MSD Atomic EFI: Tuning Tuning Tuning

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Dr. Marneaus
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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Mon Dec 12, 2016 11:39 am

Okay, so it seems a bit improved over the last tune, but still bein' weird.

It has generally only "hunted" one time during cold starts. comes up to around 1000 rpm, tries to settle down to like 750-800 and bogs, then comes back up and idles 100% normal.

However, yet again, when i hope in and try to drive, it struggles to hit 1800 RPM that first time. as soon as i can get it over 1800, it straightens out and flies right. super bizarre that it almost refuses to hit 1800 rpm, then all is well once i baby it there.

That did, indeed, happen before the HEI, but not every time. seems odd.

otherwise its cruising real well. I just cant get over the bogging down when i try to drive it initially.

I also havent noticed any of the hot start stumble either.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Cataldo
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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Cataldo » Thu Dec 15, 2016 6:19 am

What have the people from MSD said? It is very disheartening how much trouble you have had with this system
Jay

1975 Jeep Wagoneer: 350 SBC, TH400, Q/T, D44's 3.54:1's. Hell Creek 4" lift with BFG KO2 33x10.5s.

1988 Jeep Wrangler: 305 SBC, TBI, 700r4, NP231c with SYE, 9" w/ Detroit and 4.11:1, 5.25" of lift, 31's. Done up as a Jurassic Park Jeep (Her's)

1973 Chevy Camaro: Vortec 350, 200-4r, GM 8.5 3.23's. 12.4 @ 108mph.

1965 Ford Mustang: Aluminum Headed 347, c4, 3.00:1 gears, High 12's (Her's).



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Dr. Marneaus
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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Thu Dec 15, 2016 1:18 pm

Cataldo wrote:What have the people from MSD said? It is very disheartening how much trouble you have had with this system


I havent spoken to anybody at MSD. I didn't think I've had trouble just thought I was attempting to tune out some hiccups.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Thu Dec 15, 2016 2:05 pm

I created a thread on the atomic EFI forums. We'll see.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby babywag » Sun Dec 18, 2016 11:14 am

If the problem only exists on a cold engine?
Or, after a restart I would carefully examine the coolant/engine temp sensor.

Do the readings jive with engine temp?

For example a warm engine and a low sensor reading = engine running pig rich
Or, cold engine and high reading = engine running too lean
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Tue Dec 20, 2016 11:30 am

babywag wrote:If the problem only exists on a cold engine?
Or, after a restart I would carefully examine the coolant/engine temp sensor.

Do the readings jive with engine temp?

For example a warm engine and a low sensor reading = engine running pig rich
Or, cold engine and high reading = engine running too lean


I have not used a thermometer to test the coolant temp at the T stat housing or anything, however, the readings on the MSD display have been in line with everything that I have experienced in the past, when running a mechanical temp gauge. I suppose its temp range could be off in that it could be inaccurate at either end of the spectrum, but i've observed basically the exact same temps since installing.

i could get an IR thermometer and check though.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby babywag » Tue Dec 20, 2016 12:00 pm

I just mention it because we have all been assuming that everything is new/good/working properly.

This may not be the case?
A bad sensor will absolutely cause issues, you cannot tune out a problem. You can lessen them sometimes, but it'll still be there.

Since it seems like an initial start, drive problem. This suggests a problem with fuel?
Too much/too little fuel being delivered vs. what the engine needs.

For another example a bad o2 sensor or incorrect reading to the ecm.
Say the o2 sensor gives a false lean signal, and the computer adds fuel to compensate when the engine doesn't need it.
You get an engine that runs pig rich/stumbles/stalls.
Or the sensor reports the engine is overly rich, the computer pulls fuel, you get an engine that runs way too lean/no power/backfires.
On initial start the o2 sensor is NOT used, until the timer and temp. conditions are met then engine goes closed loop, and adjusts the fuel trims based on
sensor readings.

If your engine ran poorly more of the time or after initial start/drive I'd say look @ the o2 sensor.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Tue Dec 20, 2016 8:16 pm

babywag wrote:I just mention it because we have all been assuming that everything is new/good/working properly.

This may not be the case?
A bad sensor will absolutely cause issues, you cannot tune out a problem. You can lessen them sometimes, but it'll still be there.

Since it seems like an initial start, drive problem. This suggests a problem with fuel?
Too much/too little fuel being delivered vs. what the engine needs.

For another example a bad o2 sensor or incorrect reading to the ecm.
Say the o2 sensor gives a false lean signal, and the computer adds fuel to compensate when the engine doesn't need it.
You get an engine that runs pig rich/stumbles/stalls.
Or the sensor reports the engine is overly rich, the computer pulls fuel, you get an engine that runs way too lean/no power/backfires.
On initial start the o2 sensor is NOT used, until the timer and temp. conditions are met then engine goes closed loop, and adjusts the fuel trims based on
sensor readings.

If your engine ran poorly more of the time or after initial start/drive I'd say look @ the o2 sensor.



