Howell TBI

[dannyboysfc]

Hey fellow jeepers, I havent been posting in a while. I am starting my summer project of a Borla header, and Howell TBI. Finally I'll be rid of the cursed Carter BBD.

Any tips from those with experience with these upgrades would be appreciated.

Oh and I have 2 carbs, an exhaust manifold and all that smog crap for anyone who wants to pay shipping or pick it up.

[Bachman]

I ran Howell's tbi on 2 engines...Love the product, easy to install, works perfect. Also the customer service is great.!:thumbs_up

[dannyboysfc]

questions

Where is the knock sensor located on my 4.2?, what is that little thing that has two wires connected to it that attatches near the base of the oil pressure sending unit?

How does the intake manifold heater switch work with only one wire? how would I rewire it if i got ahead of myself and cut out all the wireing and relay that it was hooked up to?

[SAR Jeeper]

Here is its location and a photo of it

http://home.sprynet.com/~dale02/knock.htm

[dannyboysfc]

Ok so I finished hooking everything up and it wont start. I figure ethier I removed too many wires, or something is wrong with the tach signal from my MSD going to the ECM.

Instead of just cutting off all of the old wires at the main harnes like the instructions said to, I decided to follow all the wires from the old ECM and the old diagnostics and remove them. I ran into what I assume is a switch related to oil pressure near the bottom of the oil pressure sending unit and removed those wires as well assuming that it was related to the old computer and I didn't need it. Could I have been wrong?

Other thought is that I may need one of those tach filter thingys to send the correct signal to the computer.

[SAR Jeeper]

The oil pressure switch next to the oil pressure sending unit controls the electric choke...which you no longer need to worry about (I don't think.) I think your new computer will control that on the Howell.

Are you getting spark?

Are you getting fuel? I believe, from reading instructions for Howell (I'll be doing this next March), you should hear the electric fuel pump when you turn on the key. Be sure the fuel pump is getting power when it needs it.

[dannyboysfc]

Well I am getting nice big fat spark, and fuel to the TBI unit, but with the air cleaner off I cant see any fuel squirting down into the manifold. I've cycled the fuel enough to know that there is lots of pressure and fuel at the TB, but it doesnt squirt while cranking.

The only thing that I can think of is the tach signal is bad, I may need one of those tach adaptors from MSD. Although I did talk to a guy at Howell and he told me I didn't.

OH well I may have to wait till tuesday to call back Howell for help. That means no Jeeping this weekend.

[dannyboysfc]

C'mon somebodys got the answer

Well I have determined that the problem is that the new computer is not getting a tach signal from the MSD while cranking. I can trick the injectors to squirt fuel by tapping on the tach lead from the Howell harness with 12 volts, then with fuel in the intake I can crank it over to start it up and it runs great. The problem is that while cranking there is a problem with the tach signal. I bought the MSD tach adapter just to try it and it makes too much signal and floods the engine right away. Howell helped me test the system to determine that the problem was not in the system that they sold me, but didn't offer much help besides that.

[Bachman]

Maybe you need to go back to a stock distributer to get the correct signal. Maybe...

[dannyboysfc]

Well I thought of that, but the guy at Howell told me that my system is set up to run with an MSD. I really dont know at this point, but I dont want to throw away money trying to solve this problem. It has to be something really simple.

[Bachman]

Do you have it hooked up to a switched 12 volt source? When I first hooked mine up It would not spray fuel. However the system was armed, fuel pump pumping, fuel pressure was good, but no starting/ running. It would run though after sprying starting fluid into engine. Once starting fluid had fired the engine the Howell system worked perfectly. I had the 12 volt lead to the howell system on a hot 12 volt source not a switched source. After I switched the wiring it started and ran fine.

[dannyboysfc]

Yeah I hooked it up to one of the yellow wires that are inside the wireing harness, just like the Howell instructions said to. I think the problem is in the ignition system(tach signal). The guy at Howell told me to throw in a DUI ignition. What a solution ehh, another 400 after I just spent 1200 on the Howell. So Im doing the HEI swap from a chevy 250, just have to wait a few days for the drive gear. Ive always kinda liked the HEI 1 wire hookup anyway, dont really care for MSD too much.

[Bachman]

I would still double check hot vs swiched power?. Also maybe missing ground wire?. I would hate to spend more money if it is something simple...

[dannyboysfc]

Yeah, I dont really mind spending the money on Jeep upgrades, but Im not going to give 400 of my cash for a distributor, no way! I got a junkyard HEI for 40 and am waiting on a drive gear to put on it from 4wd hardware for 26 i think. After that and a new cap rotor and plugs the damn Jeep might still not start. :haha: But in the mean time I will try just hooking back up the stock ignition just to see what happens.

If by switched you mean that it is hot during cranking and with the ignition on, then I got it. If not correct me. What power source did you end up using? I am pretty sure I have the right power source, but am wondering if there is low voltage problems at starting. I dont really know much about testing for voltages. But it would be simple enough if all I had to do was run a relay from a switched source to up the juice to the brain.

[SAR Jeeper]

Cheaper might be to go back to stock distibutor, and do TFI mod?