Howell Odd Fire V6 Fuel Injection Kit Install

Initial drive across town and back felt promising.....Dog had to go to the vet for annual checkup.
While waiting for the vet I rewatched the latest video. Block Learn numbers seem to remain in the low 120's while the integrator number is up around 128.
Now that the throttle plate is open a tad and stabilizing the Idle....... Maybe I could try backing the fuel pressure down a couple PSI (currently at 17) and see if that lowers my idle speed a hundred rpm or so. Might even stabilize the idle more as it would not be over fueling??? Were "Learning" together I hope....

 

Eagerly awaiting the sorting this out fully. So I can rip off everything for my own benefit

 

Did you ever hear anything more from Howell after last Tuesday's conversation? I was wondering if there were any suggestions from them.

I don't think I would be willing to lower the fuel pressure without fully knowing if the engine is running rich or lean at higher rpm's under load. If you recall, the fuel pressure was raised because of the extremely lean condition you were experiencing when it was set at 12psi.

 

Howell's main tech guy (Troy) will be back on Monday.
I have been playing with the timing some more. Something that has thrown me for a loop was the change to HEI distributor while trying to dial in the TBI system. I would say that the TBI can't function properly without the HEI/ timing dialed in and visa/versa.
A sack of potatoes hit me in the head yesterday morning......
My old Delco/Petronix setup was running manifold vacuum for the advance. The engine was timed to 5 degrees base at idle, mechanical advance brought it up to 21 and vacuum to 35. When I installed the HEI the vacuum line was too short to reach the rear of the manifold so I stuck it on the front of the throttle body... not realizing that it was connected to ported vacuum.


Any throttle plate adjustments would cause timing to increase/decrease which sent me chasing other issues.
Once I hooked to full manifold vacuum the timing advanced to 45 degrees when revved up...... causing a slight misfire. I removed the advance can and through a few trial and error tack welds I limited the vacuum advance travel to 34 degrees total.

The idle is better.... but I still have to keep it a little high... 800-900 range. This is the main focus right now.

 

What is the desired idle speed? This the idle speed that the ecm is calling for. Might be a topic to discuss with Troy.

 

This is what I am hoping to find out.

 

I'm thinking you are still running lean all the symptoms you are describing are lean conditions

 

That's what I'm thinking.

 

Saturday afternoon we loaded up to scout deer outside Cedarville ca.
The trip was 180 miles, 3hrs 17min. I did that drive on 10.5 gal of gas driving 65-70 most of the way. 17.1 mpg.....
The jeep still felt lean and was running warm. Saturday morning while coffee was brewing I hooked up the scanner; found the Block learn numbers in the mid 130's and integrator to be 128. I assumed that this meant that the block learn (long term a/f ratio) was lean and the integrator (instant a/f ratio) was compensating for it.
I increased the fuel pressure to about 21psi, 1 turn on the regulator adjustment, and the idle smoothed out pretty good. The O2 sensor counts picked up to as high as 9 at times. The rest of the day the jeep ran great, idled a tick high but smooth. The water temp dropped to acceptable levels as well.
The drive home went well with the engine running 180-185 at highway speeds in the mountains. Once we got back into the valley and 103 degree temps it ran about 195.
I was really pretty happy with how it ran considering the frustration that I have had.
Here is a video of the numbers and idle in our camp. Doesn't everybody carry a scanner in their jeep?

 

That's good news, so the question is why was it running lean.
Is there a vacuum leak or are the calibrations in the prom to lean?

 

The only place there could possibly be a vacuum leak would be at the intake manifold/ cylinder head Gasket.

 

Intake manifold at cylinder head, Throttle body to adaptor plate, Adaptor plate to manifold, missing or loose vacuum plug, vacuum advance, anyplace their is engine vacuum.
I use propane or a smoke machine to find vacuum leaks, here is a pic of my propane set up it allows me to get into tight places. Back the fuel pressure down to where it was and apply the Propane around the areas that could be leaking, look for the engine to smooth out and RPM's to possible increase. Just be careful there some risk using the propane.

