My '85 MGM, "Maisa"

[gadget73]

if you use a carb from an AOD car, it should just bolt up. I think that limits you to a 2bbl from an early 80s model though. I don't believe the AOD was ever married to anything that had a 4bbl, and even if it was it would probably be some dinky bullshit emissions carb that you wouldn't want anyway.

and the Lokar cable is pretty shitty IMO so its not like there are many good options here.

[Arquemann]

So I think I'll post my list now

The problem is a jerky / bucking decel, jerky when cruising at very low throttle and a rich idle. Idle bucks on some days.


Basics:
- Got compression
- New timing set, cam set 4° advanced, base timing 10° BTDC
- No vacuum leaks (except for small ones in throttle kicker and HVAC controls)
- New PCV
- Wiring seems good, grounds checked and no obvious corrosion anywhere
- EGR seems to work correctly and Thermactor is disabled

Ignition:
- New plugs, wires, cap, rotor, coil, reman distributor and Motorcraft TFI module

Fuel:
- New injectors, pressure regulator, fuel filter
- Fuel pressure checked good
- No dirt or water in fuel/tank
- I use regular gas E95 (equivalent to US 91) Running premium doesn't make any difference.

Electrical:
- New TPS, O2 sensor, EGR position sensor, ECM
- MAP, coolant temp, intake air temp sensors checked good
- New alternator and used voltage regulator (for whatever that's worth)


So whadda ya say, time to throw in the towel? I wanted to like CFI, but in return it's just been a total bitch from the very beginning.
Please do make suggestions if you fine folks still come up with something to check...

[sly]

Verify spark wires are fully seated. I've had them unseat after initial install and sit just barely making contact to the plug. Pushed back on while the engine was warm and then stayed put.

But yeah... can't think of anything other than a general check to make sure everything is actually connected. Also, the major wire connectors near the brake booster may need to have them disconnected and have the female connector squeezed together a bit to make good contact. Not sure if the CFI cars had the same wire bundles as the SEFI cars, but I think there is a bundle there. Basically check the wires from the coil/dizzy/injectors back to the modules and make sure all the connectors are solid.

[matth825]

My '85 MGM, "Maisa"

That’s a pretty creative solution with reworking the rod. The rod would be preferable over any type of cable but that’s beyond my skill level.

I did some digging around last night and found this cable:

https://www.googleadservices.com/pag...A&dct=1&adurl=

The throttle end looks like it would work with this bracket:

https://www.googleadservices.com/pag...o&dct=1&adurl=

Add a sonnax TV corrector arm on a Holley carb and it looks like that end would be covered.

The Achilles heel of this plan would seem to be finding the cable capable bracket that goes on the trans from a junkyard panther. I’ll have to start hunting for one.

I wish I had direction to give you with your CFI but I don’t. If mine were as temperamental as yours it would be getting tossed for carb or an aftermarket Holley TBI setup. I went down the rabbit hole of looking at those last night. They share the same throttle linkages/footprint as a Holley 4BBL so if my cable idea pans this would be an option.

Sent from my iPhone using Tapatalk

[Arquemann]

@sly I've gone through pretty much every connector in the engine bay a couple times atleast. Didn't hurt (except my knuckles a bit) to check again, but didn't find anything either. Don't really know what you mean by squeezing the female connector sides, not gonna de-pin the entire ECM connector for that. I've had the wiring loom opened up from the dizzy all the way to the ECM at one point. Plug wires are nice and snug.
Don't know if any of this would've caused the issues I've mentioned to only really happen on closed throttle...

@matth825 Your links are invisible btw.
I dunno, a cable is a cable, atleast the lokar piece is mostly metal. The one you linked looks to be mostly plastic. TCI makes a cable that's supposedly all metal, but its even more expensive than the Lokar one.
Not exactly sure a stock trans linkage from a JY will surely work with the linked "OEM style" cable, need to make sure it has the same pivot length as the Lokar and others, that way it'll surely be correct with the carb arm pivot length.
I'd rather buy the whole Lokar kit vs buying just the cable and buying/finding suitable brackets for both ends and the corrector piece... Honestly I don't get the hate the Lokar piece gets, surely it works?


I'm not trying to avoid the cable because I don't want a cable. I'm avoiding it due to cost... I'm broke as fuck and kinda cheap too.
To me the Autolite 2150 is a really attractive option due to the low cost. I wouldn't have to buy anything other than the carb for trans hookups.

VS going 4bbl:
- Intake
- Carb
- Cable
- Corrector bracket

VS going with some other 2bbl carb:
- Carb
- Cable
- Corrector bracket

And I'm in Finland, so there's no sbf 4bbl intakes and dirt-cheap carbs just lying around in neighbors attics and sheds. I can find one e-choke 4bbl for sale for 200€, Holley 450 cfm, condition unknown.
Then I'd need a 4bbl intake, one Edel performer currently for sale used, 200€. Then slap about 200€ more for the misc. cables and brackets. And then I still need an ignition system to even get the car running.
A Rockauto reman 2150 is about 250€ plus shipping and VAT.

