Ok, I just converted the 89Vette to a 92 F body ECM (730 ECM) which is map not maf. i had no problems... it was a pretty much painless conversion being that i used a adapter so i would not have to hack the stock harness up:) Ok, heres what i got when i started her up.... perfection. BUT, the scan tool i have been using will not "connect" or "link" now. if i do the typical A to B terminal.... i can pull codes NO problem.. pulls a code 12, and the fan comes on... perfect... (pulled a code 43 b/c i have not changed the Knock sensor yet..no biggie). But why won't the Scanner hook up?? I entered 89 corvette... 92 Camaro.... 91 camaro... 92 TA...still no link....???why??? The PROM was altered a bit from stock for the VSS, injector sizing...etc. help..please.. :banghead:

 

I've got the car running GREAT! i put in the right knock sensor, adjusted the Idle/tps by GM specs... reset the ECM... smoothe as butta..lol. car starts great, runs great.... NO CHECK ENGINE LIGHT!! yea... the speedo works, the TCC Lock up function is great... everything is fantastic. :hurray: I need to try to hook the scanner back up now... but i wouldn't see why it would hook up now and not before..... so any ideas on why the Scanner won't link with the ECM, but i can pull codes with a paperclip???

 

The scanner (or at least Diacom) requires a different ALDL pin for the 730s. The 730 has 2 pins labeled for ALDL communications. One is in the position yours is already in. The other is the position you need to move the one you already have in, to.

EDIT-Move pin E on the ALDL to pin M and you will be able to scan :thumbs:


[Modified by HighHopes85, 1:47 AM 5/27/2003]

 

thank you. gonna try it right now. so E to M.

 

BADA BING! It worked! i enter 92 F body works. :hurray: thank you so much for that edit info. I notice a few differnces in the data set up. I think it's more advanced and much more useful! it has timing advance, and retard... i mean.... jeez. the MAF 165 ecm didn't display that. i love this new set up on the 730 ECM. As soon as i'm set up to burn PROM's.... it's all over.... lol. i'll have that thing dialed into a science. I'm loving this MAP system. I can't wait to get my LT1 intake manifold in next week to!

 

one more question.... I just remembered. BLM. I know it's fuel trim... but 128 is perfect... mine is at 126. Is lower or higher richer/leaner?

 

Glad it worked out for you. Believe me, when I switched from an 85's serial data to the 730's, I had about 400% more data frames/sec being captured...PLUS Diacom will scan in NORMAL mode on the 730--this mode makes the ECM do nothing abnormal, like advance the timing, which can happen with earlier ECMs.

BLMs of 126 mean that your ECM is actually trying to take out fuel, because it is seeing a rich condition. But it is pretty close, especially after starting with a CHIP that probably was just guessed at. If you are universally under 128, then you could either mess with the injector constant in the chip or tweak the fuel pressure down just a tad--but 126 is pretty darn good IMHO after the swap.

Also, I scan as an F-body. Someone on here sent me some of their Diacom files for the 90-91 Vettes and it looks almost the same, but they have an oil temp reading that gets recorded...maybe a few other stray things. I didn't make provisions for oil temp being recorded--about the only thing I could see it being useful for is to see if oil temps have any effect on MAT reading due to oil splashing on the bottom plenum during long idle periods.

BTW, if you search the archives, enter the phrase "730 Club" in 'Topics". Now that the hard part is over, it might not help out, but there was some good info in it.

Cheers, -Matt

 

yea man. i had no idea that the next day i'd be out racing it! Runs good. I scan under a 92 Z28 5.7L. Much MUch more info on the 730! I love the fact it gives you.... Degree retard/ and actual advance reading!!! I love it! my MAT/IAT sensor is updated to that of an LS1 and put in the air box. It's just some wire and new sensor.. easy. yea, the max timing this chip has is +24*... that's crap. My lawnmower probly has more timing advance! lol. I also drilled some holes in the front liscence plate for my custom ram air intake.... and my Air temps went from stock.... 95F crusing at 75MPH to 76F at 75MPH in the same weather and all. and i haven't even put the actual intake in yet! that's just from the holes i made!! my friends call it the WS6 from the 80's :hat but i did a nice job with it. Now all i need to do is remove the dumby maf and stock airbox and replace it with a 3" mandrel bends and a C5 air bridge... and the filter behind the front plate! Now i'm on to starting my LT1 swap maybe next week....hopefully.

