# EFI Tuning/timing Help



## Atarchus (Aug 4, 2020)

I was hoping to get some assistance with my current build, motor is as follows:

400 block bored and stroked to 461ci
Edelbrock D-port aluminum heads, ported to 310cfm
Hydraulic roller cam: 230/236 @ .050 on 112lsa
Edelbrock Pro Flo 4 EFI

Currently running 36 total spark advance, all in at 3000rpm (which seems to run great)
Initial advance was set to 15 degrees, but the motor had poor starting and light throttle hesitation during normal driving. I worked my way up to 18 degrees and both starting and hesitation have improved greatly. I set it at 20 degrees initial timing and both the starting and hesitation issue seemed to be completely gone. My question is, how much initial timing is too much? 20 degrees seems like an awful lot, I just want to make sure I'm not pushing things too far. Any help/guidance would be greatly appreciated!


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## Lemans guy (Oct 14, 2014)

20 is not too much, I set most idle timing at 20 to 24 , but the key is that 10 degrees of this needs to come from vacumn advance. That way you could keep your 15 base and have 36 total....and add ten at idle from vac for 25 degrees idle timing. And you dial that down to 24 or 22 if you felt it idled better.

you have good you need to fix and get correct vac advance for it to run really good and idle cool, is it HEI dist or points type with separate coil?


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## Lemans guy (Oct 14, 2014)

Don’t push past 36 total timing, that is base and centrifugal together.....you can only add more with vac advance because it drops out when you throttle down so does not factor into total timing, but is still necessary...you have good numbers, fix the vac right


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## Atarchus (Aug 4, 2020)

Timing is controlled via the ECU on the Pro Flo 4, right now I have it at:

Initial timing - 18 degrees 
Advance start: 1200 rpm
Total spark timing: 36 degrees
Total spark rpm: 3000
Vacuum advance - 7 degrees

I'll bump the initial back up to 20 degrees because it runs better there.


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## BearGFR (Aug 25, 2008)

Atarchus said:


> Timing is controlled via the ECU on the Pro Flo 4, right now I have it at:
> 
> Initial timing - 18 degrees
> Advance start: 1200 rpm
> ...


As long as the engine is happy and isn't hard to start because it has so much initial that's it's trying to "kick back", then don't worry about having a lot of initial timing in it. 

Bear


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## Lemans guy (Oct 14, 2014)

20 is fine on initial not too much, bump your vac up to 10 degrees, ....it willl help that leaner burn at cruise and you should be good.


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## Atarchus (Aug 4, 2020)

Just wanted to update this if anyone finds it in a future search, these are my current timing settings on the Pro Flo 4 and it's running great so far:
Initial timing - 20 degrees
Advance start: 1200 rpm
Total spark timing: 36 degrees
Total spark rpm: 3000
Vacuum advance - 10 degrees
To get the cold starts dialed in, I got the engine nice and warm and after a drive I adjusted the idle fuel until it was within -5 of the LT Fuel trim. Then, I had to adjust the cold start enrichment values and actually pull fuel because it was too rich during cold start. I ended up at -10%, and then down to -5% and 0% on the last two degree ranges before fully warm. I'm currently at +20% cranking fuel, I'm still adjusting this to see if it cold starts better with more or less fuel but this should give anyone looking a good idea where I ended up.
Build:
461 Stroker
Edelbrock D port heads, ported to 310cfm
XE282HR-112 cam


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## Atarchus (Aug 4, 2020)

Just wanted to update this if anyone finds it in a future search, these are my current timing settings on the Pro Flo 4 and it's running great so far:

Initial timing - 20 degrees 
Advance start: 1200 rpm
Total spark timing: 36 degrees
Total spark rpm: 3000
Vacuum advance - 10 degrees

To get the cold starts dialed in, I got the engine nice and warm and after a drive I adjusted the idle fuel until it was within -5 of the LT Fuel trim. Then, I had to adjust the cold start enrichment values and actually pull fuel because it was too rich during cold start. I ended up at -10%, and then down to -5% and 0% on the last two degree ranges before fully warm. I'm currently at +20% cranking fuel, I'm still adjusting this to see if it cold starts better with more or less fuel but this should give anyone looking a good idea where I ended up.

