Mazda B2200 TBI Conversion?

[JCampbell]

Anybody have any experiece adapting TBI from a GM 4cyl, such as an S10 or Cavalier to a non-GM 4cyl?

My son recently bought a super clean 90 Mazda B2200 for his first truck. They are cool little trucks, and I owned a few as a teenager and early 20something. The rush of nostalgia is fun, but I'm starting to have nighmarish flashbacks of the finicky electronic carb that these little rigs came with.

It's been 20 years since I messed with these trucks and a lot has changed since then. I've been doing some reading and it seems like FE3 (2.0l Kia Sportage) swaps, 1.8l Miata swaps, and rotory engine swaps are all fairly common. Even the old Weber 32/36 is still a popular mod.

I got to thinking, how hard would it be to adapt GM TBI to the venerable K3 2.2l Mazda? Fuel delivery and management seems like it would be relatively straightforward, but what about the timing aspect? Mod a GM 4 banger distributor to a Mazda dist shaft, or run a fuel only swap and rely on the factory Mazda vacuum-operated advance to handle ignition and timing?

Curious to see what others have done or learned throughout the years.

[dave w]

Some of the early non-GM EFI conversions were fuel only.

GM TBI can be triggered by using a MSD 6A Ignition Control Box (square wave Tachometer signal) https://www.ebay.com/p/1222074102?iid=362801678302&chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=362801678302&targetid=475515326381&device=c&mktype=pla&googleloc=9033615&poi=&campaignid=6469981122&mkgroupid=79220336802&rlsatarget=pla-475515326381&abcId=1141176&merchantid=8026134&gclid=EAIaIQobChMIhcTEkNfw5gIVhMpkCh0z4wiHEAQYBSAB EgIVK_D_BwE

Many of the Mid 80's GM 2.5 Liter / 151 cubic inch 4 cylinder engines were single barrel Throttle Bodies. https://www.ebay.com/itm/Throttle-Body-85-86-Grand-Am-2-5-ID-17085068/312896488237?hash=item48da15832d:g:rK4AAOSwwfFd-jXW

dave w

[steveo]

if you dont need to tune it and you just want injection without a ton of trouble, there is a fuel injected 2.2 that mazda made in later trucks. at one point i had both engines and they were damn similar

i wouldn’t put much effort into that thing as it struggles to make 100hp on a good day

the stock carb runs surprisingly well with everything unhooked and all vacuum ports capped off if you want to try that.

my truck ended up getting the weber carb and i ripped like 50 pounds of hoses, wiring, and sensors crap out of that engine bay

[JCampbell]

Some of the early non-GM EFI conversions were fuel only.

GM TBI can be triggered by using a MSD 6A Ignition Control Box (square wave Tachometer signal)

Many of the Mid 80's GM 2.5 Liter / 151 cubic inch 4 cylinder engines were single barrel Throttle Bodies.

dave w

Thanks Dave. I think I can make this work. The coolant temp sensor might be sorta tricky. The GM unit being 3/8” NPT, whereas the Mazda uses M12x1.5 thread size. I could run a stock Mazda CTS if it operates under the same general parameters as the GM unit.

I’d love to explore this with you further one of these days.

[JCampbell]

if you dont need to tune it and you just want injection without a ton of trouble, there is a fuel injected 2.2 that mazda made in later trucks. at one point i had both engines and they were damn similar

i wouldn’t put much effort into that thing as it struggles to make 100hp on a good day


I’m aware of the 2.2l EFI engines. There are a few reasons I’m not considering that conversion. One being Mazda B-series EFI parts are hard to come by in the JY and relatively expensive to buy new. Secondly, the aftermarket support for GM TBI exists…Mazda, not as much. Third, I’m familiar and comfortable with GM TBI.

Yes, at 85 HP, the 2.2l is not a massive powerhouse. This conversion is simply for improved reliability and drivability. I’m not a giant fan of carbs in general, and feedback carbs I find particularly annoying. That being said, I did consider a Weber 32/36…and it’s still a possibility…but I’d much rather run EFI.

