Danny Cabral
Member
Posts: 3148
Loc: Ellington, CT
Reg: 11-03-04
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06-15-12 12:32 PM - Post#2237475
In response to Danny Cabral
If it's a momentary high idle, immediately after starting, decrease the IAC Parked Position.
If it remains high, but gradually slows down as coolant temperature increases, adjust the IAC Desired Idle.
Also, are the throttle blades properly set (idle speed screw on throttle body) to achieve an IAC Position of 10-15 counts (Data Monitor on Fuel Map) when the engine is fully warmed up?
Don't confuse the IAC Position (Data Monitor) and the IAC Parked Position (starting)...they're not the same thing.
May God's Grace Bless You
'78 BRONCO: 508" stroker, TFS heads, Dominator MPFI & DIS, A/C, Lentech Strip Terminator AOD, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim-over steering, 4" lift, 35" tires |
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-15-12 02:44 PM - Post#2237524
In response to Danny Cabral
It's getting better...I checked the timing for the first time and it looks off. I recall reading a post you did on setting the base timing. Can you give me that link?
Edited by 68wfo on 06-15-12 02:44 PM. Reason for edit: No reason given.
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Danny Cabral
Member
Posts: 3148
Loc: Ellington, CT
Reg: 11-03-04
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06-15-12 03:11 PM - Post#2237537
In response to 68wfo
It's getting better...I checked the timing for the first time and it looks off. I recall reading a post you did on setting the base timing. Can you give me that link?
Ensure the engine timing (timing light) is synchronized with the C950 ECU:
www.chevytalk.org/fusionbb/showpost.php?post/15646...
I am concerned as to why the settings I have look so far off. The guy I bought the car from said the shop that installed the system "knew" what they were doing. But when I look at the settings they made I have to wonder if they had any clue.
This doesn't surprise me at all. I've said it many times before...it's those so-called experts/professionals that I have the most trouble with. This is yet another example! I've been tuning EFI for about 12 years now, and I've never seen a performance shop get it right. I'm sure they exist...but not in my area.
May God's Grace Bless You
'78 BRONCO: 508" stroker, TFS heads, Dominator MPFI & DIS, A/C, Lentech Strip Terminator AOD, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim-over steering, 4" lift, 35" tires |
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-15-12 03:30 PM - Post#2237546
In response to Danny Cabral
I did as your write up says. In the spark map I set all the timing cells to 20 and checked the timing with a light. It showed nearly 40 degress with the light. I rotated the distributor to 20 degrees but it kept stalling so I increased the idle screw and was able to lock down the distributor. I adjusted the throttle blades so I could get 10 to 20 on the AIC reading. Seems to idle better. Before I take it for a drive is this the proper procedure?
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Danny Cabral
Member
Posts: 3148
Loc: Ellington, CT
Reg: 11-03-04
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06-15-12 03:58 PM - Post#2237552
In response to 68wfo
You'll know everything is right when you temporarily enter 20° (I prefer 30°) in the entire Spark Map, and:
1) The engine timing & C950 timing is synchronized.
2) Rev the engine and the ignition timing doesn't advance or retard.
Summary: The initial (idle) timing is synchronized by turning the distributor & locking it down. The timing at higher RPM (revving engine) is synchronized by adjusting the Ignition Propagation Delay in the EFI software. The first synchronization is physical, and the second synchronization is electronic. When finished, the timing as viewed on the laptop, should match what you see with the timing light, at all RPMs.
FYI: Just like a carbureted application, if your distributor ends up facing the "wrong" direction (aesthetics), you can remove the distributor assembly from the engine and reinstall it in the position you like without turning the inner shaft. You can remove the distributor cap and tape the rotor to the distributor body for maintaining alignment.
May God's Grace Bless You
'78 BRONCO: 508" stroker, TFS heads, Dominator MPFI & DIS, A/C, Lentech Strip Terminator AOD, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim-over steering, 4" lift, 35" tires |
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-15-12 04:57 PM - Post#2237576
In response to Danny Cabral
ok...I did as you suggested. I created a spark map of with 30 in all the cells. I started the motor and checked timing with the light. The timing mark showed 30 at idle but when I rev'ed the motor it retarded to about 28 degrees. I changed the propogation setting to 300 and the timing stayed at 30. Does this sound about right as far as how everything is going?
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zwede
Senior Member
Posts: 1501
Reg: 01-10-03
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06-15-12 07:11 PM - Post#2237627
In response to 68wfo
Yep, you're doing good!
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Danny Cabral
Member
Posts: 3148
Loc: Ellington, CT
Reg: 11-03-04
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06-15-12 11:49 PM - Post#2237707
In response to zwede
Yep, you're doing good!
Yes he is. He already has the EFI tuned better than that performance shop!
May God's Grace Bless You
'78 BRONCO: 508" stroker, TFS heads, Dominator MPFI & DIS, A/C, Lentech Strip Terminator AOD, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim-over steering, 4" lift, 35" tires |
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-16-12 07:18 AM - Post#2237773
In response to Danny Cabral
Thank you Danny and Zwede for all the help and words of encouragement. I hope to have time today to give her a test drive. Would either of you happen to have an updated AF ratio chart I might use? The one I have been using is the original and who knows if it is correct....thanks
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Danny Cabral
Member
Posts: 3148
Loc: Ellington, CT
Reg: 11-03-04
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06-16-12 08:01 AM - Post#2237788
In response to 68wfo
Would either of you happen to have an updated AF ratio chart I might use?
Here's a good example:
http://www.chevytalk.org/fusionbb/showpost.php?pos...
Read pages 4-10 of this Edelbrock EFI tuning manual, it's very good:
http://www.edelbrock.com/automotive_new/misc/t ech_...
