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Installed a Holley TBI yesterday...have a question

stallion85

stallion85

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There is a temp sending unit that installs in the intake for the fast idle on the TBI. I have a plug on my Edelbrock performer, but the threads are bigger than the sensor. Is there an adaptor that I can screw this sending unit into or do I need to find another one?

Also the radiator hose on the top goes right over it, I am going to have to get a straight neck spout for the intake. I did think about disconnecting the heater and using the hole on the other side. Could I just plug the water pump that feeds the heater core and be ok?

Thanks for your help.
 
I just ran into this problem last month when I installed the Holley Projection unit. I went to a hardware store and used a 1/2" to 3/8" brass adapter. I also have a different thermostat housing from a 89ish chevy V8 that I am going to use to get the radiator hose away from the sensor. The only other problem I ran into was the Vacuum line routing. My line from the vacuum booster used to go to the back of the carburator. When I switched to the TBI, I had to make a tee out of brass fittings to plug it into my manifold next to the distributor.
Hope this helps.
 
I got the vacuum line thing squared away, thanks for the heads up on the adapter. Also, how long did it take to tune yours? We gave up last night after 8 hours of installaton. We fired it up, it ran so rich I was gagging off the exhaust...lol. We started to adjust the TPS, but gave up after having problems with the ohms meter.
 
I just adjusted the knobs right in the middle, primed it, then turned it on. It ran very rich the first two times I ran it (from priming it), then it slowly got better from then on out. It is hard for me to remember not to depress the accelerator pedal before I start the engine when it is cold. It was needed with a carb, but not now. Now it doesn't run rich as far as I can tell (or smell) and I have been running it this way since Christmas. I think that the biggest adjustment for richness was the accel knob. There is a sweet spot with this and takes some patience. If it is still rich, then you may have to turn down the fuel pressure regulator. Let us know how it goes. I found that with this install the engine woke-up a lot. It doesn't feel like a heavy vehicle anymore.
 
Great news on the power gain. I will read over the instructions tonight some more and use some of your tips. Thanks for checking back. I will let you know how it goes:)
 
stallion85 said:
Great news on the power gain. I will read over the instructions tonight some more and use some of your tips. Thanks for checking back. I will let you know how it goes:)
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Well today I got a straight throat water spout ($13) for the intake from Napa and the adaptor for the temp solenoid ($3). Then realized that the upper rad hose would not work. I was hoping it would bend enough, but it wouldn't without collapsing. So off to Autozone since they are right accross the street from base. I looked through all of there hoses and nothing would work. So then I headed down to carquest, no luck there. I sucked it up and drove the 15 minutes to Napa and got a flex hose that fits in real nice.

I also cleaned up and secured the wires going to the fuel pump and put some wire wrap around them.

By the time I was done with all of that it was time to go to work. My bud Trevor is coming over tomorrow to help me tune it in finally:doah:

After that I need to hook up my new Ford shock towers and Gabriel shocks for some wheelin this Saturday. I hope I don't run into any problems out on the mountain:crazy:
 
If this is a GM type tbi system, that is a coolant temp. sesor and is one of the main sensors for the fi. to work. Fuel injection on domestics don't have a high, cold idle. To keep parts reaplacement simple down the road, I would just drill and tap a new hole fore the coolant temp.sensore. If you your talking about aftermarket fuel injection, disreagard all prevoious stuff.
 
