Quick (hopefully) TBI 350 swap in my "Jeep"

[mbryson]

Unfortunately I can't check the fuel right now, but as I recall, I think they do. You might try pulling the distributor and rotating 180*. I had mine TDC on the exhaust cycle instead of on the compression cycle and it did the trick. Not sure if you pulled it or not during this project.

I haven't pulled the distributor but that doesn't mean it's not been pulled and replaced. I did have an epiphany earlier this morning that I hadn't reconnected all of my grounding straps. I'll reconnect those and see if that works along with trying to find a missing plug in the harness that needs to be connected.

 

[Jinx]

I haven't pulled the distributor but that doesn't mean it's not been pulled and replaced. I did have an epiphany earlier this morning that I hadn't reconnected all of my grounding straps. I'll reconnect those and see if that works along with trying to find a missing plug in the harness that needs to be connected.

Lack of ground will mess up the computer too. Ask Team Fred about helping me fix a similar problem with the wiggle test to find a loose ground...

 

[Hickey]

Check fuses, too. I forgot to attach a ground on a motor swap once and it blew a fuse in the ignition circuit.

 

[mbryson]

There was one grounding strap connected but I think I've still got a few that need to be connected

 

[mbryson]

http://www.gmc4x4.com/topic/1035-1991-57l-bored-tbi-upgrade-write-up-warning-lots-of-pics/

Good writeup for anyone referencing.

 

[mbryson]

http://www.gmc4x4.com/topic/1035-1991-57l-bored-tbi-upgrade-write-up-warning-lots-of-pics/

Good writeup for anyone referencing.

http://www.73-87chevytrucks.com/techinfo/TroubleshootingTBISystems.pdf

Good step by step troubleshooting guide?

I am able to have the engine run for a few seconds if I pour gas down the TBI throat. Need to troubleshoot why I don’t have injectors spraying. I like the troubleshooting steps in the attached document

 

[Bart]

I have a full TBI package I got with my motor if you want to test some things.

 

[mbryson]

I may take you up on that Bart. Spent about 2-3 hours figuring out I have electrical signal to my injectors. Just no injectors firing. Just rebuilt the throttle body and have a pressure regulator leak. I'll tear it down again, possibly tomorrow. Tempted to stop by pick and pull tomorrow and dig up another throttle body.

 

[Bart]

I have one sitting in a box, but I realize proximity is a factor. If I weren't up to my eyeballs in my swap I'd meet you somewhere. Good luck. I hope to have mine running by Saturday night.

 

[mbryson]

I have one sitting in a box, but I realize proximity is a factor. If I weren't up to my eyeballs in my swap I'd meet you somewhere. Good luck. I hope to have mine running by Saturday night.

It'd be worth the drive if I can get this thing going. I have a 2nd one from my donor I've been stealing parts off of. I might need to make that one my primary?

 

[BCGPER]

It'd be worth the drive if I can get this thing going. I have a 2nd one from my donor I've been stealing parts off of. I might need to make that one my primary?

I have to be in Arm Saturday morning, I could get it half way to ya.

 

[mbryson]

I have to be in Arm Saturday morning, I could get it half way to ya.

I hope to have time again to work on it tomorrow night? To much work tonight

 

[mbryson]

Got a little time tonight. Have the TBI back together. With the key on and if you jump the injector terminals with positive/neg, it will squirt fuel. If I crank to start after that, it will fire for a few revolutions. Thought I had something squirrelly in the distributor. Swapped distributors with my old engine.

No dice.

Checked to make sure engine would still run, I don't swap a lot of distributors these days, and it'll run as long as I give it fuel.

So.... electrical issue for sure. I haven't found the issue but have found something interesting that likely is the issue. The left side of my fuse box ('89 Suburban) has horn, headlights, tail lights, and a 2nd ECM fuse. No power to any of that stuff....

I'll be trying to figure that out (how I'd kill that swapping an engine, I have no idea?

 

[Bart]

I'm guessing there's a wire hanging somewhere. I'm sure you've looked at it a million times.

