shorted" i would like the name of it cause I haven't found it in two weeks. Thanks. Jeff

[katscan]

ok, I am going to put another ign module on in the morning. Still need to know what that vacuum motor is> manual says stepper motor; but I can't find it anywhere on the web. i need it to get the idle right.

[Movin]

See if it will run without the cluster. Pull your instruments out behind the steering wheel and unplug the round connector with that Blue-orange stripe wire in it.

If you do the module do the coil too just because.

[tooldude]

The entire "can" assembly you're referring to is called a Feedback Carburetor Actuator (FBCA). It contains 2 needle valves and orifices called Air Bleed Control Valves (ABCV), opened & closed by the stepper motor. You will find it referred to by both names and acronyms in different manuals, but meaning the same part. Its function is to control the fuel mixture by admitting air into the slow & primary ports. It was not available separately but came on the carburetor body. I doubt there was ever an aftermarket part made. However, I don't think you need to suspect that part at this point unless there is some previous history on that. I'm assuming you removed that plug on the ECA to disconnect the BL/O wire. That also disconnected the FBCA, but I can't say if that alone would kill the idle - may totally be ignition. I believe you need to resolve this ignition problem first, which may be the cause of associated problems. Reread his posts, Movin' already described what the most likely problem is and wisely suggested disconnecting the entire cluster. Try running the engine with only the cluster disconnected - that's free. If that solves it, troubleshoot the cluster but replace that old coil. Still isn't working? Don't change just the module because if the last replacement is bad, whatever killed it will kill the next one too - but maybe it's good? Try a new coil first, then a module (isn't that module expensive?). Be sure the plug wires are good and not arcing.

[katscan]

I will keep everyone updated I will take more readings with different items disconnected. Thanks for the name of that part. As far as the eca plug. No. the BL/O wire is not at that plug location. It is on the center plug. The tach is not "connected to that plug either. Just the ABCV part and a couple grounds/ BL/W and W/r power feeds. Thats whats so baffling. I have disconnected the tach. No start. Like I said; I will take more voltage readings with different parts unpugged and plugged in. More data the better. I have another new Ign Module; but don't want to fry it before I get more data off other components while this current ign module is on. Thanks.

Also, can the carburetor run without the ABCV hooked up? Maybe run without electronic control? Would need tube routing. Thanks again

new module; new coil. New wires; The car is a gem. I had just finished putting 15k miles on it. 1k a week. Delivering papers. Previous owner was the only owner. Turned a corner and it died one night. I really love the car and am dedicated to getting it right.

[katscan]

I will keep everyone updated I will take more readings with different items disconnected. Thanks for the name of that part. As far as the eca plug. No. the BL/O wire is not at that plug location. It is on the center plug. The tach is not "connected to that plug either. There is no BL/O wire going to the cluster; 1988. Just the ABCV part and a couple grounds/ BL/W and W/r power feeds. Thats whats so baffling. I have disconnected the tach. No start. Like I said; I will take more voltage readings with different parts unpugged and plugged in. More data the better. I have another new Ign Module; but don't want to fry it before I get more data off other components while this current ign module is on. Thanks.

Also, can the carburetor run without the ABCV hooked up? Maybe run without electronic control? Would need tube routing. Thanks again

new module; new coil. New wires; The car is a gem. I had just finished putting 15k miles on it. 1k a week. Delivering papers. Previous owner was the only owner. Turned a corner and it died one night. I really love the car and am dedicated to getting it right.

[katscan]

I'm sorry, the last post is confusing.
1. No Bl/O wire at the cluster. 1988;
2. No BL/O wire at the left eca plug. 1988.
3. Disconnected instrument cluster; no start.
4. Only wires on the left ecu plug are to the ABV valve thing and two grounds and a Bl/w and W/r power leads.
5. Unplug the left ecu plug; car starts and runs with my foot on pedal. dies upon release of pedal.
6..Plug in ecu plug and no start no spark condition.
7. New coil, and old coil act the same. New ign module. New wires.
8..I am going to get as much data; voltage readings and post when I can.
9. Can car run without the "neede air" part?
10. I was impressed with the electronics on this car keeping the idle between 750 and 800 when running.

[Movin]

My 88 carby has no tach but the 89 carby wiring diagram shows that wire for the tach. You have the same wire if you have a tach it just must be another color.

[Movin]

Does it run with the bl-or wire disconnected from the disty?

[katscan]

I would like to find that wiring diagram. no, car wont start with Bl/or wire disconnected from dizzy. I do have a green wire that plugs into the tach for shift light possibly; I don't have a shift light on my cluster though. I will check it (ecu plug to tach connector for continuity to see it is the same wire) I will be taking more values tomorrow and hope this will give us some more insight. Thank you so much for your interest.
Talked to a fellow mechanic, I am too,, who had a festiva or 3. Said he had to junk it years back, couldn't get the spark,. I told him I disconnected my computer to get the spark and I saw his face shocked. and disappointed. I know he must have tried everything.

[bravekozak]

Here are the wiring diagrams.

The main reason I threw out my feedback carb was that I didn't want to burn any brain cells trying to figure out why it didn't work properly.
I switched to Mikuni carbs instead and discarded the ECU along with the barometric. The only thing going to my carbs are throttle cable, manual choke cable and gas. Good luck figuring it all out.

[Movin]

Sweet! Dunebuggy wiring too!! At least it must be pretty simple.

If I put mikuni carbs on off of a 105 hp snowmobile will my stock
1.3 make 105hp too? lol wish...