Running Issues with Howell TBI

[SAR Jeeper]

A couple of months ago, I installed the Howell TBI into my CJ7. I have the 258. It is the JP1 kit, 50 state smog legal.

After install, all was great. Ran excellent. Not a single issue. After buzzing around town for a few weeks, I (and a few others from MJR) went to Millers.

One the downhill portion of the trails, I was flooding out. We would have to disconnect the injectors to clear the flood. Performed flawless on the climbs, tons of low end power. Because I'm running 35's with 3.73's, I don't have a great crawl ratio, but I could pull it from a bog to full throttle quickly and with no problem.

On the road down Millers towards Hungry Valley, I noticed it "stumbled" on right hand turns. Freeway trip home was problem free, except I got a code 45 (running rich).

I still "stumble" on right hand turns. Runs flawless straight, left, backwards, until I turn right. Driving me nuts.

Now I'm starting to get hard starts on a cold motor.

I cannot find what is causing this.

I've been posting on CJ boards, but haven't yet found a solution.

ANY idea's!?

Thanks in advance.

[Kodiak Spirit]

3 left turns do make a right...

[SAR Jeeper]

I would, but my left turn signal ran out of blinker fluid, so I can't turn left either. Thanks though!

[Dave84cj7]

SAR Jeeper,
I've got the same kit on my 84. I am also getting code 45. Some times get the flooded symptoms and have a tough time starting it when its hot. Holding the pedal to the floor should signal the computer to shut off the fuel until the flooded condition clears and it will start. Sometimes have to let it crank a while though. It could be that the return line from the throttle body back to the tank is plugged or too small causing the rich condition and the code 45. Thats the direction I'm leaning with mine but I haven't had a chance to verify it yet. As far as the right turn thing thats a weired one. Good Luck and let us know how it turns out.

Dave

[RAT]

Just a thought; have you checked to see if you have a wiring issue causing the right turn stumble? You may have a short, a wire broken or rubbed through and grounding on something when you turn right.

[SAR Jeeper]

I checked my return line pressure and it was 5-6psi. Howell says it's marginal, but acceptable. Just to rule it out, I ran a 5/16" fuel line into a can in the Jeep, and it had less than 1 psi. It still stumbled on a right turn.

I checked for any wild wires, and shook the wires of my ignition, TBI Harness, and could not get it to stumble. I was going to trace EVERY SINGLE wire today, but I'll have to wait for the rain to stop (at least the rain will open some of our off-road areas!!!) I had discovered a lot of unknown wires when I removed my old computer. One thing that was on my to do list was to clean up all the wires for the electrical system (I have about 3 that are just hangin loose...1 of which was a hot wire).

I have checked my manifold vacuum, and it was 18 inches at idle, and 19 at 2000 rpm's.

Also, my input fuel pressure measured at the TBI is 12psi. Normal is 9-15psi...so it is right in the range.

[RAT]

I hate those pesky Gremlins. When you find out what it is you usually smack yourself in the forehead. Does your Jeep have in-tank fuel pump? possibility that maybe the pick up is getting blocked by debris somehow? Is the flex line from the tank to the hard line connection at the frame getting pinched somewhere? I'm wrackin' the grey matter here...

[SAR Jeeper]

The kit came with a fuel pump that is mounted above the skid, on the frame rail. I had new hose run from tank to hardlines last year when they became so soft they were sucking themselves shut. That started in Goler Wash (Panamint Valley), and had to limp her home.

I'm hearing more and more that it's gotta be electrical. So when this rain stops I'm gonna trace every friggin wire in the engine compartment.

[dirtman13]

This may be a stretch but is the gas tank stock? I believe that most if not all fuel-injected vehicles have baffle in the tank that prevents the gas from sloshing around when turning. On a carbureted vehicle it really doesn’t matter because of the gas in the float bowl. It’s a stretch but I have heard of vehicle having the same symptoms that didn’t have baffles in the tank. Especially if the pick up tube is on the far side of the tank. I have fuel injection and baffles in my tank.

[Dave84cj7]

SAR,
Don't know if this would work but might be worth a try. Run some wire from the connections on the fuel pump into the cab and put some sort of a test lamp on it. That way you could see when the pump is getting power and when it isn't. Take it out and drive it and turn right and see what happens. Hopefully it would show whether or not the power to the pump is being interrupted.
Dave

[SAR Jeeper]

As I said in my first post, I was getting hard starts on a cold motor. I now cannot keep it running without giving it gas, or it'll die. It reminds me when I first did a complete tune up and put the plug wires in the wrong order on distributor. It'll run, but piss poorly, and it would die if I let off the gas. I haven't touched my wires, so something else changed. I'm wondering if my ignition module or distributor is failing.

Unfortunately, I can't work on it until Monday.

Dirtman...to test that, I filled my tank full, and I still got the stumble. If I had issues at 1/4 tank and not at full, I would suspect that.

My grey hairs are getting grayer! Ugghhh!

[RAT]

My grey hairs are getting grayer! Ugghhh!

I've been reading the install instructions and other tech info at the Howell site. There are at least two ground wires, one on the distributor and one on the ECM. Have you checked them to make sure they're tight? And what kind of wire splicing peices come with the kit? Are they 3M Scotch-lock types? If so, I use them all the time and they are notorious for not cutting all the way through the insulation of the wire when you crimp them. You might want to go back and re-check all the splice connections, if you haven't already. I suppose your on the phone with the tech guys at Howell.
Kurt

[Mitch]

Ok Steve,

You've got my attention. My new Howell was installed on my new 258 motor a couple of months ago, and at first was 100% perfect. Then it started running so rich on a cold start that it will barely idle. Once the motor is warming up (over 140-150 degrees) it will run good great. I've had 4 different times that the Jeep wouldn't start and I had to put the pedal to the floor and it started right up.
As it gets colder in the mornings and the Jeep cools off faster when stopped on a run this is becoming a pain in the #SS! My call to Howell wasn't of much help, but they did say to check the ignition system. I have not had any issues on the trail (uphill or downhill) other than the cold starts.

Mitch

[SAR Jeeper]

About my grounds...the harness ground was to be bolted to the intake manifold...instead I ran it to the block (passenger side, down low).

I was talking to my brother-in-law tonight...he is a Ford Mechanic, and use to be a Jeep Mechanic. He came up with some good possibilities. He feels it is probably a grounding issue. He said quite often the ground from block to body or frame will corrode, but there will not be much "notice" because the block will usually ground itself at the motor mount. If on a right turn, the motor shifts just enough to release the "ground" at the mount, it'll cut out the sensitive TBI.

I don't work until late tomorrow, so I'm gonna spend a few hours on it. I have a mechanic friend coming over to help. All fingers crossed on both hands!

[fun4wheelerguy]

That diagnosis sounds really good and logical.

Brett