Mk3 Interceptor: This is my 440 EFI conversion log.

[Philip Lochner]

Thanks for you interest, support and willingness to help Bruce. This is a very lonely business - more so when you are at the @rse end of Africa....

Have you adjusted your transient fueling at all?

With "transient" you mean for those instances where the throttle moves? In my case I do not use MAP for transient fuelling at all- it is disabled. MS allows you to do that but I use only TPSdot ie when movement in TPS position is detected.

Your intake and TB should not have such a profound effect that you cannot smooth out your fueling table. It is possible that you need to add some dMap (fuel added/subtracted due to the rate of change of the map signal) as the outer blades open up, adding air around/reducing vacuum at mid throttle.

I would not have thought so, but using a modified carbed intake, I'm seeing ghosts everywhere.... This fuel map is the fuel required under stable conditions, ie there should be zero throttle movement but of course the MAP (manifold pressure) signal can become quite lively.

Can the MS2 run log files? Looking at the actual AF as well as the TPS RPM MAP etc will help determine whats up.

Yep, in fact the PC user interface (Tunerstudio) uses the datalog data in real time to tune the fuel map for you. All you have to do is drive the car. In this instance though, I have found that the software gets all confused in that area of the bulge and I had to tune that area manually. But it can also save the datalog data to a file on the PC for later study using "Megalogviewer"

I wouldn't do any mechanical modifications yet (spacer, plenum, etc) as IMO most any manifold (even a chunk of pipe) can be made to work as an intake manifold with the right tuning.

I hear you. The TQ carb has a 3/8" heat isolator. I might just pop that under the TB as a "spacer" to see if I can see anything change. The guys in the video used a 1" but that will not be an option for me as then the air cleaner would most certainly interfere with the bonnet (hood).

I would also have thought that with mapped EFI, one should be able to tune to perfection, and this map does deliver the AFRs that I want, but that does not make it right necessarily. If there are REALLY air flow issues (and I'm still not sure if there are) those must surely be addressed first before accepting the fuel map as the final deal.

[Philip Lochner]

Fitted another idle valve today. Bosch # 0280140526. All I know about it is that it comes off a BMW E36 series.

Still need to plumb in clean air for it but decided that I also want to feed the PCV system with clean air from the same supply point while I'm at it.

Whilst I have full control of idle air now, I suspect the physical orifice that feeds idle air into the plenums are too small for this engine. Its a bit early to state thus categorically though.

My regular pc took a hit from lightning last night. Having trouble linking pics from dropbox.

[Philip Lochner]

Fitted another idle valve today. Bosch # 0280140526. All I know about it is that it comes off a BMW E36 series.

Still need to plumb in clean air for it but decided that I also want to feed the PCV system with clean air from the same supply point while I'm at it.

Whilst I have full control of idle air now, I suspect the physical orifice that feeds idle air into the plenums are too small for this engine. Its a bit early to state thus categorically though.

Here is the now flange I made for the new valve. The valve outlet port just slides into the round receptacle in the new flange and seals with O-rings. ( I did not do the welding )





This is the original bracket holding the idle valve via a rubber girdle. I should have taken pics of the modified one as well....



Idle valve mounted. 3 O-rings seal the valve outlet to the new valve feed flange I made.

[Steve Payne]

Having a small orifice should not matter if you set the throttle blades correctly.

Have enough air going past the throttle blades to go give you and idle of say 550rpm and use the IAC to supplement this to give you the correct idle.

This is how a lot of systems work and it allows you to still have an idle even if the IAC has a problem.

Steve

[Philip Lochner]

Thanks Steve, that is exactly how my LR Discovery 1 has to be set. What I have done on this car is to close the idle valve completely and then set idle rpm too 800rpm by adjusting the throttle stop. This means that its ONLY the additional air that is needed for cold running that needs to go through the idle valve route. Even so, I still dont get an idle rpm high enough when its cold.

I'll try again today, as one only gets 1 chance per day.

[Steve Payne]

I still dont get an idle rpm high enough when its cold.

Mabe you have to much fuel? When cold these engines only need about 11.5 to 12 to 1 to run and that is only for the first 30 seconds.

Try adding more advance when its cold if you can do that?

I run an additional 8 degrees for a cold engine and taper that off as it warms up.

Steve

[Philip Lochner]

Yep, it could be that im squirting too much fuel during cold cranking. If so, it takes too long to recover anyway. Ill have another go later this morning.

I could see with the carb already that it does not like being too rich. 11Afr is just about as rich as she will tolerate.

[Joerg]

I?m happy that I could avoid the installation of an idle valve
Keeps the enginebay clean.




Regards

Joerg

On FAST XFI 2

[Philip Lochner]

On FAST XFI 2

That is a seriously "alternative" implementation Joerg!!! Is that a continuous injection system?

[Philip Lochner]

OK, Its official
1) the port for the idle valve in the Edelbrock throttle body is too small for this 440 engine. On a cold start I have to supply additional air using the throttle. Plan A is to see if the hole can be drilled larger. Plan B will be to feed idle air directly into the plenums somehow.
2) my new fuel pump can not supply the volume required (which I suspected even as I bought it) - so monday will see me pump hunting again.

