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[PhilStubbs]

I have a 7747(I think) Ecu for a 1990 silverado 350 with TBI. If you pop the small cover on the top with 2 screws in it, there are two chips under it. Can I just remove the 28 pin chip, put a socket in it's place and tune away? The only reason I ask is cause I saw some sort of adaptor on the moates site that plugged into the ecu and had a socket already installed. 

[snm95ls]

You have to keep the resister pack IIRC, so you pretty much have to get the adapter from Moates.

[PhilStubbs]

It that what's under the chip? The chip seems to sit high. I haven't opened it up other than just removing the small cover

[snm95ls]

It that what's under the chip? The chip seems to sit high. I haven't opened it up other than just removing the small cover

The whole deal is referred to as a memcal; there is the ROM and the resister pack that act as limp mode tables.  You might be able to rig something up, but the adapter is too cheap to pass up on.



I guess i you wanted to you could try to remove the ROM, and replace it with an SF512 with he proper addressing, but I honestly never got a chance to dig that far when I was messing with this stuff.

[PhilStubbs]

It's not the price of the adaptor, it's more about time. I really need this truck right now to move some stuff and it runs shitty once it warms up. I put a 270hp 350 crate engine in it and the stock tune is far from ideal. It does run real nice cold, I wonder if I could stick a resistor in place of the coolant sensor temporarily.

[snm95ls]

That may be your easiest temporary solution.

If you happened to have an adjustable PR, you could fudge the fuel pressure to compensate as well, but chances are that you don't.

[PhilStubbs]

no, i dont have one. i thought about that.

the resistor would only be temporary for sure. i plan to actually tune it to run right. i also have boost in mind in a year or so. i have a feeling it wont be TBI though, or if it is, it will be multiple units run with an injector driver

i opened up a spare 7747 ecu that i have and its a 24 pin chip and not a 28 pin. i will need an adapter for sure

[snm95ls]

no, i dont have one. i thought about that.

the resistor would only be temporary for sure. i plan to actually tune it to run right. i also have boost in mind in a year or so. i have a feeling it wont be TBI though, or if it is, it will be multiple units run with an injector driver

i opened up a spare 7747 ecu that i have and its a 24 pin chip and not a 28 pin. i will need an adapter for sure

he injection scheme along with a relatively archaic and limited selection of injectors really limits the amount of power you can make with a TBI system.

The FPR isn't even referenced to manifold pressure either IIRC, so you would have to battle that issue as well.

[PhilStubbs]

I know there is better stuff out there but since the day I brought this truck home I have had this idea to get a nice low rpm 4bbl carb manifold, build a sheet metal elbow and mount an ls1 tb on it. Then make a fuel rail to hold 2 1kcc injectors and mount them in the sheet metal elbow with a Honda fpr and a walbro 255 in the tank. Hopefully I could run it all with the stock ecu tuned for the setup.

If there is some reason that idea won't work, I will probably just use lt1 parts and go mpfi

[PhilStubbs]

Quick update, I found some random resistor from an ecu vtec kit and stuck it in there. My scanner read 32*f for coolant temp so I thought win. Truck won't start with the resistor, but fires right up with the sensor plugged in.

I just placed a moates order for the adaptor. I will just tune it

[snm95ls]

32 degrees F is pretty damn cold.  Your cranking fuel is substantially higher at that temperature compared to ambient.

Dunno if you have done it already, but start searching for the definition files and BIN files to get started when your adapter shows up.

Also might want to find out what injectors you have and see if they will even support the power you currently have at stock fuel pressure.  IIRC, the calculations are a bit different, but it has been many years since I have dealt with TBI stuff in any deep manner.

If you were to stick with TBI, I would suggest the EBL from Dynamic EFI as it is specifically geared towards TBI, and has some code updates to make it work much better, but if you are gonna turn the wick up even more in the future, I wouldn't stick with TBI; at least not a 2BBL unit.

EDIT:  Here is a good breakdown on the issues regarding TBI fueling and injector sizing.

http://www.dynamicefi.com/TBI_Fueling.php

[PhilStubbs]

I have a feeling I will be putting the 65lbhr "cop car" injectors in to run it right. The 55lbhr injectors might do it, but I'm sure it will be well above 80% duty cycle.

My power goals are in tq and not hp. I want 400ftlb at 3500rpm or so and I'm guessing 350-375hp. I see some sort of multi port setup in my future, but I just need the truck to run right for now.

I will probably download tuner pro and research a bunch this weekend. I know the adaptor won't show up before Monday.

[PhilStubbs]

so, an update. got this bitch running pretty decently on a chip, but old school v8's want some odd shit to run right. lol

fuel really tapers off after 2700rpm or so. i still need an aldl cable to really get this done, but i am making progress.

one issue that is really slowing me down is that the truck wont run on the ostrich. i got the socket booster from moates and no matter what i do it wont run on the ostrich. i got about 5 min once to play with idle using the ostrich, but other than that, i have had to just burn a chip for any changes. gets pretty tedious that way. anyone know what i can do? its a 7747 ecm by the way

[snm95ls]

Remember, that engine probably has peak torque right around 2700 RPM, so it makes sense.  Compare that to the Average Honduh where peak torque is much higher, but throughout the usable powerband it does not vary nearly as much.

Do you have to change the internal jumper settings in the ostrich to use with the adapter maybe?

Ostrich 1 or 2?

[PhilStubbs]

its the ostrich 2. it worked for about 5 min while i got the idle set, then i started playing with some throttle tip in adjustments, got a lean pop and that was the end of the ostrich working. i cant imagine they are related, but it happened at the same time. i didnt know there was anything to adjust inside an ostrich. i havent seen anything in my google searching

[snm95ls]

its the ostrich 2. it worked for about 5 min while i got the idle set, then i started playing with some throttle tip in adjustments, got a lean pop and that was the end of the ostrich working. i cant imagine they are related, but it happened at the same time. i didnt know there was anything to adjust inside an ostrich. i havent seen anything in my google searching

http://www.moates.net/documentation.php?documentation_id=24

[PhilStubbs]

The ostrich 2 has switches on the outside in place of those jumpers.

[snm95ls]

The ostrich 2 has switches on the outside in place of those jumpers.

Ah, didn't know that.  I have the OG Ostrich.

 

[PhilStubbs]

i tried it again and got a little longer out of it this time. i hooked it all up and uploaded the bin with the key on.

it still only lasted for a few min though.