Vortec -> Carb now -> TBI

[EagleMark]

I've heard about it, sure I've seen and read it, pretty sure I had it on my old laptop that had a cup of coffee go through keybord and out USB ports. But I can't remember where, DIY or early ThirdGen? Just the obvious keywords? I searched pretty hard when we were working on the knock sensor, ESC and Memcal stuff.

[CDeeZ]

On my Nissan 2.8L I6 (Using Delco EFI), I used a 45* brass "street elbow." I threaded the elbow in place of where I had the knock sensor, then threaded the knock sensor into it.

Were you experiencing false knock?

[PJG1173]

I remember reading about testing of different knock sensors on tgo, but I can't find it again either. I,m going to see what I can dig up at Lowes tonight. I would really like to have a functional knock sensor on this build. The motor is real picky about timing

[Six_Shooter]

Were you experiencing false knock?

I think some was false.

[PJG1173]

So not much luck finding a 45* fitting to stick in the block for the knock sensor. I may take the header off and see if I can put the knock sensor and see if it will clear with the header back on. I have to weld a crack in the collector anyway. I think I'm working backwards on this. Another question I have is since I have a NP208 tcase with no provission for a VSS I found one of these at the right price (free)
IMAG0391.jpg
Would I be able to use this? If so would I still need a VSSB/DRAC?

[belaw]

Another question I have is since I have a NP208 tcase with no provission for a VSS I found one of these at the right price (free)
IMAG0391.jpg
Would I be able to use this? If so would I still need a VSSB/DRAC?

I'm a fellow TBI noob and I've been trying to figure out "hardware" issues- including VSS for a transfer case- too.

That's an 8 pulse (8,000 pulses per mile) speedometer sender, probably for an aftermarket gauge. Unfortunately a '7427 requires a 2-pulse input for VSS. Adding a VSSB/DRAC won't help with that sender, because they're calibrated to receive a 40 pulse AC signal.

If you can find a 2-pulse DC/square wave sender you can feed the output directly to your PCM . The VSS from Jags That Run is the only plug-and-play unit I've found.

[PJG1173]

IDK what that cable is/was for. i figured its worth a shot for the price. having the VSS isn't a requirement, but it would be nice for idle.

My other alternative is to get the toyota speedo working and see what kind of signal I can pull from the cruise control. I think with some crafty grinding I can get the toy speedo cable to fit the chevy transfer case.

This is what was rigged up on my buddy's truck when he bought it. not sure who did it but it works.
Attachment 2887

[belaw]

I'm 99% sure Toyota used a 4-pulse generator; I would check on Mud or Pirate before spending a lot of time on it.

[PJG1173]

Just an update. I finished the wire harness over the weekend and installed it. I also roughed in a startup tune for it definately going to need some work. of course i forgot to run a wire for the coil which was real frustrating as I sat and stared at the schematics for an hour or so... then of course the transposed wires on the 454 tbi didn't help it run when once started. acording to UPS my WBo2 should be here today so I can really start trying to tune this thing. a few questions before I start on this.

base timing. how much is too much? when carbed this setup ran 21* initial 0* vac and 0* mech. it ran decent but would idle real rich. I figured it was because the carb was about toast, but now with efi it does the same thing. right now I have 10* base and 21* in the idle area of the spark table. no mater how much fuel I give or remove at idle it still puffs black/grey smoke and makes your eyes water. I adjusted the ve table for the best possible MAP reading, but it is still pig rich. I know with this cam I have some "self egring" or reversion going on from the amount of valve overlap. I have read on other forums that people have ran up to 30* initial timing with this cam carbed. would that still be possible EFI? I'm assuming so.

also does anyone know how to make $0D go open loop idle?

info on my build
87 Toyota 4runner
chevy 355
comp extreme energy 4x4 280hr cam
ported and polished vortec heads
air gap vortec intake
block hugger hedders
th350 trans
3000 ACC stall
5.29 gears
44x18.5x15 super swamper tsl
454 TB
454 injectors 83#
16168625 ecu running $0D

[EagleMark]

Min tempreture for closed loop should work to keep in open loop and with that cam will probably have to keep it an open loop idle, or just open loop always and tune via wideband.

30 to 35 degrees advance and more is needed for big cams and the reversion acting like an EGR, timing must drop right after that, can do with EFI and not carb distributor. Watch your Warm Spark Bias to see where timing really is compared to Main Spark Table.

Raise idle to 900 plus for a start.

Closed loop at idle with a cam like that is giving you wrong info, it's lying!

There's a Vortec head bin around here somewhere would be a good start for timing table after adding timing to idle.

It's going to idle rich and smell bad even running right, don't use your nose for AFR, it's a bad gauge.

[PJG1173]

once I get the WB installed and make sure my cobbled up knock sensor setup is going to work, I'll try to experiment with different settings. right now Idle is set for 850 as it was when carbed. I have also read on various fourms that people set idle around 900 +/- 50 for similar cams. I was kind of thinking that this would end up being a strictly open loop tune. right now it moves on its own power so its not stuck in front of my garage so I'll mess with it as time allows.

[EagleMark]

Wait, what are the cam specs @.050 ? What I saw online was not that bad... should be able to run closed loop... but it was 1000 RPM to 7000 RPM range.

[belaw]

There's a Vortec head bin around here somewhere would be a good start for timing table after adding timing to idle.

Since Mark shared this with me in another thread I thought I'd pass it on:

http://www.gearhead-efi.com/Fuel-Inj...ull=1#post2902

[PJG1173]

The cam is this http://www.compcams.com/Company/CC/c...?csid=167&sb=2 duration is 230/234

[EagleMark]

I've done that before, looked up a cam and had differant specs. Yours is more radical then the one I saw, power from 1800 RPM up = not good idle...