The 8062 doesn't seem to have as many parameters to adjust as the 7747.
For my case, a 3.4 sfi pulled and topped with a TBI.
I would have thought that 8062 with the 2.8 bin would have been easier to adapt to the 3.4, but that seems to be more difficult than running the 1227747, but then there is the spark latency that I have talked with you about.
Honestly, I think I could be making this more difficult than necessary.
Originally Posted by damanx
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
there are people who swap just the 2.8 top end onto the 3.4 block and i think maybe an injector or fuel pressure change and don't have many/any issues.
i'm quite confused as to how that can happen and you run into so much trouble?
unless they have different definitions of "it runs correctly".
1995 Chevrolet Monte Carlo LS 3100 + 4T60E
.................................................. .......^^^^^^^^^^....................
It could very well be both.
I don't know why I am having so much difficulty other than maybe I am expecting too much.
Right now, I can't remember the reasons for going from the 8062 to the 7747 other than that there is A LOT more support so to speak for the 7747 than the 8062.
Maybe the easiest thing for me to do is to start over from scratch and go from there, I have no idea to be honest.
He's convinced that everyone else's 3.4 are knocking and running lean,CONVINCED, and spouting off about it, when he can't even get his to run well.
http://www.s10forum.com/forum/f106/w...-setup-575985/
If that sounded harsh, it was supposed to, at least a little. I've always gone by the old idea of be master of your own domain before telling others how to run theirs...
That out of the way, there are a few things to look at to select a bin to use.
First is what ECM is being used, this will determine what code(s) can be used and can make the choice significantly easier. The flip side to this is that sometimes you need to look at the application first and then choose the ECM based on that.
For example:
Someone using a 6 cylinder engine that is naturally aspirated, and a manual, well choices for ECM are pretty open here and many people will be able to start with their original ECM or a similar ECM. However, if that same 6 cylinder was now equipped with a turbocharger, this cuts down on the available code that is capable of dealing with positive intake pressure. In this case you look at the code capable of dealing with this, which will determine what ECM is used. Just to take this example a little farther, $8F and $58 will both run a combination like this, but wait there's a couple gotchas here. $8F was used on a V6 with DIS, where as $58 was used on a 4.3 with a dizzy. So now the tuner would have to look at the ignition system being used to match up, and/or decide if they can deal with the code changes to make one run on the other, if that's what is decided. Let's say $58 was decided upon, because it has much better support than $8F (time researching pays dividends here). What ECM(s) will this code run in? Well it was originally used in the 1227749. Hmm, these are a little hard to find, but through some research it is shown that the '1227727 and the 1227730 are in the same ECM family and will also run the same code and are much easier to find. The rest gets pretty easy after that.
In the case of a TBI engine, the choice is similar but a little different. If there is an electronic automatic trans then a newer PCM will be needed that can run the trans will pretty much dictate the ECM to use, or at least the variants. If there is a non electronic trans or manual trans, then the choice is a little more open. The newer PCMs can still be used, but does take more effort to disable the E-trans controls and diagnostic codes, but well worth it.
Looking a little narrower at the 1227747 ECM, as your particular case is, I would look at the engine cylinder count, trans type (manual or auto, and if it's auto that the trans matches, since there are some '7747 bins that were for TH400 transmissions), and then other options, like air conditioning, evap canister, etc, etc. I would also choose the latest bin for that application, since any drive-ability issues of earlier calibrations will usually be sorted out in the last known release.
As far as the latency settings go, I'm only aware of 2 or 3 different latency tables for the TBI/TPI modules. A search over at TGO in the DIY PROM forum will return those tables. I have found though that even using the wrong latency table will not be the end of the world, just that commanded timing may not be actual crank timing.
Remember: Give the engine what it wants, not what you think it needs.
The man who says something is impossible, is usually interrupted by the man doing it.
You are absolutely correct and it's only harsh if I am unjustly offended by it, BUT I am not because you are correct that I don't have room to speak since I can't get my engine tuning in order.
But on the flip side, as I have stated on that board, I acknowledged that there are many others that are members there that know WAY more about this and yet, they choose to not correct me or even offer advice/criticism to anything I have written.
I'd also like to point out that I have on more than one occasion posted that anyone doing this conversion, or has done this conversion, should come to this site because you guys know this stuff better than I.
On the note about the assuming their engines are running lean, I do know for fact that JimmyKicker has yet to put a cable to a computer to see how his engine is running.
