79 Jeep Cherokee, AMC 401, T-18 manual trans, hydroboost, 16197427 MPFI system---the toy
93 Jeep YJ Wrangler, 4.0L, 5 speed, 8.8 rear, homebrew hub conversion and big brakes, hydroboost, 2.5in OME lift, 31x10.50's---the daily driver
99 Jeep WJ Grand Cherokee limited, 4.0L, auto, 2wd, leather and power everything, 99% stock---the long distance highway ride.
As I explained to TOM, the Edelbrock conversion was done some 8 years ago. Unaware of all this stuff when it was done. Worked fairly well. Used Moates APU1 to make changes about which I knew absolutely NOTHING! Still it worked out after capturing the Edelbrock binary supplied on their chip. Also purchased another programmed chip from which to extract data, although I had little idea about what I was doing. Still puzzled as to what the ECU mods really do. Still have not done them and yet the stock, with exception of the flash chip, ECU and Engine run just fine.
Gentlemen: Just to provide some background about myself, I really like working on Internal Combustion Engines especially the Small Block Chevrolet. It is a compact package capable of much horsepower depending on how much a person spends on building up one. I was in Aviation Electronics, known as Avionics, for 38+ years. Electronics is nothing new to me. Yet, getting through TunerPro RT V5.x is somewhat of a challenge. Have read many of the posts here on gearhead-efi. Am very greatfull for this Internet Site as it has been a wealth of knowledge. Many of you fellows have extensive knowledge just through exposure doing your own GM EFI projects. A special thanks to Dave W. as he had been VERY helpful. I have two chevrolet trucks that I work on. One a 1994 BBC Suburban and the other a 1995 Chevrolet C1500 2WD pickup that is in good condition except it leaks and uses engine oil. Am preparing a 350 Vortec and will be using a BBC TBI throttle body on top of a 4 barrel manifold with adapter. Just added a LT-4 Hot Cam to the Vortec and today the stronger Crane Cams valve springs came via UPS. Need to install these and mock up and set the fuel pressure regulator on the BBC throttle body. Then run the Vortec on my home brew run-in stand with a Holley 4 barrel carb. Also have a harness for the 16197427 ECU. Shall see if I can get the harness and BBC throttle body all mocked up on the run-in stand which provides NO dynamic load whatsoever to the Vortec. At least I can check for oil leaks etc. before installing same in the '95 pickup.
It is nice to have you fellow to consult with.
Regards,
Rolly
Tucson, Arizona
if you have a multiport intake and injectors I have no idea why you would want to run them in a tbi fueling mode. ya it'll run but leaves a lot on the table no?
The calibration from Edelbrock runs the 8 MPFI injectors in a batch fire mode , this setup is not a "true" MPFI setup but rather a small upgrade to get the fuel flow from the factory TBI out of the air stream and directly into the ports. The 16197427 will not support true MPFI.
As I said in my earlier post , I tried to use the factory Edelbrock calibration on both my original 454 and the replacement 502 (509) in the '7427 , It ran OK , but I believe it left a lot on the table with the PCM in the original TBI mode. I switched to PFI mode in the PCM (Jumper mod only , no sense resistor mods) and it runs and idles much better.
Just my experience , the OP states his idles just fine the way it is so he should be good to go.
TOM
Last edited by Nasty-Z; 01-22-2015 at 05:21 PM.
1994 3500 Dually , 502 (509) , 264HR , Edelbrock MPFI , PFI '7427
1992 S-10 434 SBC/Tremec - '7427
1986 Monte Carlo SS
1984 S-10 , SAS, 496/700R4/205 , D44/14BFF -'7427
1980 Z-28 496/700R4
1979 Corvette 496/700R4
1977 Olds 98 Regency 403/700R4
By true MPFI I mean sequential , the '7427 will not support this . The normal "TBI" mode is injectors fire every 2nd DRP , the PFI mode I run the '7427 in is every 4th DRP (The '7427 can also run CPI mode which is every DRP). What I experienced in running the PCM in TBI mode with the 8 injectors is that the PW went so low idle quality started to be affected.
I do not know the whole story behind the sense resistor bypass , I was told for the conversion to be 100% reliable it needed to be done , I have over 75K and 10+ years on my conversion on only the Netres mod .
TOM
1994 3500 Dually , 502 (509) , 264HR , Edelbrock MPFI , PFI '7427
1992 S-10 434 SBC/Tremec - '7427
1986 Monte Carlo SS
1984 S-10 , SAS, 496/700R4/205 , D44/14BFF -'7427
1980 Z-28 496/700R4
1979 Corvette 496/700R4
1977 Olds 98 Regency 403/700R4
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