Build:
461 Stroker
Edelbrock D port heads, ported to 310cfm
XE282HR-112 cam
Edelbrock Pro-Flo 4 EFI


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## Lemans guy (Oct 14, 2014)

You are looking great on that timing and AFR, should run real strong and cool right there! Good work


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## Atarchus (Aug 4, 2020)

Lemans guy said:


> You are looking great on that timing and AFR, should run real strong and cool right there! Good work


VERY cool! I also put in a cold case radiator and 180 degree thermostat. With current weather around 65 degrees it runs at about 170-175 while cruising and about 185 when in traffic. Hoping it's a good sign I won't have heat issues in the summer!


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## Lemans guy (Oct 14, 2014)

When your cooling system is all correct in top shape.....making the idle timing more advanced.......like you did to 20,...helps with engine cooling. It is not enough to overcome a bad cooling system, but just enough to aid a good cooling system.

in the 60’s car manufactures reduced idle timing to comply with government demanded for cleaner air. By reducing idle timing, the exhaust runs hotter and burns off noxious fumes. But making the exhaust hotter,..guess what,....makes your engine run hotter.

so stay cool!


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## GIgtoGuy (Jun 24, 2021)

I am currently looking at installing the set up and wondered how you liked it up to this point? Did you install an aftermarket tank where or did you stick with the original? What fuel pump are you using with your set up?


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## Atarchus (Aug 4, 2020)

GIgtoGuy said:


> I am currently looking at installing the set up and wondered how you liked it up to this point? Did you install an aftermarket tank where or did you stick with the original? What fuel pump are you using with your set up?


I just one of these EFI ready fuel tanks:


https://butlerperformance.com/i-25178192-1969-1970-pontiac-gto-and-lemans-fuel-injectiongas-tank-tan-tm34d-t.html?ref=category:1313613



Overall the system is great, I dialed back timing a bit to 34 degrees at 3500 rpm just to be safe. But it starts up and runs great with no need for further adjustments once it's dialed in.


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## GIgtoGuy (Jun 24, 2021)

I did see Butler has complete set ups including the tank. The tanks are on back order 10 to 12 weeks they say. I think I’m going to pull the trigger on the set up as my carburetor has been nothing but headaches since my 461 stroker was complete


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## Atarchus (Aug 4, 2020)

GIgtoGuy said:


> I did see Butler has complete set ups including the tank. The tanks are on back order 10 to 12 weeks they say. I think I’m going to pull the trigger on the set up as my carburetor has been nothing but headaches since my 461 stroker was complete


Yea, I'm a little too young for the carb era. Only thing I remember is my mom's 76 Buick had a carburetor when I was a kid and it never ran right and stalled regularly. EFI was a no brained for me lol.


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## GIgtoGuy (Jun 24, 2021)

I was curious what you went with for your throttle cable and bracket on that EFI setup. Also curious if your car had cruise control and what kind cable you would use for that? Thanks for your help


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## GTO44 (Apr 11, 2016)

GIgtoGuy said:


> I was curious what you went with for your throttle cable and bracket on that EFI setup. Also curious if your car had cruise control and what kind cable you would use for that? Thanks for your help


Dakota digital has a cruise control module. It has a small cable coming out of it that you connect to the throttle lever. You mount the box somewhere in close proximity. When activated the cable pulls the throttle to the current position and holds speed. You have to provide it a speed input which can be done with the included analog to digital cable converter. Or you can get the electronic signal version and use a gps module or VSS sensor from a modern transmission.

Cruise control for standard cable drive speedos:





Cruise Control for Cable Driven Speedometers


Dakota Digital manufactures digital instrumentation and accessories for the automotive, motorcycle and car audio enthusiast.



www.dakotadigital.com





Cruise control for digital speed input:





Cruise Control for Electronic Speedometers


Dakota Digital manufactures digital instrumentation and accessories for the automotive, motorcycle and car audio enthusiast.



www.dakotadigital.com


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## GIgtoGuy (Jun 24, 2021)

I have the same proflo4 on my 461. All is good except for is there such a thing as too much initial timing? I have the Edelbrock Proflow4 and I have it running good but I am unsure where exactly to set my initial timing as it seems to run the same at 12 than it does at 20? Benefit s of more or less initial?


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