Only thing about the 2150 I don't really like is the (lack of) performance. Wiki mentions two different venturi sizes, I'd certainly like the bigger one for some headroom, but I have no idea what vehicle I should pick in RockAuto to find a 1,21 venturi unit with the AOD hookups. If I can get like up to 250 crank horsepower with the 2150, it's absolutely fine.

Of course I'd certainly appreciate if one of you americans can find me a dirt cheap 500cfm 2bbl or 4bbl + intake combo and put it in a box coming this way.

[Arquemann]

Oh yeah here's the couple pics that the finnish guy sent. 351W, holley 4bbl, rod from a 302, so it was kinda short. The corrector arm piece used is apparently just a piece of "just something from something". Trans bracket was also cut and rewelded.

[matth825]

My '85 MGM, "Maisa"

Thanks for those pics. He did a good job with that.

Hopefully the links are visible and working now. All of the hate the Lokar cable gets is due to the way it attaches down at the trans. It’s kind of crummy. The bracket and arm that Ford used with the cable just looks more robust and durable to me. I’m willing to give their setup a try with that cable.




Sent from my iPhone using Tapatalk

[sly]

No need to de-pin. Just get a pair of needle nose and give the female connectors a squeeze (just enough for a little flex, not enough to squish). Sometimes just reseating the connectors does the trick as there could be oxidation that gets scraped off. Sometimes it's just the electronics being stupid.

[Arquemann]

No need to de-pin. Just get a pair of needle nose and give the female connectors a squeeze (just enough for a little flex, not enough to squish). Sometimes just reseating the connectors does the trick as there could be oxidation that gets scraped off. Sometimes it's just the electronics being stupid.

Yeah I still have no idea what connectors you mean, must be SEFI stuff. There's no chance to do anything like that to the ECM 60-pin connector, and the only other connector in that corner is a 6-pin bullet pin connector:

Looks a bit filthy, alot of the connectors in this car have dielectric grease, but it doesn't seem too old.
A couple similar bullet pin connectors nearby, I don't think these are the kind that I could go squeezing with pliers.
The ECM connector is clean as can be and the ECM is new.

[sly]

Yeah, I'm out of ideas.

[Arquemann]

I have a lead, kinda.

I've ran errands for a couple days with the O2 sensor unplugged as it seemed to smooth out the idle. Yesterday I had plugged it back in as went to get my friends for a cruise night that was ~45 minutes away, and holy shit the decel jerkiness was SO BAD.
Ended up unplugging the sensor at the friends place and we drove the whole night without it.
Without the O2 sensor, the jerky decel isn't too bad, but not something I'd just tolerate. Also it's probably not the best for the engine to run long term without an O2.

Though the O2 sensor is new, and I do remember checking the voltage it gives last summer. Probably won't hurt to check again.
I do not have lean/rich codes either.


Is EEC-IV modern enough to have short and long term fuel trims? That would explain why the jerkiness was the worst its been after plugging it back in after a while. Though without an O2, surely the engine would work from set base parameters...

[Arquemann]

Well, my suspicions were correct, the O2 sensor seems to be bad. Or something else...
As the car was warming up, it was showing about 600-700mV (a bit rich), and then I took the car for a lap to warm things up.
With the engine hot, idling in park the sensor was showing about 900-920mV...
The readings aren't "stuck" either, the readings do respond to throttle and I can see somewhat sensible values by blipping the throttle.

It seems on monday I'll be picking up an O2 sensor along with the new front rotors and wheel seals.

With a new sensor things will either improve or go nowhere. I am a bit afraid of the latter, as the hot idle AFR didn't change too much with the sensor plugged in or not. With some throttle input, the readings seemed a bit more reasonable with the O2 disconnected.
If a new O2 sensor won't fix the issues I'm having, the fate of the CFI might be sealed.

Also, SOUNDS! It's not very loud at all, the recording just makes it seem so.
(sound file) https://drive.google.com/file/d/1xI2...ew?usp=sharing
I haven't had the chance to record it before, since I don't hear it everytime, and it usually goes away pretty quickly after starting. Sometimes I hear it faintly with a warm engine aswell.

[gadget73]

there should be an engine sensor ground somewhere on those motors. I don't know where exactly it lives, may be bolted to the rear of the head, but verify its still there otherwise the ECM will get bad info from the sensors. If the air and coolant sensor values are skewed from a missing ground, it screws with the fuel mixture.

[Arquemann]

there should be an engine sensor ground somewhere on those motors. I don't know where exactly it lives, may be bolted to the rear of the head, but verify its still there otherwise the ECM will get bad info from the sensors. If the air and coolant sensor values are skewed from a missing ground, it screws with the fuel mixture.

Ground in the back of the head is intact and cleaned. Probably hasn't disappeared since last summer.

[Arquemann]

Well, the new O2 sensor didn't seem to help. Hot idle shows about 700-750mV. With throttle input, the readings get just as confusing. Idle smells like gas just as before.
Most importantly, the jerky decel still exists the same.

Now what? Start gathering parts for a carb setup?
I am quite done with CFI at this point.