Installing a XFI Sportsman Throttle Body EFI System in a 1965 Buick.

[elagache]

Dear mid-60s Buick owner with an eye to high-tech,

On Monday I went back to my routine of checking the status of the FAST XFI Sportsman electronic fuel injection system in my trusty wagon.  Just to size up the situation I took a video and logged a cold start.  I could see immediately that the engine wasn't idling as well as remember it used to when starting from cold.  I have the videos to prove that.  Here is the previous cold start video I took on September 2, 2016:



This video is being hosted on SmugMug but should work like any other video service.  Here is the video I took this past Monday:



So the 64-dollar question was why?  Here is the log I took of the start on September 2, 2016:



It is a bit difficult to see, but what I found is that this engine doesn't like to have much cold start enrichment.  Within 2 minutes, the actual air-fuel ratio was very close to the 13.81:1 ratio that was found the engine ran best when hot.  It had taken me a while to ascertain this, but I was clearly satisfied I made no changes after September 2nd.  Here is the log of the Monday cold start:



As you can see, the engine is now running substantially rich.  The instability is what I had observed in the past and clearly the engine isn't doing as well as possible.  Now here is the kicker - none of the parameters had been changed!  The only possible explanation is that the work of Mike Tomaszewski and his TA-Performance team reduced the mechanical resistance of the engine such that it takes less fuel to get the engine rotating when cold.

I thought this engine was running a lot better, but to me at least now there is objective proof!  Hat's off to Mike Tomaszewski and his guys!

Have a great weekend everybody!

Cheers, Edouard 

[Buicknut65]

AWEEESOOOMMMMEEEEEE !!!!!!!!!

[WkillGS]

......
The only possible explanation is that the work of Mike Tomaszewski and his TA-Performance team reduced the mechanical resistance of the engine such that it takes less fuel to get the engine rotating when cold.
.....

I don't think that's it. I suppose less drag could make it spin faster via the starter. Did they switch to low tension piston rings?
I do see the fuel pressure is now 48.2 vs the old 40.8 psi. That would shoot more fuel through the injectors and richen it up, making for a quicker start. Cold engines like a richer mixture, which is the purpose of a choke on a carbureted car.

Significant difference in battery voltage too....14.6 vs 11.9v, that's gotta help! That might explain the higher fuel pressure and it would also help the starter spin the engine faster.

Great to hear it's , I mean, SHE is doing well! Did you get it out on the highway yet?

[GreatScat1965]

Just curious, what is the can profile look like in this engine? All this EFI stuff is very intriguing.



Jerry

[elagache]

Dear Walt, Jerry, and mid-60s Buick owners who are curious about high-tech,

Thanks guys! 

I don't think that's it. I suppose less drag could make it spin faster via the starter. Did they switch to low tension piston rings?

It does appear that starting has less resistance.  Biquette doesn't get jerked around as much when starting now as before.  However, this isn't just at starting.  The air-fuel mixture is too rich for 4 minutes.  The engine is getting more fuel than it can use all that time, where as in September 2016 it was burning all that fuel.  I'm not sure how to explain it, but I double-checked and the cold startup parameters haven't changed.  In particular there is a table that provides extra fuel while the coolant temperature ramps up.  That's the table I found had values that were too high and I lowered to improve the cold start idle.  Once more it appears that I need to reduce these values still further to insure a smooth idle as the engine is warming up.

I do see the fuel pressure is now 48.2 vs the old 40.8 psi. That would shoot more fuel through the injectors and richen it up, making for a quicker start. Cold engines like a richer mixture, which is the purpose of a choke on a carbureted car.

Significant difference in battery voltage too....14.6 vs 11.9v, that's gotta help! That might explain the higher fuel pressure and it would also help the starter spin the engine faster.

Those are instantaneous values that are where the cursor is located and will vary significantly but for extremely brief periods.  So I don't think those are issues.

Great to hear it's , I mean, SHE is doing well! Did you get it out on the highway yet?

I haven't had a chance yet, but I'm trying not to drive her too much until the tires get replaced.  They are the 8 year old tires that the car sat on while the engine was away.  I really need to get on with the rear end change and switch to the new tires.

Just curious, what is the can profile look like in this engine? All this EFI stuff is very intriguing.

I could dig up the cam specs if you like but it is a variation on the Buick Stage-1 cam.  It is relatively mild, but has more bite than the passenger car cams that Buick would have used in the day.  The electronic fuel injection definitely helps with smoothing the idle, but that's where getting the parameters set properly is really important.  Gasoline engines really can run under a surprisingly wide set of conditions, but you won't get the best performance that way.  If you can actually set the parameters carefully, you really can get the engine to run more smoothly than either with a carburetor or even a self-tuning EFI system.  It is a matter of systematically adjusting the parameters and carefully observing how the engine responds to the changes.

Thanks again gang!

Cheers, Edouard 

[elagache]

Dear mid-60s Buick owners who are curious about high-tech,

Before heading out to fetch the groceries last Friday, I documented Biquette's cold start after modifying the warm-up fuel enrichment table to make the cold start less rich.  The results were truly puzzling.  To put things back into context, here is the video of the cold start I made on September 2, 2016.



Here is the video I took on Monday, June 26, 2018:



Finally, here is the video taken on Friday, July 6, 2018:



My reasons for relisting the previous two videos is to my disappointment that remains the ranking from smoothest idle to worst.  Perhaps to help (or I fear confuse) here are the parameters that are in that warm-up fuel enrichment table at various stages of tuning the engine:

Temperature	4/26/16	9/2/16	7/6/18
0? F	39.8	68.3	54.0
17? F	39.1	67.1	53.1
34? F	36.7	63.0	49.8
51? F	32.0	54.9	43.5
68? F	27.3	44.3	35.8
85? F	20.3	30.9	25.6
102? F	12.5	16.9	14.7
119? F	7.0	9.4	8.2
136? F	0.0	3.1	1.6
153? F	0.0	0.0	0.0
170? F	0.0	0.0	0.0

The first row after the coolant temperature values are the settings as Rich Nedbal had left them after he came by to tune the engine on April 26, 2016.  As you can see, I had to enrich the warm up settings quite a bit by September.  As I noted in the previous posting, what was almost spot on for the target air fuel mixture back then, is now significantly rich almost 2 years later.  Here is the log from the cold start of July 6:



If you compare it to the log of June 26, it isn't very different.  Even if the enrichment settings has been significantly reduced, the actual air fuel mixtures are very similar.  When I view the last two videos, I'm tempted to go back to providing more fuel during the warm up since the engine was idling significantly better on June 26 than on July 6.  However, when I compare all 3 videos, there is absolutely no doubt that the cold start of September 2, 2016 has the smoothest idle by far.

I arrived at the fuel enrichment values for my test of July 6 by taking the average between Rich's values and the values of September 2, 2016.  Since I don't understand too clearly what is going on, I think I should once nudge the values further down by the same procedure.  I need to determine whether or not the engine truly does idle best when the air fuel mixture is close to the final target after warm-up.  Looks to me like I'll have to continue some trial and error to find out!

Cheers, Edouard