Howell TBI install tips

[Dude]

OK, today I went and cranked it up after three weeks sitting in the sun and there was no gas in the carb.

I've ordered the Howell TBI kit. For those that have installed it already, I have a few install questions before the kit arrives.

1. Fuel pump location? Drivers frame rail?
2. Gas tank mods. I have three lines to the tank, but now only need two, which one would you cap?
3. What fuel line did you use for the high pressure portion?
4. Did you leave the mechanical fuel pump?

If you have any other tips that would ease the install, I'd appreciate it. Looking to drop the tank and clean it as a precaution. With that, I'm hoping to spend no more than 6hrs on the install, assuming a good program.

Oh, and they said the GM350 throttle body would be sufficient for the engine - Edelbrock Peformer intake, cam, headers, Jacobs ign. Is anyone running the GMbig block throttle body with a similar config?

Thanks

[Elliott]

I can address a couple of your questions. The return line you'll be blocking off is the one that returns from the fuel filter which you can trace back. Pull the fuel pump from the block and use a GM block off plate (big block IIRC). It's always a good idea to clean out a fuel tank, be sure to clean the filter sock inside the tank also.

[xupe45tgp]

I just installed one on a CJ7 and it came with the block off plate and the fuel line. The only thing to buy is an air cleaner. It only took about 8 hours to install. make sure you put your ECM in a place that no water can get to it even when you are washing ou the inside (and yeah thats from experience)!!!!

[rmorit01]

I just installed one on a CJ7 and it came with the block off plate and the fuel line. The only thing to buy is an air cleaner. It only took about 8 hours to install. make sure you put your ECM in a place that no water can get to it even when you are washing ou the inside (and yeah thats from experience)!!!!

Also, on a waggy or Cherokee think about where the heater blows on the ECM module -- on my chero it certainly blows a ton of hot air in the winter and there wasn't a whole lot of room on the driver side -- see if you can mount the ECM on the passenger side, since some folks have done this.

[byson1]

I just installed one on a CJ7 and it came with the block off plate and the fuel line. The only thing to buy is an air cleaner. It only took about 8 hours to install. make sure you put your ECM in a place that no water can get to it even when you are washing ou the inside (and yeah thats from experience)!!!!
Have you been happy with the results?

[Dude]

2. Three lines. One vent to the charcoal canister, one return from the tb, one supply. You need all of them.
3. Regular FI rated hose and clamps. You can use the existing hard lines for most of it. Remember to put a filter before the pump.

Tips would be to make sure you have the proper adapter plate for the TB, and if you want to minimize downtime, run all the wiring and sensors one weekend then do the fuel and TB the next.

OK, thanks for the heads up on the time frame. I'm assuming a good kit.

If the charcoal cannister is gone, what else make a suitable tank vent configuration with an electric fuel pump?

What pre-pump filter do you recommend. I've only seen a pickup sock and a discharge filter on any other FI engine?

The Howell guy said the Edelbrock manifold does not require an adapter plate. I thought this was odd being that the TB is a two barrell. What gives?

Thanks again!! And I will let you know how it works.

[Dude]

I just installed one on a CJ7 and it came with the block off plate and the fuel line. The only thing to buy is an air cleaner. It only took about 8 hours to install. make sure you put your ECM in a place that no water can get to it even when you are washing ou the inside (and yeah thats from experience)!!!!

Howell said the stock air cleaner assy would fit on the TB. Did yours not fit? I guess I don't need the hot air to the carb anymore, right?:eek:

Thanks again!!

[xupe45tgp]

the kit is great. howell is talking about the stock air cleaner from a throttle body pickup (at least that was my understanding)

[pb]

If the charcoal cannister is gone, what else make a suitable tank vent configuration with an electric fuel pump?

If it makes you feel any better, I don't have a charcoal cannister on mine and I have no problems as of this time. My wagon didn't have one when I got it and I only have two line connections on & going to my tank.

[Dude]

OK, got the kit in the mail and did a complete inventory. Looks like everything is there except for a few ring terminals and butt connectors. Oh, and they really should throw in a fire extinguisher too.

The clock starts tomorrow when I get the bung welded on then throw her up on the blocks.

