Proposed setup thanks

For discussing injector selection, manifold modifications, throttle bodies, fuel supply system design and construction, and FIdle valves and IACs.
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fjdog
MegaSquirt Newbie
Posts: 1
Joined: Tue Nov 02, 2004 7:13 pm
Location: Salem, OR

Proposed setup thanks

Post by fjdog »

First, I wanted to give some feedback to the megasquirt community. A thanks is in order! I have been running my 1987 Suzuki Samurai with this crazy little box for a couple years now with predictably decent results. The megasquirt has never left me stranded through many off-roading trips.

With that said, there are still some issues I have never been able to work out. Primarily, cold starts are an issue. I think it is due to my fuel pump check valve, but I am not 100% certain. Also, I have got the tuning pretty close, but under some conditions it either runs too lean or too rich at idle. I seem to not have quite enough adjustment available with the low impedance injector in the tbi. Also, the darn thing seems a little under-powered compared to the weber carb I used to have on the engine.

I have been considering redoing my fuel system to run two smaller high impedance injectors in a “throttle-body spacer” type block directly under the tbi with a high-pressure external fuel pump and an external fuel pressure regulator. The injectors would face each other at 180 degrees from one another and 90 degrees from the direction of airflow. I don’t think I have quite enough room to fit 4 injectors (and finding properly sized ones for this 1.3 l beast might be challenging). So, here’s where the questions start:

1. Do you all think this scenario would be easier to tune/ provide any better performance than the tbi setup? (more simply put: Is this a good idea or a waste of time?)

2. I am thinking about using mostly msd stuff (fuel pump, vacuum-referenced fuel pressure regulator, temp sensors) and possibly accel injectors and hoping not to have to use a surge tank, but could if need be. Will the external fuel pump do OK without the surge tank? Any suggestions on the components I am thinking about?

3. Any comments on the injector positioning? Is 90 degree orientation bad?

I know these are a bunch of questions, so thanks in advance even if you can tackle one or two.

Roland
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