Willys43

[Willys43]

Hi everyone, I'm a retired commercial carpenter with a new project. I have a 43 Willys jeep with a 62 Buick v-6 and I'm planning on putting TBI on it, and I'm sure gonna need you folks knowledge. Thanks in advance for your help

Craig

[dave w]

The Odd Fire Buick V6 is not an easy TBI conversion if you plan to use the computer for spark control. The Odd Fire distributor reference pluses to the TBI computer will cause problems.

I suggest consider upgrading to a TBI 4.3 V6 engine.

dave w

[1project2many]

I agree with the "odd fire" problem. Maybe a '78 to '86 RWD 231 will fit without headaches?

[dave w]

I agree with the "odd fire" problem. Maybe a '78 to '86 RWD 231 will fit without headaches?

That is an excellent option! See attached for a fuel injected even fire Buick V6 I did about 10 years ago. To save some $$$, I eliminated the "Turbo" from the EFI system. A little know fact ... the Buick V6 High Port intake is a mirror image design, which means a FWD Port Fuel Injected intake can be mounted in the forward direction on a RWD block.

Buick V6 engines are AWESOME, not the most BUDGET friendly engine to adapt fuel injection to.

It's very likely, a used good running TBI 4.3 V6 with a bellhousing adapter would be less money than adapting fuel injection to an even fire Buick V6? Finding a good running used even fire Buick V6 engines will be challenging vs. finding a good running used TBI 4.3 V6?

Is it possible to convert the Buick 225 to even fire, yes. Is it practical to convert the Buick 225 to even fire, likely not.

dave w

[Willys43]

Thanks for the info, I have read that adding a crank signal would eliminate the signal pulse issue. What about map sensor reading from the pulsing air stream caused by the irregular opening of the intake valves? I would prefer to use 78 Hei distributor with computer control spark. If I changed engines I would use a 3.8.
CraigC

[dave w]

I did a Google search;
http://forums.off-road.com/jeepster-...ct-update.html
&
http://forums.off-road.com/jeepster-...ion-works.html

The links I've posted appears to be a fuel only Odd Fire Buick V6 TBI conversion? You could retain the original "Points Distributor" with a fuel only TBI system.

I was thinking along the lines of having an ECM with full functionality, controlling fuel and electronic spark advance (ESC).

I'm thinking for a fuel only TBI conversion, the MAP sensor will be OK with the odd fire pulses. The 7747 is an extremely slow computer, by today's standards, with a fuel table that has a broad scale 400 RPM increments x 10 Kpa increments.

dave w

[Willys43]

Dave, I lied, The distributer is a '75 model, 78 would be even fire. Do you understand why the timing doesn't work properly? My distributor is electronic with vacuum and mechanical advance, I would prefer full computer control. The links you posted I had already found. To me that is even fire fueling on an odd-fire engine, which is probably OK. How do you fix the timing? Have you ever seen the interior of an electronic odd fire hei distributor? I put the same system on an a 6 cyl fj40, I couldn't get it to run right on a points distributer, but when I put an electronic distributer in it, it worked pretty well with Howell Engineering chip.
CraigC

[Willys43]

Dave,
I lied the distributer is a '75 model, 78 would be even fire. Do you understand why the timing doesn't work properly? My distributer is electronic HEI with mechanical and vacuum advance, but I would prefer computer control. I have read the links you posted. It seems to me he has an odd fire engine with even fire TBI fueling, which evidently works. How do you fix the timing? Have you ever seen the interior of an electronic odd fire distributor? I put the same system on a 6 cyl FJ-40 and it wouldn't run on breaker points, a chevy electronic distributor corrected the problem.
CraigC

[dave w]

Dave, I lied, The distributer is a '75 model, 78 would be even fire. Do you understand why the timing doesn't work properly? My distributor is electronic with vacuum and mechanical advance, I would prefer full computer control. The links you posted I had already found. To me that is even fire fueling on an odd-fire engine, which is probably OK. How do you fix the timing? Have you ever seen the interior of an electronic odd fire hei distributor? I put the same system on an a 6 cyl fj40, I couldn't get it to run right on a points distributer, but when I put an electronic distributer in it, it worked pretty well with Howell Engineering chip.
CraigC

The links I posted show even fire fuel only on an odd fire engine.

