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EFI tuning question by edfiero
Started on: 06-05-2015 04:44 PM
Replies: 8 (159 views)
Last post by: f85gtron on 06-08-2015 09:50 PM
edfiero
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Report this Post06-05-2015 04:44 PM Click Here to See the Profile for edfieroClick Here to Email edfieroSend a Private Message to edfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Question for those guys that have done some tuning before.
I took the SD4 out for a trip around the block today. It doesn't have much power and while driving it won't rev over 3,000 rpm. Though while idling it will rev up to 4k without issue.

Would something like this typically a condition associated with too much fuel? Or is the timing a better place to start looking for the cause of this condition.

I double checked the lash on all the rockers while looking for a mechanical cause to the problem, and while they weren't perfectly adjusted, it was certainly close enough to get by with.

Suggestions?
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phonedawgz
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Report this Post06-05-2015 09:26 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
Things to look at

1 - Low fuel pressure - Enough to rev up the engine with no load but with a load the RPM limit drops

2 - Plugged Cat converter - If the exhaust note sounds 'wheezy' then look at this. Remove the O2 sensor from the exhaus pipe causing an exhaust leak. Then test drive. If the problem is greatly reduced that would indicate a plugged converter/exhaust.
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edfiero
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Report this Post06-06-2015 12:40 PM Click Here to See the Profile for edfieroClick Here to Email edfieroSend a Private Message to edfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks Phonedawgz, I'll check the fuel pressure.

No Cat, so I don't have that to worry about. The exhaust is puffing out the pipes with a lot of force.
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Will
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Report this Post06-06-2015 07:17 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
What ECU are you running?
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edfiero
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Report this Post06-07-2015 08:49 AM Click Here to See the Profile for edfieroClick Here to Email edfieroSend a Private Message to edfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Will:

What ECU are you running?


I have an ECU supplied by DynamicEFI, and am using their EBL Flash product. (I guess its somewhat similar to a 1227747)

I am pretty sure I am running rich based on what the O2 is showing, I'm just not sure if an overly rich condition would manifest itself in the problems I am seeing, or do I have 2 different problems.
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Will
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Report this Post06-07-2015 08:31 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
Wideband? Is the sensor it warm?

I'd go with what the O2 says.

[This message has been edited by Will (edited 06-07-2015).]

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f85gtron
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Report this Post06-08-2015 12:22 PM Click Here to See the Profile for f85gtronSend a Private Message to f85gtronEdit/Delete MessageReply w/QuoteDirect Link to This Post
I thought the whole point of the ebl flash was to tune it's own ve tables dynamically. Ebl support might be the place to start? I'm not familiar, but i looked briefly at them. They look like a great item to compliment the 7730/7747
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edfiero
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Report this Post06-08-2015 01:12 PM Click Here to See the Profile for edfieroClick Here to Email edfieroSend a Private Message to edfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Yes, EBL does allow you to 'learn' a new tune VE thru an iterative process. It is not a learn a new tune, and everything is magically corrected.

My question is specifically what would cause the symptoms that I am experiencing? No Power. No rev above 3000 when driving.
I'd kinda like to know if once I get my rich condition resolved if that will likely improve these problems, of if I will still have another problem to battle.

Fuel pressure is something that has been suggested as a potential cause. Is there anything else I should be looking at?
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f85gtron
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Report this Post06-08-2015 09:50 PM Click Here to See the Profile for f85gtronSend a Private Message to f85gtronEdit/Delete MessageReply w/QuoteDirect Link to This Post
Explain how it doesn't go over 3k. Does it cough?, backfire? Or does out simply cut off, then cut back on under 3k? (Same for 4k @ idle)

If it's coughing, backfiring....I'd look very closely at the fuel pump, also tps for bad spots.
Out it's just cutting off, stops accelerating and smoothly levels off, suspect software.

Sorry for getting off topic. I got excited when I saw the ebl part.
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