May God's Grace Bless You
'78 BRONCO: 508" stroker, TFS heads, Dominator MPFI & DIS, A/C, Lentech Strip Terminator AOD, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim-over steering, 4" lift, 35" tires |
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-16-12 08:43 AM - Post#2237801
In response to Danny Cabral
Thanks Danny...do you have a fuel map that cooresponds to this AF ratio map? My thought is if I change my AF ratio map the fuel map cells I have been working on will need revising.
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Danny Cabral
Member
Posts: 3148
Loc: Ellington, CT
Reg: 11-03-04
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06-16-12 10:08 AM - Post#2237821
In response to 68wfo
Thanks Danny...do you have a fuel map that corresponds to this AF ratio map?
I do, but I was still TBI when I was using the C950, so it won't work for you.
I converted to MPFI & DIS shortly after upgrading to the Holley Dominator EFI:
http://www.network54.com/Forum/85220/thread/12 7767...
My thought is if I change my AF ratio map the fuel map cells I have been working on will need revising.
Yes, that's I previously stated to ensure you like your Target Air/Fuel Ratio Map before tuning.
Keep in mind, that Target Air/Fuel Ratio Map may need to be adjusted for your camshaft requirements (idle and highway cruising MAP & RPM).
May God's Grace Bless You
'78 BRONCO: 508" stroker, TFS heads, Dominator MPFI & DIS, A/C, Lentech Strip Terminator AOD, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim-over steering, 4" lift, 35" tires |
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-18-12 07:13 AM - Post#2238627
In response to Danny Cabral
My cam is a custom grind but I do know the cam specs. How do you match the AF ratios to the needs of the motor?
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zwede
Senior Member
Posts: 1501
Reg: 01-10-03
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06-18-12 07:38 AM - Post#2238645
In response to 68wfo
It's in the Edelbrock link Danny keeps telling you to read. 
Basically, a longer duration camshaft requires a richer mixture at low rpm as well as more timing advance.
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-18-12 07:53 AM - Post#2238651
In response to zwede
ok...I'll read it again...thanks
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-18-12 02:25 PM - Post#2238823
In response to 68wfo
Danny...Zwede...I took the car out for a test. It ran like cr@p. I did a datalog and save hoping you wouldn't mind taking a look. I exported the file as a BMP but it only shows the graph without any data. Can you tell me how to save the graph with the data info below?
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zwede
Senior Member
Posts: 1501
Reg: 01-10-03
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06-18-12 02:40 PM - Post#2238829
In response to 68wfo
I know Danny had good luck running very lean AFR targets, but my 454 never liked it. I idle at 13:1. Low rpm cruise 13.2:1 going to 13.5:1 @2000 rpm.
Remember: Rich wastes a bit of fuel but runs fine. Lean runs like crap. Better to be a little rich.
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-18-12 03:00 PM - Post#2238837
In response to zwede
I understand...I have built cars, raced cars and know a little about tuning (with a carb). This is my first venture into FI. Here is the pic of the datalog I just did. The top blue line is RPM at about 5,500. In reality I was around 1,500 with the motor jumping, curgling, spitting etc...I don't know how to save a picture with the data below it. I am thinking I am experiencing a bad ignition module or electo-magnetic interference...what do you think?
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zwede
Senior Member
Posts: 1501
Reg: 01-10-03
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06-18-12 04:14 PM - Post#2238864
In response to 68wfo
Hmmm... I've never seen anything like that. My guess would be more towards interference. I've had ignition modules go out and the engine just dies.
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-18-12 04:37 PM - Post#2238871
In response to zwede
I agree....it started prior to working on all the new setups. I loaded a previous file and still the same thing. I have not moved any wires around so I don't know where to start. Is it possible the ECU is needing a reset or something?
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Danny Cabral
Member
Posts: 3148
Loc: Ellington, CT
Reg: 11-03-04
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06-18-12 04:50 PM - Post#2238875
In response to 68wfo
Click on my user name for my email address, and send me a copy of your C950 file & datalog.
May God's Grace Bless You
'78 BRONCO: 508" stroker, TFS heads, Dominator MPFI & DIS, A/C, Lentech Strip Terminator AOD, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim-over steering, 4" lift, 35" tires |
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-18-12 05:16 PM - Post#2238888
In response to Danny Cabral
Doing now...thank you...
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-19-12 02:03 PM - Post#2239183
In response to 68wfo
What fuel pressure should I be running for Multi-port? It has always been set around 36 psi
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Danny Cabral
Member
Posts: 3148
Loc: Ellington, CT
Reg: 11-03-04
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06-19-12 02:34 PM - Post#2239190
In response to 68wfo
What fuel pressure should I be running for Multi-port? It has always been set around 36 psi
Your 42 lb/hr injectors should be set to the typical 43.5 psi fuel pressure (vacuum hose disconnected).
With 600 HP, I don't know why it's at 36 psi. You must retune if making a big change in fuel pressure.
FYI: If replacing the distributor's ignition module, purchase a genuine GM ignition module.
May God's Grace Bless You
'78 BRONCO: 508" stroker, TFS heads, Dominator MPFI & DIS, A/C, Lentech Strip Terminator AOD, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim-over steering, 4" lift, 35" tires |
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zwede
Senior Member
Posts: 1501
Reg: 01-10-03
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06-19-12 02:45 PM - Post#2239193
In response to Danny Cabral
36 is fine if it's at idle. The regulator is vacuum referenced so it will lower the pressure when there's vacuum.
Engine off, ignition on you should see 43 PSI.
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68wfo
Forum Newbie
Posts: 30
Reg: 11-03-11
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06-19-12 06:51 PM - Post#2239276
In response to zwede
Previous owner had it at 36. I will reset to 43.5...thanks.
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