[Diy_efi] escort sequential injection for tbi

[Mike Yates]

You said you built the I/M what's the finish on the ID of the runners
look like?

Would polishing the runners help this situation drastically?

That might be the easiest way, and you could gain some hp if you clean
it up im sure.

Mike


On Thu, 11 Jan 2007 07:42:14 +1100, you wrote:

>
>Jim I am guessing it goes lean because the sequential ecu does not compensate for the effects that you are getting by having a 'wet' manifold. As you get on the gas, the thickness of the fuel film on the walls of your manifold increases. The increase in mass of the fuel film means some fuel was 'stolen' from the inlet air/fuel flow during the throttle transient. I would imagine EEC IV can compensate for this...EEC IV must be used on tbi applications. Look for a manifold wetting coefficient or the like.
>
>> Hello to the DIY EFI'ers, I am new to this site.  I have been tinkering
>> with EFI for a couple of years and find the discussions interesting,
>> especially when I see someone solve a problem I had or one I haven't yet
>> discovered.  I started out transplanting an '87 Ford 5.0 into my '79
>> Ford pickup.  I then converted it to a mass air system from a '92
>> Mustang to eliminate some idle and hesitation problems that apparently
>> came from using different intake and exhaust systems with the
>> speed-density system.  The '92 mass air system adapts the mixture
>> automatically and runs great, even though it is on a truck engine.  In
>> fact, I was so pleased with the way it ran that I put a similar system
>> on my '71 MGB.  It turns out the system from a '92 Escort (I notice some
>> of you are from UK or Australia, I am talking about the American 1.9
>> liter variety) runs ok on an MGB 1.8 engine.  The MG is a 4 cylinder - 5
>> port engine, like the ones discussed on this forum a week or two ago.  I
>> originally built the manifold with two injectors at each of the two
>> intake ports, but the idle was rough and it had hesitation, so I built
>> another manifold with all 4 injectors in the center, sharing flow with
>> all 4 cylinders.  It was a sequential injection system in the Escort,
>> but it is now working as if it was throttle body system.  It still has a
>> hesitation during throttle transients, but runs great at constant
>> throttle.  I still have some theories on what might be causing this.
>> (have monitored TPS, ECT, EGO, etc, signals and can find no obvious
>> reason why it goes lean during transients)  I am hoping to find a setup
>> that works without changing the program in the ECU, but may have to
>> eventually get to that.  My question is:  has anyone reverse-engineered
>> the software in the Ford EEC-IV?  This seems to be a very capable and
>> robust ECU, and they are available for CHEAP at salvage yards around
>> here, so I am looking at how I could change the program it if necessary.
>> I think there is a real need for an affordable EFI conversion for these
>> old cars.  Jim from Ohio
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