The HEI distributor is better than points. No need to discuss the points distributor any further.

The HEI pickup coil is different Buick V6 Even fire vs. Buick V6 Odd Fire. See attached pictures. The even fire HEI pickup coil is evenly spaced.

The extremely short version on the operation of the HEI pickup coil for a TBI fuel injection system is:
When the distributor is spinning, a sine wave Alternating Current (AC) signal is generated and sent to the ignition module. The ignition module converts the AC signal to a square wave that the ECM uses to determine RPM. The odd spacing in the in the Odd Fire pickup coil will be sending unevenly spaced AC signals the Ignition Module, thus creating unevenly spaced square wave signals the ECM used to determine RPM.

I can not think of a way to get full ECM control of both fuel and spark on the Buick Odd Fire engine.

dave w

[lionelhutz]

To expand on Dave's answer. To advance the timing from the base setting, the TBI systems calculate a delay time and fire the ignition after each pulse by the delay time.

In other words,
The computer has been measuring and calculating the time between each pulse that it is receiving.
It knows each pulse is 10* before TDC (or whatever value is programmed since this can be set in the bin).
It can then calculate how long to delay after receiving each pulse before firing so that the next cylinders spark is more than 10* ahead of it's pulse.
So, when say the pulse for cylinder 1 is received, the computer delays and then sends back a pulse that fires cylinder 2 at the correct time. Then, right after firing cylinder 2, the pulse representing cylinder 2 is received and it calculates a delay before sending back a pulse to fire cylinder 3, and so on.

The problem with all of the above is that the timing calculations are done assuming even firing. So, using it on odd firing means the timing would constantly be off. My best guess would be 1/2 the cylinders would be retarded and the other half advanced when compared to the programmed timing advance.

[1project2many]

Well.....

It is possible to control both spark and fuel on the odd fire V6 engine using existing OBD1 ecms and stock code. If you consider this engine to be dual three cylinder engines, each having its own combustion events separated by 240 degrees, then the job of delivering spark and fuel could be assigned to two independent systems, each having its own pickup coil, ignition module, and ecm. The challenge would be in bringing these two systems together at the engine. I don't see fuel delivery as an issue. With the 1-6-5-4-3-2 firing order a dual ecm configuration would group odd cylinders with one ecm and even with the other. This configuration would allow either three port injectors or one TBI injector per ecm per bank. Conveniently the stock intake is configured so each cylinder bank has its own plane and carb connection. Spark OTOH requires some thought. Something like the old Spaulding / Grant Flamethrower or Rotofaze dual coil distributors would be trick, but it is possible to use high voltage diodes to connect the secondary leads from two coils so they each can send spark through the distributor.

I am thinking that the introduction of one additional sensor for synchronization might allow custome code which could tolerate the differences in timing between cylinders. It is a challenge that I wish I had time to take on.

[Willys43]

Well is right, that one lost me. What if? If I put a crank trigger for a 12 cyl on it. It would send six sparks thru the odd fire cap, and six sparks between terminals in the cap. That way the computer would get even 12 pulses while only firing 6 cylinders?

[1project2many]

The problem is that the time between cylinder firing isn't even. The computer isn't set up to deal with it. The ecm will think the engine is speeding up then slowing down, over and over. Doubling the pulses still doesn't fix the 90 / 150 / 90 / 150 split. You can do fuel only which will make a big difference, but spark control will take some effort.

What I was saying was to install two computers and let each one handle three cylinders. You'd have to do some customizing to the distributor and you'd need some "special" spark plug wires but it would be do-able.

[Willys43]

1project 2many, I just finished a long scrip and when I tried to post it the forum said I didn't have permission and I needed to refresh the page. I ended up having to re login and wiped out my script. How do I refresh the page without wiping out what I have typed
Craig

[1project2many]

When you log in, check the box that says "keep me logged in." Also, sometimes at the bottom of the reply box you'll see a small button that says "Restore Saved Content." Click on that will bring back the last post you typed but didn't send.

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