Fuel Injection Newbie - Help Needed!

[cwat1982]

Hello all,

Engine info I was passed on from OE:
- 2095cc motor
- 8.5 to 1 compression ratio
- VW AS41 dual relief case (#043-101-101/2A)
- Scat 78mm chromoly balanced crank
- 8 dowel flywheel
- 5.4 H beam VW connecting rods
- Mahle 92mm forged pistons
- Engle W110 camshaft
- Heads??? (Stamped 043-101-355C)
- Dual valve springs
- Solid rocker shaft kit
- NGK copper spark plug wires
- NGK spark plugs (#D6EA)
- Trimil 1 5/8" sidewinder exhaust
- Flowmaster Super HP-2 muffler

More info on my buggy can be seen here - https://www.thesamba.com/vw/forum/viewtopic.php?t=...p;start=20

Fuel injection kit:
- Aeromotive pre pump fuel filter
- Aeromotive A1000 fuel pump
- Aeromotive post pump fuel filter
- 48mm CB Performance throttle bodies (modified to 52mm)
- Precision Turbo 50lb/hr injectors
- Magnafuel Quickstar MP-9925 fuel regulator
- Haltech sport 1000 ECU
- Haltech LS1 coils
- Cam sync, crank trigger, Innovate LC-1 O2 senor/controller

Prior to installing the EFI kit the engine ran fine with dual HMPX 44's, had the rare backfire when it was warming up and once in awhile a backfire out the carbs. As well I would have to sit in the car and give it a little gas for ~3-5 minutes while it warmed up before it maintained a good idle. That being said drivability was not effected. These are the issues that pushed me towards EFI.

Since installing the kit I can start the buggy but had major bogging issues when reaching ~2500rpm, and again around ~3500rpm. Needed help so passed it onto a shop with Dyno, these are the notes thus far:

"Started vehicle, find only running driver side bank of cylinders. Passenger side header primaries cold. Remove pass side spark plugs, find plugs appear fouled. Compression test and find 100-110psi on both cylinders. Clean plugs and reinstall. Find now running on all cylinders. replace spark plugs with new set of spark plugs in all cylinders. Run vehicle, find idles ok but backfires and sputters with load or RPM increasing. Adjust ignition timing plus or minus 10 degrees from start point, adjust fuel plus or minus 50% and find no change makes improvement to condition. Find vehicle will backfire from throttle bodies. Check primary tube temperatures and find driver bank 300'F at idle, passenger bank 450'F. Remove throttle linkage, find passenger bank throttle bodies can not fully close. Adjust driver throttle bodies to match and adjust linkage. Find all exhaust temperatures 400-450'F. Readjust timing and fuel to try to correct backfiring condition and no remedy found. Monitored timing with light and did not appear to drift."

Hoping someone might have had similar issues in the past and can point me in the right direction.

Cheers,
CWAT
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1970 Joe Poty Sand Rover T Bug Pickup, 2095cc

[Paul.H]

Ridiculously oversize throttles and injectors way too big -Good luck

[UK Luke 72]

Yeah that's gonna be a dog. You need injectors half the size, and if you get it on the road, throttle resolution will be horrendous.
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2276 Beetle build https://www.thesamba.com/vw/forum/viewtopic.php?t=670744&highlight=2276+beetle+daily
2276 EFI Conversion https://www.thesamba.com/vw/forum/viewtopic.php?t=689172

[sled]

those throttle bodies are for a HUGE engine turning HIGH rpms, like 2387+ spinning 9000 or more.

throttle bodies flow more than a carburetor of the same "bore" as their only restrictions are the throttle plate and shaft...no main or auxiliary venturi.


your engine is quite mild, being a 2095 with only a 110 cam and 8.5:1 compression. I would have had 40mm carbs with maybe 32 or 34 vents depending on the valve size, which you don't appear to know. Those could be stock valve heads with little to no port work

your initial carb issues sound like tuning issues to me, not running carbs themselves.

if you're going to stick with the EFI, you're going to need to swap out some serious parts.
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drive your split.

[cwat1982]

Thanks for the feedback.

