Jeep TBI help

[ricks]

I guess the best way to start is I NEED HELP!!!!.

I just picked up a CJ5 that is running a 360 with a Howell TBI setup on it and I have no clue how to diagnose it or work on it and I would be more than happy to pay someone to dial it in and help me understand how to work on it.



This old school wheeler needs help entering
the 21st century

 

[leadfoot067]

a list of runability issues would help...most anything on that setup can be dealt with with basic tools..

 

[ricks]

It starts and idles fine and will accelerate as long as I don't give it to much throttle, if I gently accelerate it will run up over 5,000 rpm smoothly but if I go WOT or anything more that 1/4 throttle it will start to bog down, there are a couple smaller issues when I try to lug the engine down it wants to shoot the idle up when I need it to stay down low.

 

[zukkev]

timing??? Lack of fuel pressure???

 

[ricks]

I know this is hard to diagnose on line but it seems the problem is inconsistant, when I drive it and give it to much throttle it will start to buck but just sitting there I can wrap the throttle and it sounds good and crisp, then if I mash the peddle to the floor it will run to 3,500 rpm and stay there and sounds like its bogging down

 

[Bunk1]

Easiest thing to do is check for vacuum leaks, they will fawk alot of stuff up if you got em.

 

[ricks]

Maybe I am over thinking things with all the abbreviated terms like ,map,ecm,tps,aldl, temp sensors, o2 sensers and so on, and start with the basics. I will definately check for vacume leaks and fuel pressure first then play with the timing. So my fuel pressure should be at 13psi right?

 

[junkyard jim]

Does it have an O2? The early ones didn't and had major issues. Check the TPS to make sure it's not out of spec.

 

[whatthe?]

Is it a complete howell system or just the wiring harness? If it's complete, you can also look at the prom chip and see what engine it's for just to make sure it's correct. But leaks and fuel pressure, correct hose size, everything hooked up correctly is where I'd start.

 

[ricks]

I appreciate the input, it gives me specific things I can seach the net for,like how to test if the TPS is in spec.

I don't know if it is a complete Howell kit but my guess is yes due to the fact that everything looks new and the ECM has a Howell label on it, also it has been upgraded to a DUI ignition.

This rig is new to me so I don't know much about and I have been researching alot online [binder planet] but for me it's like reading a foreign language, so I will take it one step at a time. I really need to learn how to work on this EFI stuff before I take it out wheeling.


it does have an O2 sensor

 

[whatthe?]

If everything is physically correct and your fuel pressure (good filter) is correct give Howell a call. Troy can help you trouble shoot as well but he will ask you if everything is hooked up correctly and what your fuel pressure is and how you're measuring it. If you can get your hands on a code reader try that, if you're lucky, borrow a scan tool

 

[TreeClimber]

I appreciate the input, it gives me specific things I can seach the net for,like how to test if the TPS is in spec.

I don't know if it is a complete Howell kit but my guess is yes due to the fact that everything looks new and the ECM has a Howell label on it, also it has been upgraded to a DUI ignition.

This rig is new to me so I don't know much about and I have been researching alot online [binder planet] but for me it's like reading a foreign language, so I will take it one step at a time. I really need to learn how to work on this EFI stuff before I take it out wheeling.


it does have an O2 sensor

Binder is the bomb-diggity!

I have this exact same kit.

Mine is on an AMC401. Runs perfectly.

If I was you, I'd find someone with a nice scanner, and start watching the live data. This isn't your O'Reilleys type scan tool, but a SnapOn Solis, or Red Brick, or maybe a Tech1. You should be able to tell what's going on, quite easily.

If you don't have access, then start by pulling codes. Use a paperclip to jumper the wires on the scan tool connecter, and then count the flashes in the check engine light.

No codes? Then I'd start with the ignition side of the equation, and look at the coil, wires, plugs, etc.

If you have access to a fax, I can fax my Howell Manual to you. Or, you can swing by my work in Bremerton.

 

[ricks]

Bill over at binder planet has tons of good info and I have been reading threads all day [information overload].

I am curious about this tach filter I keep reading about because my timing light is telling me my idle is set at 750 rpm's but my tach is reading 1,000 and by ear it definately is not idling at 1,000 rpm's, also I need to see if the DUI has been converted to electronic spark control or not

 

[TreeClimber]

What tach?

Also, Bill is on this website, occassionally. I understand he lives in Oak Harbor. Heck, he's only a hop, skip, and bridge or two from you. Send him a PM on the Binder forum... I'll bet a few $$, and a short drive, and you can get the Master himself to take a look.

 

[reefermadnes]

Fuel filter.Happened to my dads cj5 w/401 and a howell kit.Ran great for years,then started running crappy.No codes or visible issues,changed filter all is good.

 

[ricks]

OK, I could not find any vacume leaks and at idle it has 16" of vacume. The fuel pressure is at 12lb but heres the issue, when I give it WOT the fuel pressure drops to 3lbs. the fuel pressure and the flat spot [bog] seem to go hand in hand, would this be the fuel pressure regulator?

 

[zukkev]

Check for restriction/clogged fuel filter/kinked line...Also, you should see 19" or better vacuum at our altitude, which is essentially sea level, Have you checked the timing yet? Not sure about the howell, but with standard GM TBI there is a single wire that needs disconnected to take the ECM out of the loop before setting base timing...

 

[TreeClimber]

OK, I could not find any vacume leaks and at idle it has 16" of vacume. The fuel pressure is at 12lb but heres the issue, when I give it WOT the fuel pressure drops to 3lbs. the fuel pressure and the flat spot [bog] seem to go hand in hand, would this be the fuel pressure regulator?

replace fuel filter and retest

 

[ricks]

I will start with the fuel filter then test, should it run a filter between the tank and pump and one between the pump and the TBI, when I checked the fuel pressure I removed the filter up top and installed the pressure gauge in its place. I have not checked the timing yet cause I can't see the timing marks with the York compressor in the way, I will have to get some different belts to run it without the compressor for testing but maybe I can cut a sight hole on the inner fender for access. I will do some research on the Howell system to check on the 1 wire disconnect at the ECM for setting initial timing.

I am actually glad this thing is not working right, it is forcing me to understand how to work on it

 

[Binder]

The Howell system is likely fuel only. If your pressure is dropping to 3 psi that is definately a problem. It SHOULD have 2 fuel filters, one before the pump and one after the pump. Make sure and replace them with the correct filters or they will not work.
If Bill gives you advice don't second guess it, just do it. That's over anyone including Howell.