Howell TBI / EFI Installation How-To for CARB E.O. #D-452-2

[babywag]

linkage controls throttle valve in transmission.
controls line pressure/shifting

run without one and trans. will slip, create heat.
clutch packs/bands will wear rapidly.
it'll also shift very poorly.

they can pop off, easy to make it correct, I wouldn't rely on an rtv booger.

[MysticRob]

Huh, good to know. I'm not worried about it falling off, it was still work to get the plastic circular thingee on there, goop was just added measure just in case. I'll look into the solution you provided there though.

[Micull]

Rob - Thanks so much for documenting your install....so helpful. I've just received my kit and will be installing this weekend. Quick question - what did you do with these connectors that plugged into the original carburetor??

20220309_224802 by Michael Cullum, on Flickr

[MysticRob]

Rob - Thanks so much for documenting your install....so helpful. I've just received my kit and will be installing this weekend. Quick question - what did you do with these connectors that plugged into the original carburetor??

The large long curved pipe you have circled on the left is the PCV, which is shown in the diagram I have in post #43. It goes to both port-A and the vacuum canister purge signal nipple.
The one you have circled in the middle isn't a vacuum connection. Take the 2 bolts off and you'll see it's merely a bit of piping that assists in warming the choke a bit quicker than it otherwise would without it. You can actually remove the entire thing, as there are no provisions for it with the Howell kit.

[Micull]

Got it. Thanks.

[Theodore]

Hey, MysticRob, am finishing up an EFI rewire to move the ECM inside & A/C refurbishment & am having an issue with the EFI harness hitting the wiper frame under the dash. Followed your lead with where I drilled the hole in the firewall, and routed the harness toward the drivers side & looped back to passenger side Oslo get the bottom edge of the dash - ECM is mounted with Velcro behind the dash just over the evaporator. Also, sized down the provided wire loom from 1-in to 3/4-in & am still having an issue.

Did you see this? Any tips/tricks?

[Theodore]

Looks like 3rd time is the charm. Rerouted the harness thru the radio area vs near the wipers & it appears to be all good now. Had to relocate the ECM slightly to the left to account for less slack.

[MysticRob]

Hey, MysticRob, am finishing up an EFI rewire to move the ECM inside & A/C refurbishment & am having an issue with the EFI harness hitting the wiper frame under the dash. Followed your lead with where I drilled the hole in the firewall, and routed the harness toward the drivers side & looped back to passenger side Oslo get the bottom edge of the dash - ECM is mounted with Velcro behind the dash just over the evaporator. Also, sized down the provided wire loom from 1-in to 3/4-in & am still having an issue.

Did you see this? Any tips/tricks?

Looks like 3rd time is the charm. Rerouted the harness thru the radio area vs near the wipers & it appears to be all good now. Had to relocate the ECM slightly to the left to account for less slack.

Glad you got it figured out! There isn't much room under the dash on these things for sure. At some point I'll need to get back up under there myself and reposition just a bit as I can occasionally hear the wiper armature scraping the plastic harness loom too. Plus I need to replace the AC hoses to get my aircon back up and running.

[Theodore]

Glad you got it figured out! There isn't much room under the dash on these things for sure. At some point I'll need to get back up under there myself and reposition just a bit as I can occasionally hear the wiper armature scraping the plastic harness loom too. Plus I need to replace the AC hoses to get my aircon back up and running.

True/true. Just got everything put back today. The a/c air box is crazy tight to get back in. Am planning on writing a post on the adventure of rewirng the EFI & a/c refresh - been collecting pix for a post; just never seemed like I had enough of a story til it was back together. Was more of a 2 steps forward & 1 step back til now.

[TomJ]

Missing VSS wiring?

Wondering if anyone else has a harness without a VSS wiring/connector? My kit, same $1600 kit Rob mentions in this thread, came with a VSS and a pigtail to mount to Xfer case, but there's nothing coming out of the main harness for a VSS connection. All the instructions say is, "attach VSS connector to harness." There is no pigtail from the harness for the VSS.



Also, what are people doing about sealing the injector wiring that is supposed to have a rubber plug to keep from sucking in dirty air, where the injector wires protrude through the airhorn?

[MysticRob]

Wondering if anyone else has a harness without a VSS wiring/connector? My kit, same $1600 kit Rob mentions in this thread, came with a VSS and a pigtail to mount to Xfer case, but there's nothing coming out of the main harness for a VSS connection. All the instructions say is, "attach VSS connector to harness." There is no pigtail from the harness for the VSS.



Also, what are people doing about sealing the injector wiring that is supposed to have a rubber plug to keep from sucking in dirty air, where the injector wires protrude through the airhorn?

The VSS is the vehicle speed sensor, and the connector should be part of the longest pigtail attached to the octopus. Check the last couple pics I put up in post #13 for a better idea. I seriously doubt you're missing that one unless Howell screwed something up.

Not exactly sure what you're talking about for rubber plugs where the injector wires protrude through the airhorn. Post #28 has a couple pics of how I routed mine, which is just fine.

[TomJ]

Rob, you're missing the seal in question for the injector wires in your posts. It's a rubber block that seals the rectangular hole in the airhorn where the wires snake up to go to the injectors. That hole is wide open to unfiltered air. Matt finally got back on that question and said they could no longer get the seal from GM and suggest people just RTV them in (no mention of that anywhere in docs though). In other searches, people call it a grommet.


Pic of the part off another forum:





And BTW, no connector for VSS anywhere on my harness.

[MysticRob]

As small as that portion is with the injector wiring I just didn't worry about it. Sounds like you need to return your harness to Howell and have them send you a correctly wired harness!

[TomJ]

As small as that portion is with the injector wiring I just didn't worry about it. Sounds like you need to return your harness to Howell and have them send you a correctly wired harness!

Are you serious? That's a huge air leak into the clean air side of the air horn? Wow. Hope you don't drive on dusty roads, seriously, that needs to be sealed, path of least resistance and all. Howell should have addressed this, having a gaping hole for dirt and dust to contaminate intake air is not a professional product.



Looks like they sent me the offroad harness, but the box is marked for the emission kit:

[MysticRob]

It's an extremely small hole with the wiring going through it, especially compared to the fresh air coming in from the snorkel, so again, I'm not worried about it right now. It's not an offroad ride anyway, so enhance your calm, John Spartan. If it makes you feel better, I'll consider doing something about it someday.
Unfortunately my Howell kit didn't come with that grommet, and searches for it have been unsuccessful, so I'll make do without it for now.