Almost complete with TBI and 700r4 install

[MazaM]

Hi everyone, I am just about finished completing the swap but am having problems with the timing. One thing I wanted set straight is what timing degree should I be trying to set to. I started with a 350/th350 2 barrel (80 swb) but have completed installing the ecm, new dist., tbi and 700r4 (90 surb). I installed plugs the same year and gap as the burb and have tried setting timing at 0 TDC with the dist. connector unplugged. If I drive at 0 (computer advances to something >12 degrees), it doesn't feel right , kinda rough, until around third she starts to smooth out. I have tried different advances but have not found the 'sweet spot'. Am I using the correct plugs and gap?? I figured it made sense going with whatever the ecm ignition used. I will post pics with the swapped fenders and doors but I have not completed installing the hood. I want to say thanks for all the info on the board. I have found most info and suggestions using the search. Thanks for any help in advance.

[1974gmc]

I dont know the solution, but I wouldnt mind some more info on the swap... ive been considered doing the same swap. Did you use all the wiring out of another truck? I was going to but a harness and computer from a firebird.

[Russell]

I usually set my timing to about 5 degrees initial advance with TBI

Stock is 0, but a little more timing across the board isn't bad with the TBI's conservative spark tables. Esspecially if you haven't got a totally stock engine, adding a bit more timing will probally make it feel far better.

As far as the spark plugs go, use the ones that are for your heads. If you used the heads off the 90, then use the same plugs as the FI had before, but if you used the 80's heads, then use the plugs for the 80. You want them gapped to about .045" or so

Also make sure that your coolant temp sensor is reading properly, if its off and thinks it is cold out, it will choke the engine out with too much fuel.

[1badbowtie]

YEAH, Factory settings are between 4-6 degrees advanced.

[MazaM]

Here is a couple of pictures. You can see the burb in the background. I picked up the burb for $450. It had a blown engine due to overheating - both heads cracked and the block was all frozen up with rust. It did have the 700r4 with doors and fenders in excellent shape so I counldn't pass up the find. I haven't cut out the holes in the cab so the different style hinges can fit, but I clamped the hood down to keep out the rain. Overall, it was a much bigger project than anticipated but I am happy with the outcome. I have been able to run it on the highway and the tranny works fine so far. I even used the cluster from the burb - figured out all the pinouts - now I have the electronic speedometer working. It probably isn't accurate, but I did find the site on how to calibrate the DRAC module to fix that problem. I can't even imagine doing the swap without the other donor vehicle around. I'm sure it can be done, but I made numerous trips back and forth to get stuff missed the first time around and I still have more to swap - possibly captains chairs, sway bar, center console, etc....




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