He's taken and done pretty much the same conversion that I have done and is still using a 1228062 with an unmodified bin. As with most other people, is also using the larger 4.3 throttle body.
Am I incorrect to assume that since no modifications were made to the bin to accommodate the different injectors and the probability that the fuel pressure hasn't been accounted for that they are most likely running leaner than they should be?
I'm just trying to help where I can and offer my apologies if anything I have written over there is incorrect.
On that note, I'd be willing to throw a stock 8062 and a stock 2.8 bin on the truck, turn the fuel pressure down to 9-10 psi and run it for a few datalogs if you'd like. While that my not provide data applicable to all, it would certainly provide good data as a baseline.
That is great info and I appreciate it.
I guess I probably should not be trying to compare to the SFI bin because that I think is probably clouding the problems even more.
Repeat this until it's second nature, and is the first thing that comes to mind when you want to tell other people how their engines are running:
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
No two engines are alike, even with the same sum of parts.
Just because YOUR engine may run one way, with the exact same parts as the next guy does not automatically mean that they are both running with the same numbers. Numbers meaning, what the ECM is seeing and doing.
There are some mechanical tricks that people can do, and have done that will allow an engine to run well, maybe not perfect, maybe not up to its potential, but well enough to be able to be reliable and do the task it was assigned to do for that particular driver.
The reason no one has said anything on that site is that many times you have come across as combatant, and argumentative when someone has told you you are wrong, so for many it's just not worth getting into the argument over.
What are you comparing to in the SFI bins?
SFI and TBI fueling are very different, and are very difficult to compare in the raw numbers, without having a LOT of experience doing so, even comparing TBI to MPFI, or MPFI to SFI can be confusing, due to the different formulas involved, and what fueling algorithm GM decided to use that day they wrote the code. There are different fuel delivery models that were used in the MPFI bins in the OBD1 ECMs. I don't have enough experience with the OBDII (SFI) PCMs to know whether they decided to stick to one algorithm or not.
My advice at this point, if you're having a tough time tuning it well, starting with a fresh unmodified bin might be the best bet. I do this every now and then, sometimes just to see how quickly I can re-tune it, but also as a sanity check sometimes, so that I know that everything I changed in the last set of bins was correct to get me to where I was.
You can choose to do this with the '8062 or the '7747 or better yet, both, and see what the overall differences are. If you're really keen, I'd suggest going to a '7427, to get the 8192 baud datalogging and a bunch of other parts of the updated code. As I mentioned previously you will need to disable the e-trans stuff to do so in your application, but many people that have made the switch have been happy with the results.
The best way IMO to switch over to an unknown ECM is to make an adapter harness that will allow you to plug in the new ECM in place of the known and switch back quickly if need be, this is especially good to do if the vehicle in question is a daily driver or primary form of transportation, since it can take several hours sometimes to re-pin one way and then go back to the original ECM. I have done this on several occasions, including a '7747 to '7730 adapter, '7148 to '7749, and '7749 to '765.
I usually use a junk ECM to grab the donor connectors from and then use the plugs for the donor harness as cut out of a vehicle to complete the harness. I use crimp tyle DB computer pins to make the wire to donor connector connections, since soldering the wire directly to the pins didn't seem to hold up as well.
A picture of the '7148 to '7749 harness, the extra green wire is for the MAP input, since the '7148 was a MAF ECM.
More pictures here: http://www.gearhead-efi.com/Fuel-Inj...ne-or-started&
Hopefully that gives you some ideas.
The man who says something is impossible, is usually interrupted by the man doing it.
Can you point out those threads where I've been told that I was wrong, and HONESTLY, I will post an apology in each one. I am being sincere.
I'm not trying to be an ass here so please don't take it as if I am because I admit I am frustrated. I am obviously making this more difficult than need be but on the other hand, I try to figure things out on my own before I try to essentially bombard any site with repetitive questions and then turn into a PITA.
About the only thing from the SFI bin that I was really looking into was the timing table. The BIN doesn't clarify an "initial timing" mark so to speak so the timing table confused me.
I will look into the 7427 and will try that if you think that is worth a shot.
I'd really like to try to get a better understanding and if you are willing to help me with this, I'll do my damndest to not be an ass and will do whatever I can to constructively give back to the community, even as far as building aldl cables out of my pocket.
LOLOL
Sadly, I agree.........
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