Printable View
Okay, I think we are going to go SD, and just hide it. The 7730 ECM looks good, we can do that. I assume that AUJP is the code to use, but can't find anything about manual trannys and AUJP, is it not a good idea to use AUJP with a manual? I just scanned the AUJP disassembly, but can't find any settings for manual trans. (only a quick scan however) I got offered an 8051 out of a 95 firechicken, but will pass as I don't want to deal with optispark and all the other stuff it does.
22RE = 91.9mm bore.
quad4 = 92mm bore.
i'd say that's a pretty nice match for the knock filter.
I would say so. So stroke doesn't matter, just bore diameter? Also, do you have to modify the memcal for the frequency of the knock sensor you use?
as long as you use an appropriate 3900 ohm sensor, you should be fine.
Okay guys, BIG question...... I was thinking about all the reading I have done in the past, and seemed to remember a $0D maf setup. So I looked on this website at Marks $0d thread and found $0d MAF and MPFI . It would make sense to me to use that as I have 100's of hours staring at $0d code. Am I missing something here? We can use a GM MAF, as we are modifying the AIR intake anyways. I doubt most smog techs would know the difference anyways, MAF sensor.....check.
And there's your sign! :happy:
But back to what memcal for 4 cylinder that will be compatable with those mods? All that stuff was done for V8 and memcal that came with them.
Just to clarify I saved and organized other peoples work in that thread and had no part of the cool development.
grab a Q4 MEMCAL and try it?
are there actual mods to the MEMCAL? i only briefly looked at the subject and it looked like there were internal mods to the PCM, but that was about it.
I remember an internal mod to the drivers for the injectors, and a jumper on the memcal for MPFI, is that what you are talking about? I actually did that for a friend for a 383 TPI project he did, but it was MAP. IIRC the memcal selects the number of cylinders correct? There is a parameter in $0d at L4142 for number of cylinders, but not sure if that is all that needs changing.
<< edit>> I looked at the code a little more, and it appears that 8 cyl is hard coded in several places and may need some modification to make it work. I haven't looked at a 6 cyl hac, but I guess I should to make sure.
There are three reasons to select the correct memcal. First is to ensure you have the correct fuel delivery mode enabled. Second is ensuring you can match the knock filter circuitry with the sensor and engine. Third is to have redundant fuel / limp home mode matching the engine configuration so the vehicle can be driven if the primary control logic fails. If we postulate that 99% of mildly to wildly modified systems have done nothing to match RFD to configuration, then the job gets easier. The knock sensor circuitry is a soldered in board which can be removed with less effort than installing a ZIF socket for the main eprom. Fuel mode select is a simple resistor network which has been decoded and measured across several memcals providing a consistent pattern. http://www.gearhead-efi.com/Fuel-Inj...ull=1#post3374 Interesting to note is that one of the Quad 4 memcals used "single point TBI" as the fuel delivery mode rather than "four cylinder pfi" mode. Armed with this information, memcals become nothing more than physical devices to store and connect various hardware to the ecm, and a source for parts for future modification.
Knock frequency has a very direct relationship to the speed of sound. Sound travels slower in warm, less dense air and takes longer to reach cylinder walls with a larger bore diameter. Discounting cylinder temperature you can use the following formula to calculate a theoretical frequency for knock based on bore size: 900/(3.14*cylinder radius)
Or head to this handy online calculator: http://www.phormula.co.uk/KnockCalculator.aspx
Mark just posted some info confirming that GM knock sensors are primarily tuned to 5kHz, 6kHz, or 7kHz. http://www.gearhead-efi.com/Fuel-Inj...ll=1#post18135 As we learn more about knock and sound filtering I'm sure we'll be able to make better choices using the additional information in that chart but for now the 2.3 sensor and filter seem to work well enough with my engine that I'd recommend them.
Toyota uses low impedance injectors and attaches resistors in series (the aluminum box on the RH inner fender) so high impedance drivers can be used. I chose to remove the resistors and use the peak and hold driver ability of my 7749. If you use the 7730 you will likely want to leave the resistors in and keep the ecm operating in saturated mode (no injector sense jumper attached). Additionally, because the 7730 only uses one injector driver you should choose "single point tbi" or "eight cylinder pfi" mode as opposed to "four cylinder pfi" which alternates injector firing between two drivers. Choosing the 7427 means you can leave the fuel select mode on the V8 memcal intact (the same voltage is used for 4 cyl PFI or alternating bank TBI) and use peak and hold mode to drive the injectors. You shouldn't need to change sense resistors in the pcm or upgrade the drivers because the total current draw through (4) Toy injectors is similar to (2) tbi injectors.
I cannot add much about $0D with MAF operating a four cylinder engine. The calibrations I've studied which have a knumcyl variable for the number of cylinders will do a conversion to the time variable representing engine speed. After conversion it's equal to an eight cylinder value so this may be an option if not already included. I might have time to dig out my notes later today or tonight.
Found this in a 22RE with a home made turbo!
GM 7730 style ECU from a 92 Lumina Z34
Memcal (chip inside ECU) from a 91 Cutlass Quad 4
http://www.22rte-trucks.com/simplema...php?topic=1636
a 92 Z34 would be a 16149396.... good choice IMO!
a 1227727 would work underhood then, 1227730 if in-cabin.
I put my 7749 in the truck where the OE ecu was but it's still not attached to anything. I'm going to have to build a bracket and shields to protect it from passenger's feet. The underhood version would be nicer but I'll bet the inspektors in the Republik of Kalifornia would catch that modification pretty quickly.
That's Lucky's Land Rover.Quote:
Originally Posted by EagleMark
That was a really neat project, I remember running across it in some other forum. I wonder if the 4.3 MAF from a 96 blazer will work for this project. I know that I may need to adjust the airflow table for it, but that can't be that bad, can it? Since we are completely redoing the air intake when we move it and switch to a cone type filter, it ought to look fairly stock. I need to find 1project2many's truck link so that I can look at his other mods. The IAC and coolant bypass especially. We are hoping to start collecting parts this month, I may start playing with code as soon as this weekend. I am excited, it would be cool to stealth convert this truck. California smog laws are very restrictive, but if it looks correct and passes the smiffer then we are good to go. We live in one of the least restrictive smog areas of California.
Post 2 of this thread...