[steveo]

definitely go for it then!

if you score a 2.2 efi distributor that might make a better trigger? and run proper ecm controlled spark

things like the coolant temp sensor will be the least of your issues; maybe you can grab an npt brass pipe plug, then drill and tap that to make an adapter

[JCampbell]

You know...I didnt even consider adapting the stock FI Mazda distributor.

Good call.

[dave w]

Maybe the original Mazda distributor (for a carburetor) has a magnetic pickup to trigger a GM Ignition Module?

See attached pic.

dave w

[ony]

is this similar to what eagle mark was working on?

[JCampbell]

Not sure who that is. Here's the link:

http://www.mazdatrucking.com/forum/showthread.php/17207-93-B2200-EFI-Conversion

[JCampbell]

Looking into the resistance values of the Mazda vs. GM CTS. They look close on the upper end, but get a little further apart down low. Anybody have any thoughts/comments on the compatibility of these values?
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[dave w]

The mazdatrucking.com link is a Fuel Only control. The TBI computer does not control spark advance.

Using the GM Ignition Module allows the GM computer to control spark advance.

Good - carburetor
Better - TBI Fuel Only
Best - 100% TBI functionality ( computer controlled fuel and spark advance):jfj:

dave w

[JCampbell]

Maybe the original Mazda distributor (for a carburetor) has a magnetic pickup to trigger a GM Ignition Module?

This looks promising. Apparently the earlier b2000s (2.0l) have a magnetic pickup in the distributor.

https://www.streetsource.com/threads/35211/mazda-22l-trouble-installing-6a-msd-box-89-b22

Dave...I'm a little foggy in this area. Does this mean I could modify the early Mazda dist, bypass the vac advance and run full TBI ECM timing control? If so, how? Because that would be awesome.

[dave w]

I'm not familiar with Mazda's.

The functional description is as follows: the magnetic pickup will make an Alternating Current (AC) signal when the distributor shaft starts spinning. The AC signal is very low voltage, but the AC frequency will change as the distributor shafts spins faster and faster. The GM Ignition Module converts the AC signal from the pickup coil into a square wave that the TBI computer reads as a distributor reference pulse (aka Engine RPM).

The GM Ignition Module is very universal, it will accept magnetic pickup AC signals from all automotive pickup coils manufactured / imported to the United States after 1975, including the pickup coils manufactured by Mazda after 1975.

For an EFI conversion, a distributor with a vacuum advance will need the vacuum advance mechanism welded.

dave w

[mecanicus]

@Dave w
"For an EFI conversion, a distributor with a vacuum advance will need the vacuum advance mechanism welded."
I guess you mean the flywheel (centrifugual) advance mechanism.

[Fast355]

@Dave w
"For an EFI conversion, a distributor with a vacuum advance will need the vacuum advance mechanism welded."
I guess you mean the flywheel (centrifugual) advance mechanism.

BOTH mechanisms will need to be deleted and disabled. Easiest just to weld them in the static fully retarded locations.

[tayto]

do a Google search for Toyota gm efi conversion. he used the pickup out of a stock Toyota distributor and remotely mounted a GM ignition module on an aluminum heatsink. if distributor has mechanical advance you will have to remove and weld @ 0*.

[JCampbell]

do a Google search for Toyota gm efi conversion. he used the pickup out of a stock Toyota distributor and remotely mounted a GM ignition module on an aluminum heatsink. if distributor has mechanical advance you will have to remove and weld @ 0*.

This link, correct?

https://www.pirate4x4.com/forum/toyota-truck-4runner/895975-22r-tbi.html

"Also, the GM ignition module needed a heat sink, hence the small aluminum plate behind it. The 22RE distributor connects to the ignition module in a specfic way: distributor red wire -> P terminal on module. distributor white wire -> N terminal on module. If you get them backwards, you won't get a proper signal to the ECM and it will run like poop."

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[tayto]

yes that's it, hard to believe i remembered that from over 9 years ago. hopefully that gives you some ideas....