 

[Pile of parts]

I wish I could remember a little better from doing mine. There is definitely a signal for start up that sends an initial squirt for start up and a separate signal to keep it running. I had the same issue when I installed mine. It would fire and continue to run if I fed it fuel. I think you're on to it with the second ecm fuse. When I rewired the chassis last spring I had to figure out the two separate circuits and their relation to the key position. Unfortunately, without going back and looking at it, I can't remember. I try to suppress those wiring/electrical memories.

 

[mbryson]

I wish I could remember a little better from doing mine. There is definitely a signal for start up that sends an initial squirt for start up and a separate signal to keep it running. I had the same issue when I installed mine. It would fire and continue to run if I fed it fuel. I think you're on to it with the second ecm fuse. When I rewired the chassis last spring I had to figure out the two separate circuits and their relation to the key position. Unfortunately, without going back and looking at it, I can't remember. I try to suppress those wiring/electrical memories.

It should be a pretty simple fix but I haven’t hit on it yet. Bonus (I think?) that I rebuilt my throttle body and now know a few ‘tricks’ to get the injectors to fire in a pinch. I started pulling the engine harness apart again last night (I did some tidying while I had a chance-harness is still in good shape but the loom stuff was a disaster after 30 years). I have to have wrapped a single wire up into something that needs to be plugged in somewhere.

Fusible link is good, “pink” wire is hot (that’s the sacred cow for swaps—mines less of a swap and more of a Suburban being that I have all GM wiring/column) etc. I’m sure there is something

 

[mbryson]

Just found something that might be it. (getting the oil changed in the G8 this morning and thought I'd dig up a wiring harness diagram for the "Jeep") I have a stray POWERED wire that I've been trying to figure out what it's for (kind of exactly what I'm looking for but I thought it went to my Taurus fan). It MAY go to the alternator? (see highlights on page 11 of attachment) If that lights up the left side of my fuse panel, I think I'm in business? I'm playing rear axle swap on my MJ this morning (swapping a D35 for a D44 so it's kind of worth the work?) but hope to get back to the "Jeep" pdq after that?

The stray wire runs directly off the positive terminal of the battery and has about the right size connector to be mounted to the back of the alternator. I'm hoping I found the issue while I'm sitting. Again, time will tell. Sounds to easy to be the fix but the longer I think about it, the more I am SURE that wire doesn't go to my Taurus fan or other mbryson added crap to make the swap work.

(pdf stolen from http://www.73-87chevytrucks.com/techinfo/7387CKMans/Wiring/ST_350_89_1989_GM_RV-P_Light_Trucks.pdf - mucho thanks to them for hosting the digital version of that)

 

[mbryson]

Well, the mystery powered wire isn't necessarily the alternator wire. It isn't quite a banjo string but close and I'm fairly confident that's not the solution. (I did try it and didn't get the left bank of my fuse panel lit up...) That's still the issue. Need to figure out why that's not got power and I think I'm in good shape?

Latest plan: I have the harness from the donor engine. It’s not an exact match but is 95% or so. Only differences I know of are actual connectors but I’m sure there are a few things? Anyway, my thought is to spread the harness out in the floor next to the Jeep, then verify each connection that’s connected in the Jeep, er Suburban. Hopefully I run across something that’s not connected as I haven’t found anything suspect yet.

 

[moab_cj5]

Well, the mystery powered wire isn't necessarily the alternator wire. It isn't quite a banjo string but close and I'm fairly confident that's not the solution. (I did try it and didn't get the left bank of my fuse panel lit up...) That's still the issue. Need to figure out why that's not got power and I think I'm in good shape?

Latest plan: I have the harness from the donor engine. It’s not an exact match but is 95% or so. Only differences I know of are actual connectors but I’m sure there are a few things? Anyway, my thought is to spread the harness out in the floor next to the Jeep, then verify each connection that’s connected in the Jeep, er Suburban. Hopefully I run across something that’s not connected as I haven’t found anything suspect yet.

Good Luck! You have WAY more patience than I do...

 

[mbryson]

The mystery wire IS the alternator wire.




It’s cold out here. I won. I’ll time it and put this pile back together soon.