 

I was thinking about doing the sensor relocation, but to be honest, I do so much in-town driving that heat soak actually could be a problem. I have a couple good ideas on plotting out my MAT vs AFR/CTS/etc, but just haven't had a chance to add them to my proggie that I use for looking at my scans. If I have time, I'll be messing around with the MAP relocation like you mentioned jsut to see what it gives me--if anything at all--or if I can use the stock tables and tweak it like I need to. I have a data aquisition board that accepts some thermocouple inputs, so a few placed strategically inside the air intake and actual upper plenum, runners, and lower could show me what, if any, heat is being transfered to the air charge. It's just this time thing that I can't seem to get enough of these days!

Another thing, when you switch over tothe LT1 manifold, make sure to keep the MAP sensor mounted in a way that the line running to it does not become a drain trap. Another good idea that was pointed out on here by a fellow forum member (mebbe the LT1s mount directly on the manifold--if so, it probably isn't an issue). I just had a MAP code that kept coming back...could have been a bad ground, or could have been the line actually acting like a trap (think a trap in the bathroom sink).

The best advice I can give you now that you have some kick-**** scan data is to organize it. My method is generally to name the files something like 05260301...with the date as the first 6 digits and then I can make up to 99 runs for that day. When you/if you save the GDF file to a DBF file, then change the name of the worksheet to the driving conditions, like WOT, medium throttle, normal cruise, etc. Makes it much easier to keep track of things when doing chip changes, etc.

Good luck

 

Ok...so i have a 1991 vette and do you think running the 730 ECM would work for my application??? i know Tjwong was telling me about something like that but if you guys think it will work for me please let me know!

WHAT I HAVE
i have a 1991
383
10:5
D-1 ATI Blower
and Stock TPI

 

well, it depends on your MAF. I never looked at a 91 that close.. Look at your MAF. If yours is the little small crappy one like the 85-89 style... 730 that bad boy. if you have the NEW style of MAF from GM.... the larger, 3" looking one... your fine. Leave the MAF. Go from there. b/c the TPI MAF (at least on 85-89's) only flow like 635 ish fully modified. I'm looking for a 750CFM set up. SO, 730 ECM took care of that.:) Fare warning.... you won't be faster off the bat, you'll need to do some tuning... i mean tuning. Custom burned PROMS. I am starting to do them. I have Winbin, and TUnerCat. ordering my pocket programmer and UV eraser tomorrow... so when i get my set up dialed in perfectly.... i mean perfect. (i'm a perfectionist with this kind of stuff) i'll post or email you my PROM set up, or i can burn one for you.
Jason 89 Coupe
LT1 manifold, 730ECM, all the bolt ons, Hedman headers, 2.5" mandrel bent exhuast.

 

Krivera,

91 Corvettes use an equivalent ECM from the factory.

The ECM is 1227727 for the 90-91 Corvettes, 1227730 for the 90-92 F-body cars.

I believe they use the same mother/daughter boards internally. The Vette however uses a different case and different connectors since it is a weatherproof, underhood version of the 730, which is mounted in the interior.

The Vette also uses at least one more input (Engine oil temp).

The BINs are relatively close except for the EOT codes that the Vette BIN has and the fact that the Vettes had aluminum heads vs the cast iron heads that the F-bodies had. Differences would be in spark, volumetric efficiency, and injector constant to name a few.

Changing to a 730 would gain you nothing.

 

your right :thumbs: :iagree:

One Q though... the 92 F body's had iron heads??? hhhmm learn something new every day.

 

Another Q .... i forgot to addd in... Did the 90-91 Vettes use a MAF??

 

Fast-

The 90-91 Vettes used a MAP sensor only.

Re the iron heads...I am under the impression that 3rd gen F-bodies had cast iron heads until they came with the LT1 in the fourth gens. Honestly haven't looked into it though so I could be wrong.

 

that is a good question... I know the 90-92 F's used engine code L98 too.... so maybe it is alm heads..and they made 245 over our 240HP. Whatever...lol.