[JCampbell]

The 2.2l EFI distributor is set up for electronic ignition with "Hall effect". That is the reluctor ring/magnetic pickup, correct?

I should be able to use the EFI dist and not have to fool with the vac advance in the carb dist, correct?

AIP Electronics Complete Premium Electronic Ignition Distributor Compatible Replacement For 1990-1993 Mazda B2200 2.2L With Hall Effect T2T53071A MZ50 Oem Fit DT2T530 https://www.amazon.com/dp/B01DPXFLK2/ref=cm_sw_r_cp_apa_i_JCagEbZZY564X

[tayto]

you will need to use a dist (or modify) with a magnetic pickup. i dont believe the gm module will work with hall effect. your carb'd distributor should have magnetic pickup? if so can remove vac can and weights and weld so ECU can control advance

[tayto]

go on rockauto looks like you can order magnetic pickup and reluctor for a carb'd setup. weather it wil bolt into your EFI dist, i am not sure.

[JCampbell]

Got it. Thanks.

[dave w]

The 2.2l EFI distributor is set up for electronic ignition with "Hall effect". That is the reluctor ring/magnetic pickup, correct?

I should be able to use the EFI dist and not have to fool with the vac advance in the carb dist, correct?

AIP Electronics Complete Premium Electronic Ignition Distributor Compatible Replacement For 1990-1993 Mazda B2200 2.2L With Hall Effect T2T53071A MZ50 Oem Fit DT2T530 https://www.amazon.com/dp/B01DPXFLK2/ref=cm_sw_r_cp_apa_i_JCagEbZZY564X

Hall Effect should work, but a bench test for verification would be a good plan.

dave w

[tayto]

AFAIK a hall effect generates a DC square wave output vs a magnetic pickup which generates an AC signal, but I have never verified with a scope.

[JCampbell]

Does anybody know offhand what the CFM rating is on the 2.5 TB?

[dave w]

Does anybody know offhand what the CFM rating is on the 2.5 TB?

I'm going to guess about 270 CFM, based on the fact that a two barrel 5.7 throttle body is 535 CFM.

dave w

[dave w]

AFAIK a hall effect generates a DC square wave output vs a magnetic pickup which generates an AC signal, but I have never verified with a scope.


Good point. The question is the difference between a pulsed DC signal vs. square wave DC signal? The GM Ignition module will reshape a pulsed DC signal to a square wave DC signal.

https://en.wikipedia.org/wiki/Pulsed_DC

dave w

[THEFERMANATOR]

Have you considered something like running the GM single barrel tbi unit, then pick up a microsquirt controller to run it. They've gotten pretty cheap for the basic microsquirt controller, you can program in custom sensor values, and select whatever timing pickup style you want. If I hadn't been doing a 4l80e swap on the last tbi I did, it would have gotten a microsquirt instead if a 7427.

[JCampbell]

Have you considered something like running the GM single barrel tbi unit, then pick up a microsquirt controller to run it.

I looked into it a little this weekend after I saw your post. The actual, physical size of the controller is appealing. The stock Mazda ECU sits in the passenger side kick panel, and I wasn’t sure I’d be able to fit a GM ECU.

I’m open to it. How complicated is it to set up and run?

[JCampbell]

Picked up the single barrel TB off eBay and found a 2.0l distributor this weekend at the local Pick N Pull. Going to start piecing parts together and see what happens.

[THEFERMANATOR]

I looked into it a little this weekend after I saw your post. The actual, physical size of the controller is appealing. The stock Mazda ECU sits in the passenger side kick panel, and I wasn’t sure I’d be able to fit a GM ECU.

I’m open to it. How complicated is it to set up and run?
I haven't run one myself, I just looked into it before we decided on a 7427 to run the trans. So far they have really good feedback. It's supposed to be pretty similar to the megasquirt 2, just without all the injector and ignition drivers(only has 4 instead of 8). For DIY stuff they seem very popular because of there small size.

[JCampbell]

TB came yesterday.

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