 

I have replaced and greased both the throttle body to adapter gasket and adapter plate to manifold gasket.
The manifold had 3 vacuum nipples that were capped off. I replaced those nipples with solid plugs.
I cannot find any exterior vacuum leaks at the intake to cylinder head. I threw a torque wrench on the intake to head bolts to verify that they were all tight. The only possible thing it could be is a vacuum leak into the lifter valley. I have intake gaskets on order and will change them in the next couple days. I honestly don't believe that there is an intake manifold leak. I will inspect the manifold for any cracks or damage while it is off, but I doubt that there is an issue with it.

Other than this I can only think that there is something wrong in the Prom, or the injectors are sized for the 2.8L/3.1L engines.
If the intake gaskets don't solve the issue I will contact Howell and ask why it needs so much fuel pressure.
Perhaps the Prom is burned for too lean at idle? Just for experimentation I lowered the fuel pressure to the "proper" 12 psi. Within 2 minutes I got a code 44 for lean condition and the scanner mixture numbers went into the 130's/low 140's.

 

I doubt that you will find a vacuum leak no matter how many more gaskets you replace. The simple test and tool that Mjragan noted should have been more than adequate to determine if there was a vacuum leak.

You have good trouble shooting skills. You took the information on how BLM and INT is used in the code and determined during your last trip that an increase in fuel pressure could and did improved the engine operation. With that data and results of the vacuum leak test, your first step should have been a call to your contact at Howell to discuss these finding rather than tearing into the engine.

You are also correct that an adjustment in the code that is stored in the Prom and/or different fuel injectors could affect fueling and allow for a lower operating fuel pressure than that you now need. As far as 12 psi being the "proper" fueling pressure, I doubt that you can cast that in stone. Yes GM used that pressure when installing this system on the engines they designed the system to be used on. Your engine is not one of those therefore a change in psi is not entirely out of question although I am surprised you need 21 psi. Call your Howell contact before doing any more work to the engine. You may find they tell you to leave things as they are.

 

I'll give that a try.

 

Why would increased pressure make a difference in a lean condition? Could it be that the injectors are designed to work at that lower pressure and volume and by increasing the pressure you're forcing the injectors to work beyond their design limits to add more fuel? Would this point to injector orifice being too small or possible the injector program not allowing enough time to add fuel?

At this point your issue is Howells problem to solve. This kit was not cheap. They advertise their kit to work on this engine, so it should.

 

I talked to Troy at Howell again. I explained that my next step was to replace intake gaskets... but that I doubt there is a leak and I was getting a little frustrated. All spark plugs look the same and if there was a leak, that plug would be different.
I asked him to dig up the dauntless program files for target idle. The chip idle is 850 rpm.
Troy explained that he had to set the idle at 850 to smooth out the odd fire tach signal.
850 is higher than I like but if that’s necessary because of the odd fire I can live with it.
But wtf, why wouldn’t that be somewhere in the instructions? I’ve been trying to set idle for 650-700 like with my carb.
He liked the current integrator number at 128, but the block learn of 120 was richer than necessary.
Troy appreciated that I had been on several long trips. He finally offered to burn a new chip with a richer mixture below 2000 rpm in hope of lowering the fuel pressure and mixture while cruising on the highway. I might get even better mileage???
I am going to do an IAC reset at an base idle of 725-750 and see how it does.

 

Do You have a Pcv valve?

 

The fuel pressure controls the volume of fuel sprayed from the injector. It sounds to me that the computer doesn’t know how much fuel is being sprayed. It simply tells injectors to spray based on tach signal rpm. O2 sensor reads the mixture and evens it out with the IAC.
Increasing the fuel pressure causes the injectors to spray more fuel.

 

Yes, pinch off the hose verifys it is functional.