[Philip Lochner]

OK, Its official
1) the port for the idle valve in the Edelbrock throttle body is too small for this 440 engine. On a cold start I have to supply additional air using the throttle. Plan A is to see if the hole can be drilled larger. Plan B will be to feed idle air directly into the plenums somehow.

Having removed the TB with the intent of drilling the idle air ports larger, look what I found! The manifold essensially blocks the ports except for the small gap being left by the gasket between the TB and the manifold. The dark patch between the arrows shows where the idle valve port air hit the manifold:


Here you might also be able to see how the two idle air ports align with the two Y-shaped bosses seperating the two plenums.


Not having access to a milling machine at 5pm on an end of month Friday, I decided to do the necessary mods myself using "the means available to me". This would constitute the most vulgar of p0rn so I'm not posting pics of that. Suffice it to say that now both idle air ports can feed air unrestricted into the manifolds.

With the engine at operating temp and idle valve fully closed, she idles happily at 850rpm with air being supplied via the PCV valve and the fractionally open butterflies. If I now open the idle valve fully, idle speed goes up to 1700rpm. This is good stuff as now there is likely to be sufficient air for the engine when cold via the idle valve. This we will only know on Monday as I have no time to play over the weekend.

It seems I have to withdraw any and all previous statements regarding the idle valve fitted to the Edelbrock 38783 throttle body and the idle ports as it comes from the factory. If Edelbrock's support via the forum was as it should be, they could have responded (long ago) as follows:
"The Edelbrock 7193 intake manifold (being intended for carburettor) is not envisaged to be used with the 38783 TB. The two ports on the TB that is meant to supply idle air to the engine will be blocked except for the small gap being left by the gasket between the TB and the manifold. You could of course machine the manifold to allow air from the idle air ports on the TB into this manifold"

[Joerg]

No- this are only my vacuum pipes for my MAP sensor.
The Injectors are on the outside.
It is a full sequential injection and ignition but I want the "Old School" look.

Joerg

[Steve Prince]

OK, Its official
1) the port for the idle valve in the Edelbrock throttle body is too small for this 440 engine. On a cold start I have to supply additional air using the throttle. Plan A is to see if the hole can be drilled larger. Plan B will be to feed idle air directly into the plenums somehow.

Having removed the TB with the intent of drilling the idle air ports larger, look what I found! The manifold essensially blocks the ports except for the small gap being left by the gasket between the TB and the manifold. The dark patch between the arrows shows where the idle valve port air hit the manifold:


Here you might also be able to see how the two idle air ports align with the two Y-shaped bosses seperating the two plenums.


Not having access to a milling machine at 5pm on an end of month Friday, I decided to do the necessary mods myself using "the means available to me". This would constitute the most vulgar of p0rn so I'm not posting pics of that. Suffice it to say that now both idle air ports can feed air unrestricted into the manifolds.

With the engine at operating temp and idle valve fully closed, she idles happily at 850rpm with air being supplied via the PCV valve and the fractionally open butterflies. If I now open the idle valve fully, idle speed goes up to 1700rpm. This is good stuff as now there is likely to be sufficient air for the engine when cold via the idle valve. This we will only know on Monday as I have no time to play over the weekend.

It seems I have to withdraw any and all previous statements regarding the idle valve fitted to the Edelbrock 38783 throttle body and the idle ports as it comes from the factory. If Edelbrock's support via the forum was as it should be, they could have responded (long ago) as follows:
"The Edelbrock 7193 intake manifold (being intended for carburettor) is not envisaged to be used with the 38783 TB. The two ports on the TB that is meant to supply idle air to the engine will be blocked except for the small gap being left by the gasket between the TB and the manifold. You could of course machine the manifold to allow air from the idle air ports on the TB into this manifold"

How much did you have machined, if any, off of the top of "carb" mounting pad?

Older 7193's had a much deeper cut out between planes but your photo suggests NO top machining and a very shallow cut.

[bkbridges]

Philip,
A 7/16" Dia hole, unblocked , will support a 572cuin motor at idle. Glad to hear you found the problem! Im not sure how well your motor will tune without running it in speed density mode. Why the decision to go alpha N? Even the most radical builds (like Joerg's ) use a MAP for precise volumetric calculations. Map port placement/design can be a science unto itself on some intakes! I guess your transient fueling is dTPS only. That's kind of tough as it wont pull fuel at decel. Have some one drive behind you as you go full deceleration in a dropped gear. That made for a good flame thrower show on my car before I adjusted the decel fueling. Im not very familiar with the self tuning algorithms in the MS software. The FAST can be kind of clunky and does require some manual pruning/initial targeting adjustment before it will get the job done quickly. Foot on the throttle to start up usually means too much fuel in the starting enrichment table for your ambient and inlet temp. I need to download the tuner studio and check out its capabilities. The price sure is right. We are going to "first" fire my friends twin turbo 68 496cuin Dart this weekend if all goes well. Its got an older BigStuff 3 and runs a 3 bar MAP... should be interesting. I wonder if that would all squeeze into an Interceptor...
BKB

[Philip Lochner]

How much did you have machined, if any, off of the top of "carb" mounting pad?

Basically I did not machine the top of the carb mounting pad (at all), I just drilled holes from the TB idle ports positions into the manifolds. It looks horrible, so when I do pull the engine to do the AC system, I will have this machined properly.