madkaw

Well like I said, for the majority of first generation FI Z owners, 75-83 models, there is limited engine modifications that can be done because of the ECU limitations. It's a shame that the guys wanting more HP have to revert back to carbs. I kind of understand this because of the black magic of smoke and wires. Plus there's much more support for carbs than aftermarket EMS on these forums. It seems that there is strong support for the MS systems on Hybridz and on the MSEFI forums. I'd like to see more done on this site . I know this a site more geared for the purist, but updated the computer that runs your car will hardly be noticed for most.

You need to be more scientific about this. First, please use punctuation - your posts are difficult to read. Don't worry about the filter air bubble . They rarely fill all the way up. You need to make sure the electric pump is working and putting out the volume of fuel it's supposed to. Running a turbo charged motor lean will destroy the motor. You could disconnect the fuel line at the carb and run the pump to see what comes out and how much. You need a gauge as suggested. You might need to take the carb apart and check for cleanliness.

Carbon fouled plugs can be cleaned an reused. I just went thru this with my carbs. Maybe after you foul the plugs a bunch of times and finally figure out your issue you can replace, but not necessary after fuel fouling. You talked earlier about rejetting the carbs- why? What's your fuel pressure and why did you replace the pump?

A person could look at Megasquirt the same as this Patton set-up- but with much more flexibility.

I feel like I've been "called out" seeing my user name starting a thread which I haven't been on- I have considered this, but I am educating myself as we speak. I know there will be only a few on this site that would see the thread as useful, but it is grassroots motoring really. Let's face it, we have Z therapy carbs, and Triple carbs to modify old school carb induction, but not much for the other fuel injected crowd. I personally think triples are cool, but now I think a modified fuel injection would be cooler:cool: I am getting a bit tired of the float bowl smell of the triples, and the lack of precise tuning ability. The fuel injection idea was intimidating to me early, but after doing some reading I realize how simple it is with less parts to give troubles. In fact, my triples will be going on the market this fall to help pay for my progression to FI. I have recently purchased the Megasquirt MS3x ECU with harnesses. The long term plan is to wire up the ECU and first use it to run spark on my engine. I elected this route so I can keep my existing ignition on the car and usable as I develop my distributorless ignition. There are several members that have done this already with good results(Leon). One big benefit with this is designing your on timing curve. I think Leon gained a decent % with his set-up. The members that are already have FI cars are far ahead of me since you already have an intake that supports FI now. With something like MS you can modify your engine and have a computer to keep up and take advantage of this. You could also throw away those expensive parts like your MAF and run a simpler MAP system. Performance FI is where its at and where I want to go.

Vacuum Advance- how is it supposed to work? - ChevyTalk --The Social Network for Chevy Fans

Hope Guy doesn't mind this thread diversion. VA is to help with emissions and MPG . It should only be involved during low load high vacuum situations. That's why I asked if this is a racing motor. Running a street dizzy on a race motor is a compromise anyhow, but having the VA working will probably limit total timing under full load( using OEM figures)- which you don't want .

Jeff, Not sure if I've ever seen timing checked WITH VA attached. The 55 you are seeing is probably with 17 degrees vacuum advance. I think that dizzy adds 17 degrees mechanical. Is this a race motor? If so , I would forget that VA and run around 17 initial. How much mechanical advance does the spreadsheet show?

Timing is probably critical with that turbo charged engine. OEM timing might not be relevant and the OP might find that initial timing is way advanced and mechanical timing has been deactivated . Pressurizing this motor changes many parameters of tune on this motor. The BIGGEST change will involve timing. Stock timing could be the demise of this motor. I would be not be surprised to see timing at 18-20 degrees PERIOD

So all the plugs looked the same? If they did, then it's something that effects all of them at the same time like ignition being weak, too much fuel pressure , etc.

I guess I don't need to mention that engine temp is critical with engine tuning. You might get that resolved before continuing the tune Good luck

And as far as the "flat top" carb, it might be the best SU for this application . The flat tops have a separate idle circuit which would be ideal for this turbo set up- which might also be the reason it doesn't idle now. With a separate idle circuit, you can have the main circuit run rich for pressurization .

How about some closer pics of the carb and the hoses going into it. Are you sure you got the hoses in the correct places? I'm curious about the hose coming off the top of the carb to the valve cover. Seems like full vacuum from the intake on the valve cover?

Remember , using a stock dizzy like I am limits me. To reach my total advance numbers I am forced to increase my initial advance, but I have no issues what so ever running 18 + degrees initial. You have much more flexibility and with proper tuning should be able to extract more HP from your motor just with timing. That's why I am installing MS and doing away with my dizzy all together

I don't think you will find much info on hear concerning graphed timing curves. As posted above, using someone else's curve might not work for your engine anyway. There are very few L26 s with a MN47 head around here -let alone with your cam. My only suggestion would be to make a good hearing device to pick up the sound of detonation. You can search for what others have done on the internet as far as putting a mic somewhere on the engine and wearing a headset of some kind to listen for pinging! They say the human ear is the best anti-knock sensor. You can try all types of springs, but unless you have an accurate butt-dyno, it will be hard to tell your results. You could try the knock limiting approach and max out timing to just before pinging, but is that where best MBT is? Only a dyno would tell. I would think the MN47 would be a very efficient head and you might not need to much timing to reach MBT. I have a small chamber head with my early e-88, and I run a lot of initial-18 degrees with no VA. I max out with 35(17 degrees mechanical) When I dynoed my car I started out with 37-38 total timing. I backed of the timing to 35 and saw no difference in MBT. I would think with triples you would want more initial then 10-IMHO

I am doing a Megasquirt conversion now. You need to get on the Megasquirt site and read, read, study and read some more. This is not the best site for your goals. You would be better off on Hybridz where this work has been done by many. There are many members who have posted their projects in great detail and will be helpful to you. The megamanual is probably one of the best resources also

You wouldn't be the first to leave the ratchet on that bolt!! Congrats on getting to drive all that hard work- it's a great feeling isn't it?

Can you elaborate more about what's blocked off and do you have anymore pictures showing the induction system ?

Timing light?

The other thing that would have jumped out at me was the rain storm. I would have suspected moisture under the dizzy cap would have caused the misfires .

When I said dirty tank, I picture you stirring up crap during fill up and this crap initially getting sucked into the sending unit. After sitting for a period of time the crap falls out and things are good again. Have you peeked inside your tank.

Haven't watched the video but the first thing that pops in my mind is dirty fuel tank

Hmmm, that is weird

Not a lot of help to find here on the L28 turbos. Someone just put a lot of work into an engine timeline which was nice since it laid out the different year heads and blocks. The easiest way is to find a complete 28ET motor because you will have all the parts( exhaust , oil pan, plumbing ), or just find the best deals on stuff and throw any motor together and pressurize it, just keep the CR down a bit. As far as LSD, do the STI swap and don't look back. OEM Subaru quality with choice of ratios and made in this century and plenty good for most moderate HP goals .

Chris, You kind of threw us a curve ball. You never mentioned that you removed the oil pump during engine swaps- which I wouldn't have assumed since its not necessary. Since you said the motor ran great before hand we were all thinking of things you might have touched, but I didn't figure on the oil pump. Anyway, it made for interesting reading