1990 GMC EFI 385 CID stroker

[JimmyRon]

Hello, I'm new to tuning ECMs/PCMs and just joined this forum. I have a 1990 GMC Jimmy, 385 CID stroker w/MPFI conversion to my 1227747 ECM. Edelbrock 2209 Hydraulic Roller Cam, Shorty headers, Edelbrock MPFI intake manifold (http://rd.bizrate.com/rd?t=http%3A%2F%2Flink.mercent.com%2Fredirect.ashx %3Fmr%3AmerchantID%3DZoroTools%26mr%3AtrackingCode %3D390276AC-16A3-E411-B866-B8CA3A5D9DDA%26mr%3AtargetUrl%3Dhttp%3A%2F%2Fwww.z oro.com%2Fchampion-manifold-intake-z1588%2Fi%2FG8688635%2F%253futm_source%253dmercent %2526utm_medium%253dcse%2526utm_campaign%253dshopz illa%26szredirectid%3DSZ_REDIRECT_ID&mid=257468&cat_id=22000200&atom=10681&prod_id=&oid=6139118695&pos=1&b_id=18&bid_type=0&bamt=a5fedf14fd8fec0d&cobrand=1&ppr=7ef1c3d71f94889f&af_sid=76&rf=af1&af_assettype_id=10&af_creative_id=2912) conversion (3201). Heads have been cleaned up, 2.02 intakes 1.6 exh. The conversion uses the TBI throttle body (http://rd.bizrate.com/rd?t=http%3A%2F%2Fwww.partsgeek.com%2F69qsfdv-chevrolet-avalanche-throttle-body-spacer.html%3Futm_source%3Dshopzilla%26utm_medium% 3Dpf%26utm_content%3Dpc%26utm_campaign%3DPartsGeek %2BShopZilla%26fp%3Dpp%26utm_term%3DChevrolet%2BTh rottle%2BBody%2BSpacer&mid=192248&cat_id=22000200&atom=10681&prod_id=&oid=1985301186&pos=1&b_id=18&bid_type=0&bamt=a5fedf14fd8fec0d&cobrand=1&ppr=6c13461485dd6803&af_sid=48&rf=af1&af_assettype_id=10&af_creative_id=2912) for TPS and IAC, the stock injectors and regulator are removed and a block off plate installed. I opened the intake and smoothed the plenum to adapt the larger BB throttle body (http://rd.bizrate.com/rd?t=http%3A%2F%2Fwww.partsgeek.com%2F69qsfdv-chevrolet-avalanche-throttle-body-spacer.html%3Futm_source%3Dshopzilla%26utm_medium% 3Dpf%26utm_content%3Dpc%26utm_campaign%3DPartsGeek %2BShopZilla%26fp%3Dpp%26utm_term%3DChevrolet%2BTh rottle%2BBody%2BSpacer&mid=192248&cat_id=22000200&atom=10681&prod_id=&oid=1985301186&pos=1&b_id=18&bid_type=0&bamt=a5fedf14fd8fec0d&cobrand=1&ppr=6c13461485dd6803&af_sid=48&rf=af1&af_assettype_id=10&af_creative_id=2912) assembly for more CFM. I also replaced the throttle lever with the SB lever to retain the 700R4 (4L60) TV cable. I have Tuner Pro RT and have never tuned an ECM before. I can use all the help I can get. I do understand how the systems work, just haven't done any tuning and not familiar with the terminology. I am hoping to get some direction and advice for the files I need to map this thing and make it sing. The engine is built for dependability and moderate performance. The injectors have been upgraded from 19 to 29 #ph and the fuel pressure (http://rd.bizrate.com/rd?t=http%3A%2F%2Fconnexity.pgpartner.com%2Frd.php %3Fr%3D23402%26m%3D704179010%26q%3Dn%26rdgt%3D1444 834546%26it%3D1445007346%26et%3D1445439346%26price ret%3D42.75%26pg%3D%7E%7E3%26k%3D0ed952ef5d97dafb5 cf94ca0836fce93%26source%3Dfeed%26url%3Dhttp%253A% 252F%252Fwww%252Eeastwood%252Ecom%252Ffuel%252Dinj ection%252Dtester%252Ehtml%253Futm%255Fcontent%253 D1067960%2526utm%255Fcampaign%253Dnextagsean01%252 6utm%255Fsource%253Dpricegrabber%2526utm%255Fmediu m%253DMerchant%252DCentre%2526SRCCODE%253D1SE1530% 26st%3Dfeed%26mt%3D%7E%7E%7E%7E%7E%7E%7E%7En%7E%7E %7E&mid=296470&cat_id=22000200&atom=10681&prod_id=&oid=6482469829&pos=1&b_id=302&bid_type=0&bamt=c2fec4801cf73b20&cobrand=1&ppr=9292207dc9bf22f2&af_sid=19&rf=af1&af_assettype_id=10&af_creative_id=17303) will be regulated at 45-50 PSI. Anyone willing to help? Thanks

[dave w]

:welcome:

Most member here at gearhead-efi.com use TunerPro to tune with. The TunerPro files you need are located here: http://www.gearhead-efi.com/Fuel-Injection/showthread.php?304-1227747-ECM-Information-42

Getting the Chip programmed with the correct Base Pulse Width (BPW) is the first priority!!!!! I've attached an Excel spreadsheet BPW calculator, with an example screen shot showing the BPW using four 29 lb injectors (each Bank of cylinders of the V8 engine). I personally have not programmed a BPW with a value of less than 100, so I would be very interested to see how the BPW actually works out.

Based on an original Edelbrock MPFI chip I read, four 19 lb injectors had a BPW 112. Using the spreadsheet, the BPW with four 19 lb injectors on a 5.7 liter engine comes out to 108. The BPW shown in the screen shot should be in the ballpark when using four 29 lb injectors, or maybe the BPW shown in the screen shot is just outside the ballpark and out somewhere in the parking lot??? (That's Tuning)

dave w