When I purchased the kit I knew it was much more then the engine needed but was told it could be tuned back to suit the motor. If not possible could I just replace with smaller injectors or would I need to go smaller throttle bodies as well?
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1970 Joe Poty Sand Rover T Bug Pickup, 2095cc

[sled]

[UK Luke 72]

[Dale M.]

40mm TB's would be big enough...
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“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
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All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...

[clonebug]

The injectors shouldn't be a problem. Lot's of engines are EFI with bigger injectors than that.
I run 60# injectors on my 1679 so surely your 2095 can handle a 50 lb. injector.
Unless the Haltech ECU is not capable of handling it which I highly doubt.
I suggest getting the user manual out and reading it over and over and over until you are intimate with all the sensors and system.
You will need to learn it sooner or later and once you play with it a bit you will start picking things up on how stuff works.
Tuning an engine is a sort of personal thing because you tune it the way YOU prefer it to run.

Those Big TB's will make it more of a challenge to tune of course but you might be able to tune off the TPS instead of MAP.....or a combination of both.
the other option is to buy smaller TB's or trade for smaller ones.
One other option is to run a single center mounted TB which is not such a bad thing. If you want a nice driver you will be able to tune a single TB easier and get some miles on it.
You can always go for performance later when you have time but usually once it's driving good most people just want to drive it instead of working or always tuning it.
Get some stock style CB EFI intakes and build your own center section with a TB of your choice. A mid 90's Volvo 740 Turbo TB would work good and be easy to install.
Ebay has them for sale usually for a decent price. I bought one myself last year to keep as a spare for a later project.
There are others but you just have to make sure they turn the right way to be able to hook it up to the throttle cable easily.
You could also find one that has an idle valve built in if you want that option.
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[Paul.H]

I'd sell the lot to the dude on here with the 2.8 autocraft motor

[oprn]

[cwat1982]

Cost wasn't really an issue with this one (obviously ), I was struggling a little with the carbs after rejetting a couple times and even a pro tune (which ran great until I brought the buggy back home). Temperature and humidity go through some crazy swings up here and I just was done trying to deal with it. EFI seemed like a set it and forget it option.

If it costs a little more to get it done I'm still pumped about the decision and just want to get this thing back on the road because my kids love cruising around in it even more then I do.

Sounds like smaller injectors first (cheap option to try), see if that's successful and if not invest in some smaller throttle bodies. Thanks for the input.
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1970 Joe Poty Sand Rover T Bug Pickup, 2095cc

[Paul.H]

[UK Luke 72]

[Paul.H]

[cwat1982]

Was tinkering and banging my head against the wall but making baby steps in the right direction and waiting to post a more positive update then just work in progress.

Went through and confirmed wiring and double checked everything I could, got to the point of where the engine ran and was getting great throttle response but once the engine was seeing load it would seriously bog down. Was only able to get the clutch out in first gear a few times but could not build any speed.

After this I was extremely fortunate! A friend who has been helping out offered space at his garage and wanted to give it a good go over. He has a boatload of experience with engine builds and EFI setups in his cars (1200-1800 HP Mustangs and a few other toys). An hour after dropping off the buggy I get a message that the car is sounding better, the next evening I get a video of Kolby driving around the neighborhood .

Cold start took a little effort last night, but after a 5 minute warmup it was able to hold idle so more more tuning required there. First ride with the girls in a couple years and we all loved it. Car drives great, good throttle response, pulls through 120kmph no problem. Back in love again!
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1970 Joe Poty Sand Rover T Bug Pickup, 2095cc

[Nogindrops]

When I switched my car to EFI, I ran into some trouble like you. It was rough to start and kept stalling. I tried fixing things by adjusting parts and checking the spark plugs, similar to what you did. But what really fixed it for me wasn't just making those adjustments.

The big change happened when I got a new fuel pump. The EFI needs a steady flow of fuel, and my old pump wasn't cutting it, especially when I pushed the car. Swapping to a better fuel pump made a huge difference.

I found a way how to find fuel pumps at a good price and ended up paying around $150. The engine started running smoothly without the bogging and stalling issues I had before. I could really feel the difference in how the car handled, especially at higher RPMs.