Wait the o2 sensor readings have zero to do with the engine until it's up to operating temp? 5$3' how does the system know how much fuel to provide?

The AFR readouts on the display are not influencing the tune in any way shape or form until it hits 165?
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby babywag » Tue Dec 20, 2016 9:37 pm

In a nutshell when first started the system is operating in what's called open loop.
Based mainly off the fuel map and sensor input(s) and some subroutines that dictate operation. When in open loop the oxygen sensor readings are not used.

Generally a FI system setup to use an oxygen sensor(s) has thresholds/conditions that need to be met before going to closed loop operation.
Temperature and time running parameters are met, then subroutines kick in allowing the computer to adjust fuel trims based on oxygen sensor readings.
Sensor reads rich, computer pulls fuel, etc.

A good tune and you can/should be able to drive truck normally. Even with the o2 sensor(s) disconnected or disabled.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby babywag » Tue Dec 20, 2016 9:51 pm

Your display probably has a "closed loop" readout? on/off or closed loop/open loop?
This would tell you...
When do your " issues" happen? when system is NOT closed loop or IS closed loop?
Or doesn't it matter?
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Tatsadasayago » Wed Dec 21, 2016 12:48 am

I realize I totally forgot I mentioned going up to Reno this weekend. One of the things I was going to do is disconnect the O2 and coolant temp sensors and see how his jeep behaved staying in Open Loop after reaching operating temp. I have a sneaking suspicion that the default fuel mapping is not working with his engine setup. I know jack about the MSD Atomic, so I will assume altering/editing the mapping is not an option. I was planning on performing a cyl pressure test as well as going over all the vacuum-related items in case he's got a mechanical issue that the EFI system cannot see during open loop...
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Dr. Marneaus
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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Tue Dec 27, 2016 10:43 am

babywag wrote:Your display probably has a "closed loop" readout? on/off or closed loop/open loop?
This would tell you...
When do your " issues" happen? when system is NOT closed loop or IS closed loop?
Or doesn't it matter?


Thanks for the explanation about this post. I understoof partially about the closed/open loop, but did not understand that the o2 sensor has zero influence on the tune until everything is warmed up.

My system does, indeed, indicate whether its open or closed.


It seems to be present in both situations. If i allow the truck to warm up to 165, it still seems to happen, vs. if I hop right in at 45* ECT and drive.

Hunting only happens on the first cold start. Yesterday I went outside, It was like 18*, ECT was 25* according to the EFI. It fired up quickly, instantly bogged to like 450rpm, bounced up to 700, then down to 400, 300, 200 and stalled. All within a few seconds (maybe 15 seconds from start to stall). Bumped the key again and it fired up instantly, and idled like a champ. I allowed it to hit 165 before taking off, and I actually made the engine hit about 1800RPM before going into gear. Within 100 yards of driving, it stumbled. I mashed the gas and it powered through it withou8t me getting off the pedal, then drove great for the rest of the day.

I've noticed it feels responsive and strong the way its tuned currently. I have no complaints in that department. Just still doing the silly start up issues.

Another thing. I only pulled in 8.5mpg this tank. EEK. It did include several "warm ups" without driving, letting it warm up a few times before driving, and i had it idling quite a bit last weekend while taking some pictures in the desert. Aside from that, it was city driven a lot too. I'm not super worried about that but damn thats worse than I EVER got with a carb.

I pulled a few plugs to see how things seem, one from each bank, and they were both off-white but not bright white, perhaps a bit lean if anything. No evidence of being too rich or anything.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby babywag » Tue Dec 27, 2016 6:10 pm

Bump fuel pressure up 5psi, and see what next cold start does.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Wed Jan 04, 2017 2:48 pm

babywag wrote:Bump fuel pressure up 5psi, and see what next cold start does.


will do! Havent fired it up in a while, since last posting.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Wed Jan 11, 2017 11:55 am

Its been tool cold to dick around with anything.

I drove it the other day, and also started up and moved it several times while working on a project in the garage. Its started fine aside from some relatively minor hunting.

It still did the initial drive stumble, but other than that it drives fine once everything is up and running.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Dr. Marneaus
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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Wed Jan 25, 2017 2:08 pm

Drove it the other day and it started up perfect in freezing weather. put 150 trouble free miles on it.

I despise the fact that it starts fine sometimes and gives me trouble others.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Dr. Marneaus
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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Tue Jul 11, 2017 9:40 am

Well, its running strong lately, still does the hiccup on start thing though. I put maybe 1200 miles on it over the past month or two.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Dr. Marneaus
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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Dr. Marneaus » Wed Nov 22, 2017 10:32 am

FYI this thing still doesnt work right and Ive adjusted nearly every setting.

Seems like the stumble is stronger and longer now.

Oh well.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.

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Re: MSD Atomic EFI: Tuning Tuning Tuning

Postby Stuka » Wed Nov 22, 2017 3:34 pm

Is it only on cold start, then goes away?
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