My '85 MGM, "Maisa"

[Arquemann]

Spacers came in and went in today. Stock nuts would've stuck past the 25mm spacer, I could've made it work with the 8mm pancakes on top, but I scrounged up 10 shorter nuts from my dad's filing cabinet o' treasures. This way I could tighten the pancakes between the hub and 25mm spacer, so it was easy to center.



With the spacers on it looks ... normal. To my eye it's visible and it looks wide now
I'll probably get some wider rear wheels at some point, since one is worn on the inside and the other has runout. I can get white stripe tires atleast 235 wide. White letters would be fun too, but I'd have to buy 4 since mismatching is a no-go.

[Arquemann]

Any cheap tricks to add a little oomph to CFI? Lip flip probably isn't a thing here.
I still haven't scored a job and I'm getting acutely bored.

[sly]

Nope. CFI doesn't like any of that and it'll run like ass if you try. It either runs as intended or badly.

[gadget73]

flipping the air cleaner lid won't bother it. Won't do anything, but it won't make it run worse either. Might make a small bit of extra noise.

Dual exhaust will help slightly, but possibly not really enough to notice. Otherwise there really isn't all that much to be done with it beyond just making sure everything is working like it should be. Possibly you can bump the timing a teeny bit and get a little more throttle response but there is only so much you can go before it pings.

[Arquemann]

Figured as much. There's no donors to pull a dual exhaust from and exhaust shops are expensive. Timing should probably stay as is, feels relatively responsive, though I've never had this thing ping, even with an inoperative EGR and regular gas.
I remember the tudor that's been the PoTM for the last forever had a hotrodded CFI, but can't recall if it had aftermarket engine management...

Onto another thing: The car needs throttle for a while after a cold start to stay running, wasn't the case before I adjusted the idle down to what it's supposed to be. At what temperatures does the high idle mechanism come to play? Mine's broken and I could imagine fixing it if it helps.
I'm talking outside temps at around 10-25°C (50-80°F).

[87gtVIC]

I remember the tudor that's been the PoTM for the last forever had a hotrodded CFI, but can't recall if it had aftermarket engine management...

I got a chuckle out of that.

[Arquemann]

It is what I thought, the thread doesn't mention anything about engine management anywhere.

Nothing done to the CFI unit, just rebuilt the unit with new injectors, new FPR, new TPS sensor, and cleaned the bejeezus out of it. My other mods are in my signature.

And the sig goes like this:
"CFI, K&N Filter, Edelbrock Lower Intake, 1.6 Roller Rockers, E7 Heads, BBK Shorty Headers, Summit H-pipe, Hooker Max Flow Mufflers, E-Fan, 3G Alternator, Race Crank Pulley, Bilstein Rear Shocks, KYB Front Shocks, Front Lowering Springs, FTI 2400 Stall Converter, PA Perfromance Valve Body, Motive 4.30 Gear"

[DerekTheGreat]

Figured as much. There's no donors to pull a dual exhaust from and exhaust shops are expensive. Timing should probably stay as is, feels relatively responsive, though I've never had this thing ping, even with an inoperative EGR and regular gas.
I remember the tudor that's been the PoTM for the last forever had a hotrodded CFI, but can't recall if it had aftermarket engine management...

Onto another thing: The car needs throttle for a while after a cold start to stay running, wasn't the case before I adjusted the idle down to what it's supposed to be. At what temperatures does the high idle mechanism come to play? Mine's broken and I could imagine fixing it if it helps.
I'm talking outside temps at around 10-25°C (50-80°F).

If you hear an engine ping, it's pinging badly. Under normal conditions, you'll never hear it. I just hooked a scanner up to my truck to see if I could advance the timing beyond specification. Nope! A little bit of ping here and there under load is ok per owner's manual- suggests you're getting the most out of your gas.

Well, the choke pull off mechanism needs to be engaged when starting cold. You do that by stabbing the throttle about halfway before starting it. If it isn't engaging "fast idle" then you'll need to play with the hockey puck thing. That or it isn't working at all or is disengaging too soon. The puck is adjustable..

[Arquemann]

If you hear an engine ping, it's pinging badly. Under normal conditions, you'll never hear it. I just hooked a scanner up to my truck to see if I could advance the timing beyond specification. Nope! A little bit of ping here and there under load is ok per owner's manual- suggests you're getting the most out of your gas.

Well, the choke pull off mechanism needs to be engaged when starting cold. You do that by stabbing the throttle about halfway before starting it. If it isn't engaging "fast idle" then you'll need to play with the hockey puck thing. That or it isn't working at all or is disengaging too soon. The puck is adjustable..