Anyone want a Holley:sawzall: ???

[xupe45tgp]

what holley is it???

[Dude]

OK, got it running and the Howell program appears to be VERY close to what the Holley was able to do, sans long starts, boil off, and sticking needle valves. Driveability is much better.

The Howell harness is universal and NOT FSJ specific. Instead of running the EFI harness next to the existing harness, I married the two and added and cut wires as necessary. Many wires had to be lengthened. I found butt connectors more useful than putting a Weatherpack connector in a wiring harness.

With the plumbing and elec squared away, I spent about 3 hours back and forth with Howell about the tach signal input to the computer. When using an aftermarket multi spark module (Jacobs/MSD) the white wire does NOT go to the neg side of the coil as the instructions suggest. Once that was corrected, it fired right up.

You can use the existing air cleaner and throttle and kickdown linkages. Had to grind flat the TB lever attachments. I ground them flush to the lever arm and drilled the throttle linkage to allow uninpinged idle connection and full WOT at 1.5" from the butterfly fulcrum and the kickdown at 1.25" from the fulcrum. This allows a good ratio between applied throttle and transmission operation for my setup.

The biggest delay was the gas tank. I had always suspected that this vehicle had been submerged or driven on red clay roads. When I dropped the tank, it was in a mud brick sarcophagus that must've weighed 50lbs. When I pulled the sender unit, it fell apart from rust. Thanks to BJ's for a quick delivery.

Will report gas mileage results once I get a couple of tanks through it.

[Dude]

[quote=The Anti-riced]Dunno what to use instead of a charcoal canister.
Tell the Howell guy to stop bogarting the bananas. :alc: The GM TB is a three bolt two barrel. I have a Performer non-egr on mine and I do have an adapter. I made my own, but I think Holley 17-45 is the right number for a squarebore to tbi adapter. Available at Summit or Jegs. Stay away from the Trans-dapt adapters.

The stock air cleaner will work fine, even with the performer. Heat is a good thing as TBI is a wet system and it's still possible to ice up.

[quote]

Howell supplied the adapter and fuel pump block off plate.

The only ice we have here is found in close proximity to beer:alc:

Tks for all the advice and help.

[Dude]

Also, on a waggy or Cherokee think about where the heater blows on the ECM module -- on my chero it certainly blows a ton of hot air in the winter and there wasn't a whole lot of room on the driver side -- see if you can mount the ECM on the passenger side, since some folks have done this.

Mounted it in a slot above the left side of the brake pedal that was peculiarly free of a bird's nest. Just barely made the A/C fan speed resistor conns, though.

[FSJ Guy]

Your mileage won't improve any. You'll be so giddy with the "like new" condition of your motor that your foot will always be buried in it. :D

[Dude]

OK, something is still wrong with the ignition system.

I have a Jacobs FC1000. I told Howell about this and they incorrectly advised that I connect the tach signal (white wire) to the coil. I have since connected it to the Jacobs tach output and am having a problem. When it is cold it will not give a signal below 500rpm. Called Jacobs and they said that was correct and how the unit was designed. I have read elsewhere that some TBI kits come without the tach filter when using aftermarket ignition systems and the tach output from that system. Once the engine is running or still warm, it starts and runs fine.

Also, I am using the existing Duraspark box to trigger the Jacobs unit. The Duraspark box is putting out 4.2v to the coil with the key on and 7.1v while running. I am thinking that the Duraspark box is going to ground more than it should. It gets pretty warm. The Haynes manual says it should be getting 12V.

Any suggestions?? Thanks.

[Tripwire]

When I installed my howell system with a MSD ignition A special "filter" was required. The filter is located about six inches back inside the ECM end of the Harness. there are 4 wires which must be spliced in. IMHO you should be soldering and shrink tubing all your connections. IIRC you also have to insert a new pin into the ECM connector for the other signal.

Call Howell and if you need the Filter they will probably send it to you for free

Tripwire:drivin:

[FSJ Guy]

If you're using the duraspark box to trigger the other coil box, you can use the duraspark trigger to fire the Howell. Call em and tell em that's what you want to do and they should be able to walk you through the install.