All the wires have been routed and secured. ECM has been secured in the slot just behind the glove box - in same spot as the later EFI trucks. So far I have about 500 miles since completing conversion. Highway gas mileage runs about 17.7 to 18.2 MPG. In the city I get about 13MPG. Highway gas mileage used to be about 11 MPG with the Q-Jet. It took a lot of planning and work to get to this point. Thanks for dropping by, IMHO just about any 70's GM car or truck can be converted. Just plan right.
Tim Every conversion is different! What may have work in my case may not be applicable in your endeavor. However, there some basics that should know about TBI. Fuel delivery system, ECM, harness, sensors - actuators and ignition system. I'll shoot you PM with some useful links. Drop me a line if you have more questions.
Original ECM (16136965) and harness were sourced from '90 Caprice Classic with 305 / 700R4. Before firing it up I've reprogrammed EPROM to handle 350 CID in my truck. Since then I had upgraded ECM with EBL conversion which allows real time tuning without chip swapping .
Thanks, it is paying dividends now - Regular Gas is hitting $3.67/G in SoCal (04/08). With TBI I am getting about 17.5 mpg (I also have 700R4, TH350 was too tired) on a highway. Not bad for 6000lbs! With Q-Jet I used to get 12's.
Did anyone else notice that fuel pressure gauge arcing its ass off on those wires? Look at 1:56-2:05 and look at the gauge on the outside edge, there is a constant sparking and dead short and if you look closely at about 1:17 you can also see it. And don't get me wrong BUT from my knowledge and overall common sense, sparks ignite fuel, so the main fuel line having a spark on it doesn't seem like a good idea to me haha. Otherwise nice truck man :)
Any video can be subject to interpretation. What may appear as 'sparks' to one viewer the reality is rather benign. I went back to source tape and zoomed in onto fuel gauge. What looks like 'sparks' is actually a thin thread of Teflon tape used to pack threads on the fuel pressure gauge tangling in the air. Conversion was completed in 07 and 4 years later runs great. There are no sparks at FP gauge, they all are in cylinder heads!
Thanks, I still have some minor tweaks to finish. My EBL equipped ECM is capable of running hwy lean mode, but it is disabled now. Fun almost never ends! Enjoy, the ride and fuel economy.
Actually you need FP relay - the ECM checks if FP voltage is present during POST. If not ECM will set DTC. Once ECM detects that engine is turning it activates FP relay. The oil pressure switch is only a back-up to FP relay, just in case if it fails. So yes, I have Fuel Pump relay together with oil pressure switch providing power to FP. FP relay coil is powered from ECM Pin A1 -dark green/wht wire, gnd is black/wht wire.
Nice!!! I have a 85 cutlass recently took the v6 out and put in a 305 tbi from a 91 caprice. Bought a in line fuel pump but having trouble getting the pump to stay on. Did you install a relay to your pump so it would cut off after the car start? I guess it will cut off but some how the gas still have to flow thru.
@WorldMafiaHipHop Most of the time EFI to Carb swaps are done by complete morons that have no idea how EFI operates. To revert back to EFI you need to find similar donor vehicle - 90 to 92 B car (Caprice or Buick Road Master) You'll need harness, ECM distributor and possibly intake manifold. The B car uses a unique distributor - intake manifold. You'll have to ditch retrofit Fuel pump and see if the in tank FP is functional. Naturally, there are more details.
For this conversion I used Holley TBI flange intake P/N 300-49. In other conversions I've used custom 1/2" thick aluminum adapter plate. If installation calls for 700R4 - a custom TV bracket is required to maintain correct TV cable extension.
i have a crate 454 engine never been ran its built off of a 70 corvette block, its just a long block right kw and i wonder if i can find same old early 90s chevy 454 truck and take to fuel injecter system of and use it for my newly built with raceing cam 454, what will i need if its evern possable
All the wires have been routed and secured. ECM has been secured in the slot just behind the glove box - in same spot as the later EFI trucks.
So far I have about 500 miles since completing conversion. Highway gas mileage runs about 17.7 to 18.2 MPG. In the city I get about 13MPG. Highway gas mileage used to be about 11 MPG with the Q-Jet. It took a lot of planning and work to get to this point.
Thanks for dropping by, IMHO just about any 70's GM car or truck can be converted. Just plan right.
