For one thing the Carb as sold from LCE just comes as it would from the Weber OEM factory. This carb is run on probably 100 different vehicles. All requiring various tweaks to help the carb perform properly.
Some of the Mod's I've done on the 22R are:
- LCE Pro Longtube Header
- Mallory 70 Series Fuel Pump
- Weber Redline Low-Pressure Fuel regulator (not entirely needed since the Mallory is adjustable from 3-12psi (this is just 'insurance' to make sure it's regulated). The Weber 38 is a bit picky and requires 3psi Max.
- Crane Cams HI6 Fireball ignition Kit with LX92 Coil.
Changing the air flow with a larger carb, a more open exhaust system, and an ignition kit that's like 12x better than the original OEM Toyota (or greater!) all effect the setting up of the Weber 38 and really means it will need to be tuned 'mo-bettah' than it comes out of the box.
When I bought this Weber 38, I also bought the performance Weber 38 Jet kit 701-DGS for the 38-DGES carb. (Thank Gawd I did).
Here is what I've done so far (today):
First here's what the results of initial changes and testing LOOK like!
- Removed the Vacuum Assist Brake hose from the Intake manifold and attached a $25 vacuum gauge from O'reilly's. (This is 'old-school' method 'tune for max vacuum) when setting the Fuel Mixture screws.
- Start, and allow the engine to warm up. We should be OFF CHOKE Now...Top Flaps wide open.
- Adjust the IDLE SCREW to 1/2 turn IN. NO MORE, NO LESS.
- Adjusted the Fuel Mixture screws OUT until the idle SOUNDED good and engine seemed relatively stable and calm. (ie. not shaking around, or 'tractoring')
- Adjusted Fuel Mixture screws for Max Vacuum. Which is actually different from Weber's documentation.
- When I started this (#5) the vacuum was at 18".
- I adjusted for Max vacuum and vacuum when to 20.5" (GOOD'er'er :-)
- Now the good and bad News.
- BAD NEWS: I'm now 3.5 turns OUT on Fuel Mixture. Weber docs say 1.5 turns out MAX!
- GOOD NEWS: this was then corrected by changing out the two Idle Jets that were 45's to 50's from my Jet Kit.
- End results after this is that the Idle screw is at 1/2 turn IN. And the Fuel Mixture screws are 1.5 turns OUT. This gets me to the outer limit of OK and per Weber requires another Idle Jet size larger. So tomorrow I'll install the 55's from the Idle Jet Kit. With the intent/hope of getting between 1/2 turn out on the Idle Screw and 1.5 turns out on the Fuel Mixture (and my old school check/setup for Max Vacuum as well.).
I test drove the truck after this latest round and found things to be A LOT BETTER! (easy to notice).
- 22R Engine idles as low as 650 RPM stable! I set it to 750 RPM with the Idle Screw at 1/2 IN (750 rpm is per the OEM spec for Manual transmission, although I like 800 rpm better personally, Lights, Heater Fan on loads it just a bit but is still VERY stable)
- Acceleration from a stop, has no hesitation anymore (there was a slight one prior to this latest round of tuning, nothing major if you expected it).
In the morning on 11/9 I'll up from the 50's to the 55's and readjust everything and see how that behaves. While this set of changes has drastically improve cold start, idle and warm idle conditions, I can tell it still could be a bit better so that's what I'll work on tomorrow.
Once these things are done I am pretty sure I need to change more of the Jets. Stop to Low speed, and low-mid range RPM's pull very nice now (although I think that can improve also). I think the Higher RPM's should pull harder than they do. It 'feels' like there's more there, but something's restricting it. I suspect the other jets will need to be swapped out as well.
But this has put a really warm fuzzy feeling in my heart. After spending all this money, and time installing things, and to start to see some more reliable results is really encouraging.
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