| Re: TBI Questions & Google Groups [message #369301 is a reply to message #369297] |
Mon, 28 March 2022 23:10   |
rvanwin
Messages: 325
Registered: April 2007
Location: Battlefield, MO
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Jess Bressi Cortez wrote on Mon, 28 March 2022 16:03Greetings all, I have some questions that perhaps you have answers to. I would direct these to the Google Howell group but it is not accepting new members or is without an administrator. The context is I am installing a new to me Howell TBI system with embedded locker on my 455. BTW, I swapped out the Holley TB for a GM from a 454 Chevy.
Question 1: I've tried to obtain access to both of the Howell-related Google Group sites dedicated to the Howell systems. I've received no response to several requests for access rights. Is there no "owner" or "administrator" taking care of them right now? Suggestions?
Question 2: Has anyone used Applied GMC's small surge tank with a FI system? Did you plumb the bleeder valve output with a "tee" to your TB's fuel return line? Did you add a check valve?
Question 3: I have one of Tom Pryor's MB Diesel electronic clutch fan setups sold by Applied. Has anyone used the fan output of the ECM to control a relay powering the MB fan clutch? Any issues?
Question 4: What are folks experiences in the ability of the built-in GM fuel regulator to deal with the higher pressure output of the TBI's fuel pump, example an Airtex 2182? Anyone modify their TBI to make the fuel regulator adjustable or add an external one?
Question 5: Anyone change from a one-wire NB O2 sensor to a three-wire WB O2 sensor? It appears to me I'd just need ot add switched 12v power and ground. Will the ECM accept the WB without re programing?
Many thanks, Jess
Question 1: I think Ken Henderson addressed this issue. I also use to get those notifications but have not been getting those.
Question 2: I do not know of anyone using that surge tank. Should not be a problem to use. Personally, I do not think a surge tank is needed. My approach is to get complexity to a minimum. I always recommend two fuel pumps with each pump having its own filter. That way you always have built-in redundancy. If one pump or filter goes bad switch to the other and finish your trip and fix it when you get home. I've only had a couple of experiences where I had a slight stumble on a corner when I was almost empty in both tanks. One should never get that low on fuel or run the risk of being on the side of the road waiting to get enough fuel to get going again.
Question 3: Yes, there are several using the EBL to control the MB electronic clutch fans. This is a relatively easy hook-up and requires a couple of parameter changes to the programming to set the on temp and off temp.
Question 4: This answer depends on the Throttle Body. If using the Howell system, it has an adjustable regulator. It can become a little temperamental above 18 or 19 psi but can be set to satisfy our engines. The Rochester TB has a fixed pressure regulator and is designed to regulate fuel pressure from a high-pressure pump to the correct pressure for the system. Sometimes the springs get weakened with age - new springs are available. I believe some people have modified the setup to make it adjustable. However, that is usually not necessary because the regulator is set to the appropriate pressure for the injectors used in the Throttle Body.
Question 5: The ECM requires a NB O2 Sensor input for it to properly adjust the fuel mixture. Some WB O2 sensors can provide a NB input to the ECM but I don't recommend that because I don't believe that is as reliable as the NB. A separate WB-O2 sensor can be added and the EBL will display this output on the What's Up Display. Also, the EBL can use WB-O2 sensor input for more in-depth tuning. I find that this is more for high-performance tuning (hot-rodders) and not as effective for how we run our engines. The basic self learn functions using BLM tables that the EBL does for self-tuning is more than adequate for our needs.
Feel free to contact me directly if you have any further questions. I have sent you a Private Message with contact information.
Randy & Margie
'77 Eleganza II '403'
Battlefield, MO
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