perfect timing, My job has landed a HOlley projection Di system in my lap with the projection intake all wiring, distributor, cables to computer software, sensors, etc. It had been installed in all things a 78 3/4 long wheel base GMC van, before we shipped it to pick n pull one of my co-workers wanted to look at the engine since he needed one, we pulled the K&N air cleaner off and both started scratching our head asking who the heck would do this. He didn't want FI so I snagged it, yes it's legal. I manage a tow Company and it appears either the fuel pump relay or the ecu relay went out and they left it sit on the side of the road and didn't come get it from us. Had it hooked up to a battery charger and the PC the other night and everything pretty much checks out. BTW I learned the hard way that O2 sensors actually heat up when hooked up (blister popped today). Anyway couple questions, I'm installing this in a '73 K5 and curious to know how ya'll ran the return line to the tank run a t in the vent line going up to the cap? extra hole in tank (location?) A t between tank outlet and pump? I already have my tank out as It needs cleaned, sealed and painted adn figure I will go ahead and prep it for the FI while i have it out. There is also one connector that I haven't figured out yet on the loom. It's a five position flat connector only 4 positions used grey black red grey wires coming out of it one of the grey wires goes to a round(ish) connector. There are two other wires blue/red and yellow/red that I also haven't figured out yet. I did download the Holley install manual, as soon as we found the unit and have read it to many times to countand can't seem to find these 3 things listed anywhere, though I usually read it as I'm trying to go to sleep so that part might have been smudged by the drool coming out of my mouth after I passed out on top of it. :) I'm sure I'll have other questions but those are the only ones I can come up with at this time

thanks
shawn
 
I will have to look into the wiring part. I have a fuel cell so my return line was pretty easy. So basically I am no help.... :(

Also my FI is the earlier model that does not need to be hooked up to a laptop......


Great score, I paid $400 for mine from a buddy...
 
pumpkin said:
If this is a GM type tbi system, that is a coolant temp. sesor and is one of the main sensors for the fi. to work. Fuel injection on domestics don't have a high, cold idle. To keep parts reaplacement simple down the road, I would just drill and tap a new hole fore the coolant temp.sensore. If you your talking about aftermarket fuel injection, disreagard all prevoious stuff.
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Aftermarket Holley projection:wink1:
 
Finally got this thing tuned in. Boy does the throttle respond now! :)

The Q-jet would throttle up so slow it seemed and now the tach dances up to 4G quick. Can't wait to test this thing out!
 
Sounds like you got it running well. Where did you end up hooking the return fuel line at? Did you have to use that extension piece for the throttle linkage? I found it to be way too sensitive without it. Does it still run rich?
 
just for future reference, that adapter is called a pipe bushing... :D
 
I ran the return line with some rubber fuel line right down to the metal line in the frame. I don't know about the pipe bushing thing your talking about, I bought this kit from a friend and don't think it was included.

I ran into a problem I believe to be vapor lock. The rig was running fine until I topped a waterfall. It shut off and would not restart. There was no fuel to the injectors, but the pump was operating. I let it sit for an hour and it fired back up and ran??

Does anyone know of a way to keep these rubber lines from getting vapor locked?

The return line and issue line are ran from the intake down the front of the block to the stock lines. The issue line has a metal line from where the original fuel pump was all the way to the top of the manifold where it connects to rubber line and then the TBI.

Thanks
 
my 73 tank isn't set up for a return line, I don't think the tank or the pump were I'll have to check though probably wont be able to in the near futuer as the bad weather is keeping me busy, I love icy roads and lots of snow/mud keeps my paycheck healthy. I'm not sure about my 75 parts-mobile I'll have to check I Know the 75 was a federal emmission and not CA
 
I ran into a problem I believe to be vapor lock. The rig was running fine until I topped a waterfall. It shut off and would not restart. There was no fuel to the injectors, but the pump was operating. I let it sit for an hour and it fired back up and ran??
Click to expand...

I do not believe it has been hot enough around here lately for vapor lock. What you describe also sounds like maybe the fuel pick-up line in the tank may have stopped picking up fuel. This would give you the same problem where you could hear the fuel pump working, but there was no fuel at the injectors. Were you at an extreme angle when it shut off, and then rolled it back to a lessor angle when you tried to restart it? My guess is that if you updated your truck from an originaly carbureted engine to a TBI, there had to be some type of fuel tank/fuel pump update or modification as well? You may want to look into this.
 
I am running a 22 Gal JAZ fuel cell. The tank was completely full. It stopped on pretty much flat ground after a decent waterfall climb. The pick up is moved to the center of the tank. There is no way it couldn't have been submerged. I thought maybe the heat from the engine vapor locked the fuel line?? I am stumped??
 
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