Tim
Every conversion is different! What may have work in my case may not be applicable in your endeavor. However, there some basics that should know about TBI. Fuel delivery system, ECM, harness, sensors - actuators and ignition system. I'll shoot you PM with some useful links. Drop me a line if you have more questions.
Original ECM (16136965) and harness were sourced from '90 Caprice Classic with 305 / 700R4. Before firing it up I've reprogrammed EPROM to handle 350 CID in my truck. Since then I had upgraded ECM with EBL conversion which allows real time tuning without chip swapping .
And that folks, is how a TBI should start up and run. Good job
Thanks, it is paying dividends now - Regular Gas is hitting $3.67/G in SoCal (04/08). With TBI I am getting about 17.5 mpg (I also have 700R4, TH350 was too tired) on a highway. Not bad for 6000lbs! With Q-Jet I used to get 12's.
Narrow band 4-wire O2 - used by ECM is installed on passanger side, just after header collector.
WBO (ZT-2) is installed on driver side.
Did anyone else notice that fuel pressure gauge arcing its ass off on those wires? Look at 1:56-2:05 and look at the gauge on the outside edge, there is a constant sparking and dead short and if you look closely at about 1:17 you can also see it. And don't get me wrong BUT from my knowledge and overall common sense, sparks ignite fuel, so the main fuel line having a spark on it doesn't seem like a good idea to me haha. Otherwise nice truck man :)
Any video can be subject to interpretation. What may appear as 'sparks' to one viewer the reality is rather benign. I went back to source tape and zoomed in onto fuel gauge. What looks like 'sparks' is actually a thin thread of Teflon tape used to pack threads on the fuel pressure gauge tangling in the air. Conversion was completed in 07 and 4 years later runs great. There are no sparks at FP gauge, they all are in cylinder heads!
Thanks, I still have some minor tweaks to finish. My EBL equipped ECM is capable of running hwy lean mode, but it is disabled now. Fun almost never ends!
Enjoy, the ride and fuel economy.
Actually you need FP relay - the ECM checks if FP voltage is present during POST. If not ECM will set DTC. Once ECM detects that engine is turning it activates FP relay. The oil pressure switch is only a back-up to FP relay, just in case if it fails. So yes, I have Fuel Pump relay together with oil pressure switch providing power to FP. FP relay coil is powered from ECM Pin A1 -dark green/wht wire, gnd is black/wht wire.
Well - SBC with EFI is good combo once fuel and spark is dialed in.
Exhaust is a true dual 2-1/2" with Flowmaster Delta 40's, non CAT (exempt)
wow man nice work i must say
Nice!!! I have a 85 cutlass recently took the v6 out and put in a 305 tbi from a 91 caprice. Bought a in line fuel pump but having trouble getting the pump to stay on. Did you install a relay to your pump so it would cut off after the car start? I guess it will cut off but some how the gas still have to flow thru.
Where do you put the oxygen sensor on a dual exhaust system?
@WorldMafiaHipHop Most of the time EFI to Carb swaps are done by complete morons that have no idea how EFI operates. To revert back to EFI you need to find similar donor vehicle - 90 to 92 B car (Caprice or Buick Road Master) You'll need harness, ECM distributor and possibly intake manifold. The B car uses a unique distributor - intake manifold. You'll have to ditch retrofit Fuel pump and see if the in tank FP is functional. Naturally, there are more details.
Have you got a website where i can get some info? I'm doing this on a 50 chevy with a 350.
What model of vehicle did the ECM come out of?
How do you use tbi on carb intake? adapter? if so, what kind do I buy and do I just throw it on? In need of some serious guidance. . Tia
For this conversion I used Holley TBI flange intake P/N 300-49. In other conversions I've used custom 1/2" thick aluminum adapter plate. If installation calls for 700R4 - a custom TV bracket is required to maintain correct TV cable extension.
Did you need a fuel return line?
Yes, there are actually 3 lines: Supply 3/8", return 5/16" and vapor return - 1/4"
Hey Remaster could you send me the links please.
Mark
i have a crate 454 engine never been ran its built off of a 70 corvette block, its just a long block right kw and i wonder if i can find same old early 90s chevy 454 truck and take to fuel injecter system of and use it for my newly built with raceing cam 454, what will i need if its evern possable