Howell Odd Fire V6 Fuel Injection Kit Install

If you generally like this system but want the added aspects you noted, download the free tuning program TunerPro or TunerPro II. You also can look at ELB. They offer this same ecm that is modified to allow for flash tuning. It is ecm, tuning software with data logging ability, etc. only and not a complete packaged system as offered by Howell.

The wideband o2 sensor does give a clearer picture of the engine fueling. It is a useful tool if you are inclined to do your own engine tuning but not all want to spend the time and effort to go there. Also, it's linear output it not compatible with this ecm.

I'm curious, what is an "OTC Obd1 computer" and how will that help to figure out what is going on? I know there are numerous OBD1 computers on the market but not all are compatible with throttle body efi.

 

OTC is a tool maker brand. He means OBD1 reader. Not familiar with the data stream from the GM computer, but presumably it will tell you something in real time.

 

Agreed. You can add tunability to the Howell, but for the same price the other solutions come with it. That's one of the reasons I wouldn't go with Howell.

Presumably you can see what the sensors are saying. If they are all sane and the fuel pressure is OK, it's likely a tuning issue.

Do agree that the fuel pumps should be in or near the tank and pushing though as much hard line as possible.

 

After last nights drive, I'm not convinced that the problem is fuel pump related. I have constant, proper fuel pressure.
I did however notice that the two injectors don't spray the same.
Here is a little video I took. The drivers side injector (right hand side of video) doesn't have a consistent spray pattern and actually lets a little drip out every now and again. My computer screen is not anywhere near 4K..... and makes it hard to see.... but on the phone screen it is obvious.



I called Howell this morning and they are sending me a new injector. Bouncing ideas off of Troy, he asked what distributor I was using. When I told him a Delco with Petronix kit he recommended changing to an HEI. Troy believes that the HEI gives a better tach signal than the Petronix.
I'm not really sharp in that department...... so I have an HEI distributor on order.

 

It is a scanner made by OTC that is supposed to show the live data that the ECM is reading.

 

I found an excerpt online that seems to back up Troy's statement about quality of tach signal out of the Petronix.
This came from a forum where someone was installing a FAST efi system.

Well, if you use an HEI, you connect the white wire to the HEI Tach terminal. ... It has a tach output that is very solid and will give a much more accurate consistant reading than the negative side of any coil.

 

Good catch on the injector. I wasn't even thinking they could be an issue.

I should have though. When I first put the Megasquirt on the Mustang, I had all sorts of issues tuning low throttle driveability and getting a consistent idle. Turned out the "rebuilt and flow tested" injectors I used had similar issues and could not control the flow consistently at low duty cycles. Installed a full set of brand new Bosch injectors and the issues immediately vanished. I was suspicious of the original ones because the fuel pressure leaked down too fast after shut-off.

 

I picked up a rebuilt Cardone 30-1693 oddfire HEI and all associated parts. The install is a real PITA with my 3 core radiator, fabricated shroud, power steering and oversize aluminum intake....... I need to get a longer upper radiator hose and route the spark plug wires better.
After stabbing the distributor and getting the timing pretty close I took the jeep for a test drive. The HEI seems to have cured the stumble. I need to drive it more to be sure but I do not believe that the fuel pressure ever played a part in the stumble as I have never seen it drop.
I still have a little hunting for idle to work out.

 

Was this a TBI setup?

 

MPI on the Mustang.

 

That's it. I screwed with a Holley all day it's going in the trash ..

 

Don't trash it. I'll take it!

 

I drove the jeep about 100 miles yesterday. It still hunts for idle which is pretty annoying. At speed the jeep runs great. It is very crisp on the freeway, took it up to 80 mph without surging or hesitation. Fuel pressure remained a constant 12psi so I think I can positively say that the HEI cured the surging at speed. I am going to hook the brass tank selector valve back up and continue to monitor fuel pressure.
Turns out Steve's scanner is the old school Snap On brick type! Tonight I will get it hooked up and see what the ECM is reading.
Here is a short video of the jeep at idle. The hunting is not as obvious in the video as it is in person.

