can a 1228746 ecm in a 91 rs be replaced with a 1227747 ecm from a 90 chevy p/u? they have the same pinouts, and i have read where guys do this swap. do you change wiring harness also? is there something different? desperatly need help! thanks

 

Plug & play. Although you will lose the use of the IAT. The AIR system most likely won't work correctly either. I don't believe that the trucks used a 2-solenoid AIR system.

RBob.

 

trying to save a little money. could the 1227747 wiring harness be used or would it be the same as the car harness? they have the same pinouts, but could something be dif? thanks

 

No need to change the harness. Just be sure to get an ECM from an 8-cylinder vehicle.

RBob.

 

bought the ecm new, had a custom chip made for my set up. the custom chip runs the car, but very rich and has a bad dead spot. the stock ecm and chip runs the car great except for the idle because of the cam. no trouble codes on either one. trying to get the guy to check his chip for a defect but so far no luck with that

 

double checked the pinouts, they are basicly the same except for a couple of wires that i took out, but some of the wires are different colors than what the diagram shows. i dont have the colors in the harness that it calls for. could that be a problem?

 

hi i got a sort of similar question but kinda hesitant to ask because its ---different.
I want to run a 292 truck engine with two 2.5 cavelier throttle bodies on a modified offenhauser intake. The 4.3 6 cyl pickup ecu would be right for the cylinder count---- but the 305 powered pickup would be more right for engine requirements--should I go with a 730 pickup ecu and go in and change the cylinder file --would this be the easiest? how would someone modify a stock injection harness thats for a singge throttlebody--like the v8 pickup----To controll TWO throttlebody injection units?

oh yea --anyone wondering--- the planets name is Zyvax.

 

The '7730 wasn't installed in truck AFAIK.

Since the Cavalier TBs are single bbl units, you can simply split the injector wiring between the two throttle bodies. Use one TPS, and two IACs.

This would be very similar to my Crossfire conversion on my Grandfather's pick up, using a 16197427 PCM.

 

Offy intake is huge. 292 cid is rather small. I expect tuning to be well a challenge to say the least. What to do on linkage? Some ran the crossfire TB's and its linkage on a plate I recall.

 

Nope the Clifford has huge cavernous runners, the offy is pretty much like a stock 1 barrel chevy 6 intake, cept 2 pot.
im modifying it to run twin holley 94's for a backup/limp home plan and the throttle bodies will have to fit with adapter plates if i have to.
anyone know what cars with the 305 had a 730?

Seems 6 shooter is right the 730 didn't come in the pickup---DAMN.
The 89 cavelier throttlebodies have cool cast aluminum hats that clamp over the tops with v bands--perfect for boosted apps-- I want to run code 59 and use an old rajay or holset hx30 I have on the old monster.

 

Why do you want to run the '7730?

You can use any '7730 from any application, they are all the same between all applications. What differs is the MEMCAL. You can use a V6 MEMCAL with a V8, by adding a jumper across two particular pins, and loading a correct bin to the PROM or using a MEMCAL adapter to use a new EPROM. This modification is for port injection, TBI is different, and not sure if the calibration for such has been explored.

The dual TBI runs well on a 16197427 PCM, from the '93 to '95 full size GM trucks.

I don't know of any running set-ups using TBI and $59, though I have thought about what it might take to make it work.

 

Thanks for the input 6shooter, your last sentence addressed my next question.
Main reason I want to use the 730 is knowing you can run code 59 on a 727 or 730

i wonder if its possible to run 59 on the 427--if its possible to operate throttlebodies with a boosted situation, seems fesable.

The reason im doing the TBI injection is because of the siamesed ports the chevy 6 cyl has--port efi is not really doable even if i wanted to have bosses welded in at the intake flanges. Also something else that seems apparant--The TBI computer would be twice as dumb as a port efi one--it really wouldn't have to know the # of cylinders since its injecting just at certain cycle points.

 

No $59 will not run on the '7427.

Just FWIW, the '74727 has more processing power than the '7730/'7749/'7727. Just because it runs TBI, doesn't mean that it is any less "smart."

Once you get into the code and see how similar and different each code is, you'll understand more about why it's the code that matters as far as how "smart" a system is, more than what the actual ECM is.

There are settings in $59 to use TBI, but AFAIK are untested. Also the MEMCALs used in those ECMs were for port injection from what I have seen, and there is a hardware side that needs to match for everything to work right.

This type of stuff should probably be addressed on the $59 forum though.

 

dynamicefi supports boost. Also supports multiple TB's and port fuel as well. check this out: dynamicefi.com