Any ideas on how could I figure out if mine's pinging then? Obviously I haven't heard this thing ping, but I guess I don't know if it does.

My fast idle mechanism is in a box in the garage since the pull-off pot on the CFI unit is a bit busted, but I have all the parts and a new diaphragm. Just wanted to make sure it'd actually benefit me fixing it. So it does work on summer days too, when the engine is cold?

[Arquemann]

I got the choke back together, replaced the broken ear with nut and bolt, new diaphragm put in.



I've found this: https://workshop-manuals.com/ford/mu...dle/page_1265/
But I still have questions:
-In a nutshell, how do I set this up?
-The pull-off pot leaks vacuum slowly with a new diaphragm, is it supposed to?
-How do I set the puck/spring to a correct position?
-As the spring gets hot, it's supposed to lift the arm, right?

I just want it to keep the RPM slightly higher for a little bit on cold starts, not go "bwaaaaap" to 2400 RPM like it's winter in Siberia. I'll be happy with like 900 RPM for 30 seconds.
Or do I just have to experiment?

[DerekTheGreat]

It's been a cold minute since I've peeked at one of those.. Kishy would be the man to talk to here.

I do not think the pot should leak at all.

The correct position will take some fiddling. I do remember spending several days with mine, as you only want to make adjustments after starting the car when it has had a chance to cool completely. ANd yes, the spring should get the arm out of the way when warm so it no longer wants to rest at fast idle.

That's a no go on the 900 RPM at idle when cold. For whatever reason and in Ford's infinite wisdom, these do not richen the fuel mixture when cold. That's why the idle is so high. I got away with 1900 or 2100 RPM though. You'll have to spend some time futzing with that as well. You'll know if it isn't happy, it'll start surging and even die.

[Arquemann]

That's a no go on the 900 RPM at idle when cold. For whatever reason and in Ford's infinite wisdom, these do not richen the fuel mixture when cold. That's why the idle is so high. I got away with 1900 or 2100 RPM though. You'll have to spend some time futzing with that as well. You'll know if it isn't happy, it'll start surging and even die.

Uhhhh...
Is it supposed to fast idle so fucken high to substitute a rich mixture on cold starts? Or is it just another emissions thing, to get the cats warming fast?

Basically what I do on cold starts is that I give it a bit of throttle (around 1000rpm) for a short while until the cold idle doesn't drop so low it stalls.
I kinda wanted the fast idle mechanism to do that for me. As far as I've looked at the fast idle mechanism, there's just a drop-off, either its on the fast idle or not. Not like a newer car where it gradually lowers down to normal idle speed.

[gadget73]

Its not supposed to have stupid high idle, there is a high speed screw that you can use to adjust how high it is, but exactly what conditions that is set under I'm not sure. If its not on the emissions label, it would have to be somewhere in the shop manual. I'd be very surprised if the spec is over about 1200.

The fuel mix does fatten up when cold. Thats what the ECT and ACT is for. The computer knows the engine is cold and it adds fuel to compensate. The high idle is just because cold engines also need more throttle to run at a given RPM so without it you may have stalling problems.

and yeah it doesn't have a gradual ramp down, its too mechanically primitive for that. On or off is all you get. The position of the heater just controls how long it takes before it drops. If the vacuum thing doesn't work it won't be able to lift the high idle cam out. Same if the heater doesn't heat. If the spring is busted in the heater it won't drop the cam in position. Its all a bit of a balancing act.

and I also don't think its supposed to be leaking vacuum.

[Arquemann]

Yeah I've got to tinker with it tomorrow. Gotta check the pull-off first and for setting and adjustment I think I'll just go with what feels good.

[Arquemann]

Well it would appear that I now have a functioning high idle mechanism.

The vacuum leak for the pull-off was caused by the fact that the sealing surfaces weren't flat. The backhalf of the vacuum pot rocked on the axis of the screwholes, so the metal around screwholes were basically highspots. I carefully filed both surfaces flat(ter). Someone had tried to silicone it shut at some point.

As the engine and and "choke" spring was cold, I set the hockey puck so it just barely catches the lever (from my understanding it would mean the high idle won't last as long). First I had to lube the shaft for the lever that the spring moves, so it wouldn't stick. I set the RPM set screw in maybe a couple turns away from falling out, so the high idle RPM won't go the the moon because I want it be as low as possible. I'm fucking afraid of the rpms running high without my control.

Now it engages seemingly correct when I stab the throttle on a cold engine, and it fired up nicely. I'm not exactly sure how the vacuum pull-off is supposed to play with the lever, but after having it run for a while, blipping the throttle again dropped the RPM.
Having the engine run longer, I can see the warming spring keeps lifting up the lever it's attached to.