- Joined
- Mar 17, 2005
- Location
- N. N. Raleigh, NC
TBI Swap to Small Block Chevy - It runs
Well alot has been done in the last few weeks (or has it been months?) I plumed the fuel lines to the YJ tank and used the stock 4cyl EFI pump the GM TBI only needs 9-15 ish PSI to run properly and the 4cyl elec. pumps are in that range...
I had some problems with my wiring. I had thought I wired my ECM to the correct power lead off the switch but I didn't I was dropping power while cranking. (kinda need the ECM when your trying to start things up) Commone mistake from what i read. Traced my switch out and will be fixing that this coming week. I jumpered the ECM for now..
With that problem solved it STILL wasnt running. Im like what gives !! I had spark and thought i had enough fuel.. Maybe it was the wiring or some other problems from the swap... uggg.. I used a test light. (aka a former side marker lamp with some aligator clips) and cliped to each injector wire.. And tried cranking... To my relief each one pulsed as you'd expect..
But the injectors wernt doing anything.. Not clicking or anything.. So i immediatly tore the TBI off and tor it apart... of course all the gaskets crumbled never to be used again.. Luckily the parts store have a kit in stock (only $55) BUT it was complete and included a Base gasket i already spent $12 on seperatly.. SO it wasnt to bad.. I figured that even IF i could fix it. Id need the gaskets anyway to install any new or used parts.
The injectors were very 'dusty' and it was obviouse that had been sitting for a while... So with them removed I tied some wires to the inputs and briefly hit em with 12v (note this is safe as the ECM uses 12v just in very short bursts). One labord for the first click then clicked normally... The other didnt click so after a few tries i promplty smacked it on the bench and tried again.. All fixed
I then put the TBI unit back together and used some vasoline on the gaskets to help keep them from sticking.
At this point ill add that I probably could have done the 12v and smacking stuff with the injectors still mounted and not have had to buy anything else. The kit did include the pressure regulator diaphram which i installed as the old one was very well worn, but may have worked (or not) Other advantage is I now know how to do this and could easily do this trail side or in camp under less than ideal conditions..
I hooked up the gas lines and primed the pump and hit the switch bam she fired right up !!! SWEET !!!! Its running real rich (this was expected) with the carb cam shaft in it but ill be starting some tuning this next week after i do some data logging....
Well alot has been done in the last few weeks (or has it been months?) I plumed the fuel lines to the YJ tank and used the stock 4cyl EFI pump the GM TBI only needs 9-15 ish PSI to run properly and the 4cyl elec. pumps are in that range...
I had some problems with my wiring. I had thought I wired my ECM to the correct power lead off the switch but I didn't I was dropping power while cranking. (kinda need the ECM when your trying to start things up) Commone mistake from what i read. Traced my switch out and will be fixing that this coming week. I jumpered the ECM for now..
With that problem solved it STILL wasnt running. Im like what gives !! I had spark and thought i had enough fuel.. Maybe it was the wiring or some other problems from the swap... uggg.. I used a test light. (aka a former side marker lamp with some aligator clips) and cliped to each injector wire.. And tried cranking... To my relief each one pulsed as you'd expect..
But the injectors wernt doing anything.. Not clicking or anything.. So i immediatly tore the TBI off and tor it apart... of course all the gaskets crumbled never to be used again.. Luckily the parts store have a kit in stock (only $55) BUT it was complete and included a Base gasket i already spent $12 on seperatly.. SO it wasnt to bad.. I figured that even IF i could fix it. Id need the gaskets anyway to install any new or used parts.
The injectors were very 'dusty' and it was obviouse that had been sitting for a while... So with them removed I tied some wires to the inputs and briefly hit em with 12v (note this is safe as the ECM uses 12v just in very short bursts). One labord for the first click then clicked normally... The other didnt click so after a few tries i promplty smacked it on the bench and tried again.. All fixed
I then put the TBI unit back together and used some vasoline on the gaskets to help keep them from sticking. At this point ill add that I probably could have done the 12v and smacking stuff with the injectors still mounted and not have had to buy anything else. The kit did include the pressure regulator diaphram which i installed as the old one was very well worn, but may have worked (or not) Other advantage is I now know how to do this and could easily do this trail side or in camp under less than ideal conditions..
I hooked up the gas lines and primed the pump and hit the switch bam she fired right up !!! SWEET !!!! Its running real rich (this was expected) with the carb cam shaft in it but ill be starting some tuning this next week after i do some data logging....