 

Just for kicks turn the ignition to run for 10 seconds ( with engine off) then turn the ignition off. Then start the engine.
I don’t know if you have tried it yet if you haven’t it’s the process to relearn the IAC worth a try.

 

If you can read the ecm data with the scanner and with the engine at operating temperature, at idle note the rpm, IAC position (count) and the TPS voltage. Also, if the IAC reset noted above by Mjragan doesn't help, you may need to re-calibrate the IAC which requires a few more steps.

 

The scan tool can’t relearn the IAC, it can control it but it won’t relearn it. This system is old school.
The scan tool data can be helpful, I would like to see the RPM signal in the data list, if the RPM signal is not stable enough the ECM could be trying to correct what it thinks is an unstable idle. Just a thought some times you have to do the key on engine off learn procedure a couple times before it learns.

 

Just throwing this out. Could the fuel octane have any thing to do with this

 

Here is 2 mins of running on the scanner with live data. First part of the video is running at idle... second half of the video is with the hand throttle set at 2000 rpm. The poor idle is much more obvious to the ear in real life.
To me the RPM jump seems a little extreme. I am going to swap to the proper polarity ignition coil this morning and try it again.

 

Watching the scanner, it appears the IAC is effecting the idle rpm. Looking at the scanner you will note the counts rise and fall as the idle surges. At idle you would expect to see the count in the middle teens whereas yours are varying and in the upper thirties and forties. Your TPS voltage is constant but it is a little high for the idling engine. It is 0.84 volts when you would expect to see it at about 0.59 volts.

I suggest you do the following to bring the IAC and TPS down into their expected range at idle. This info is from a pdf file I have regarding TBI.

1- Engine warmed up, key OFF, tranny in park or neutral.
2- Put a jumper wire from pin “A” to pin “B” on the ALDL connector (should be the black wire & white wire) A metal paper clip works good for this.
3- Turn key to ON, do not start engine, wait 10 seconds. This will extend the IAC pintle and close off the air passage in the body of the TBI. Remove the electrical connection to the IAC by pulling it straight out. Turn the key to OFF and remove the jumper from the ALDL connector.
4- Start engine, and let it settle into idle speed. You may need to give it a little throttle to get it running. Connect the scanner to the ALDL and check the engine RPM. You want the engine RPM to be at least 125 rpm less than what the “target idle speed” is set for in the chip. Use the throttle screw to obtain the “125 rpm less” idle speed. Example: Target idle speed in the chip is 700 RPM less -125 minimum idle speed = 575 RPM 5- Turn engine OFF. Connect the IAC connector.
6- Start engine and run for 5 seconds, turn engine OFF and wait at least 30 seconds. This will reset the IAC control.
7- Start engine, in park or neutral, let it idle. Idle speed should be close to the “target idle” set in the chip, if the IAC is being controlled by the ECM. Connect the scanner and check the IAC counts. The counts should be in the 10 to 15 count range, but can vary some, and will have a higher count at higher elevation, or for a fresh rebuilt engine. IAC counts are how the ECM knows where the position of the stepper motor is, in relation to fully closed or fully open. When the engine is shut off, the IAC will go fully closed and then open to a pre-determined amount of count steps to prepare the TBI for the next engine start-up.

Now that we have the “minimum idle speed” set, let’s take a look at the “throttle position sensor” voltage. The TPS voltage reading is how the ECM knows in what position the throttle blades are. With the scanner connected to the ALDL, and the throttle closed, see what the voltage reading is. You want it in the .58 to .59 volt range. If the TPS voltage is incorrect, it will be necessary to rotate the TPS sensor to get the correct voltage. Some of the TPS sensors have elongated mounting holes so they can be rotated. The sensors without the elongated holes can be modified by using a dremel tool and bit to elongate the holes, to help in setting the correct voltage. This setting is quite sensitive so proceed with caution when modifying the holes.

Edit: I should have added. As noted, TBS voltage is very sensitive. With key on and engine off, use your scanner as your volt meter. It will give you a very accurate voltage and exactly what the ecm is seeing.

 

I have done this a couple times but did not know the exact idle setting until I got the scanner. I will warm the engine and try the IAC calibration again. After that I will work on the TPS.
Thank you for your help.