Originally Posted by
X-man
I wanted to take a moment to post my experience with the Flash II with port mod. I have a 94 K3500 that came from the factory with tbi, 5 speed, and 4.56 gears front and rear. The performance and fuel mileage was underwhelming to say the least. With the help of David from Old School EFI I was able to boost performance and fuel mileage but low speed drivability was still not great. David brought up a conversion and was able to locate an intake and injector package for 96 and up Vortec EFI. I found a set of vortec heads and after having the heads checked I installed the whole Vortec top end with the addition of 36lb injectors and a 255lph pump. The original ecm for this setup was a modified 7427 ecm that worked great with the exception of a random hanging open of all eight injectors flooding the engine and keeping the pump running with the KOEO. This occured when priming the fuel system and if you immediately went to cranking the engine you would have never known this was going on. After speaking about this with David and trying to correct the issue I sent an email to Dynamic EFI. The first thing I noticed was a willingness to help on a system they had nothing to do with which made the decision to buy their product alot easier. I purchased a Flash II with port mod and connectors for the ecm and in a relatively short time and help from Bob at Dynamic EFI and David at Old School EFI I was able to get my dually dialed in and reliable. I was also able to accomplish each goal I had for the truck. The truck is more powerful and low speed drivability is incredible and after putting around 600 miles on the new ecm I recorded a best 16.73 miles per gallon checking this buy fuel usage checked at the pumps and not on just the trip program in the WUD. I have gotten to test this new setup in -5 degree weather up to 70 degree weather and in town traffic as well as the interstate. We live in the mountains and this is my four wheel drive vehicle to get us in and out so reliable was extremely important to me. The tuning help from Bob and David as well as the info in the program and on the sight has been second to none. Having tuned quite a few standalone ecms from AEM, Holley, SDS, Fast, and Ecumasters on my Supra I have had alot of dealing with aftermarket systems so it was nice to see this system do everything as advertised. It is nice when you command a change a see and feel it happen on your wideband and seat of your pants dyno. With OBD1 stuff being harder to find I just wanted to say thank you for an amazing product and some amazing help from two great companies. Sorry about the long post and in case anyone is interested the setup is a Gen 5 short block with the stock tbi flat tappet cam, Vortec heads converted to an adjustable valvetrain, Gen 6 intake and Fast 36lb injectors, tbi distributor and Hedman headers with dual 3 inch exhaust. The cam was left in due to covid wiping out all hydraulic roller cams at the time of this build. Truck weighs 6500lbs empty and is a 5 speed with 4.56 gears and 126,000 miles on the truck and bottom end.
Sean
