Post intake refresh: running lean
10-02-2018, 08:00 AM
#1
Three Wheelin'
Thread Starter
Post intake refresh: running lean
as previously mentioned, here is what has been done:
o2, CPS, knock sensors, hall sensor, MAF, flappy diaphragm, vacuum hoses,
injectors cleaned and balanced, plugs, gaskets, and other misc. as needed.
while car is running very well, I still feel, power is not up to specs.
cam timing is on the money, TPS works properly, with idle contact and WOT spot on.
fuel pressure, oil pressure, and engine temp good, as well.
after 500 miles, plugs suggest car is lean; very white and like new.
thinking of adding a few pounds fuel pressure, by adding an adjustable FPR???
any other suggestions?
o2, CPS, knock sensors, hall sensor, MAF, flappy diaphragm, vacuum hoses,
injectors cleaned and balanced, plugs, gaskets, and other misc. as needed.
while car is running very well, I still feel, power is not up to specs.
cam timing is on the money, TPS works properly, with idle contact and WOT spot on.
fuel pressure, oil pressure, and engine temp good, as well.
after 500 miles, plugs suggest car is lean; very white and like new.
thinking of adding a few pounds fuel pressure, by adding an adjustable FPR???
any other suggestions?
10-02-2018, 09:12 AM
#4
Rennlist Member
Forget the adjustable FPR- anything that is infinitely adjustable has one correct setting and an infinite number minus 1 wrong ones!
You really need positive feedback from a diagnostic tester that items like the Hall sensor and both knock sensors are working- fitting new ones is a good start but unless you know for sure they are working you are still in the dark to some extent.
Just about every engine I have owned rn well but I felt they were down on power- something wrong with the engine or something wrong with me? There is a kind of irony in that sometimes the better something works the more one feels there is something wrong. Perhaps you can post a few sample pics of the plugs. I am always deeply suspicious about peoples ability to read spark plug- I often feel they would do better reading tea leaves!
Finally just try to focus your mind on how the car ran before you started the intake refresh and try to verbailise how you feel it performs now..
You really need positive feedback from a diagnostic tester that items like the Hall sensor and both knock sensors are working- fitting new ones is a good start but unless you know for sure they are working you are still in the dark to some extent.
Just about every engine I have owned rn well but I felt they were down on power- something wrong with the engine or something wrong with me? There is a kind of irony in that sometimes the better something works the more one feels there is something wrong. Perhaps you can post a few sample pics of the plugs. I am always deeply suspicious about peoples ability to read spark plug- I often feel they would do better reading tea leaves!
Finally just try to focus your mind on how the car ran before you started the intake refresh and try to verbailise how you feel it performs now..
10-02-2018, 09:15 AM
#5
Rennlist Member
If at all possible, I'd dyno it to see what it's actually putting out versus guessing with the butt dyno which is extremely subjective.
928's are not the quickest car by a long shot.
928's are not the quickest car by a long shot.
10-02-2018, 09:39 AM
#6
Three Wheelin'
Thread Starter
You really need positive feedback from a diagnostic tester that items like the Hall sensor and both knock sensors are working- fitting new ones is a good start but unless you know for sure they are working you are still in the dark to some extent.
so, hall and knock sensors are working fine. (I assume...lol)
Just about every engine I have owned rn well but I felt they were down on power- something wrong with the engine or something wrong with me? There is a kind of irony in that sometimes the better something works the more one feels there is something wrong.
this AM, I realized the throttle plate was not FULLY open with pedal on the floor. adjusted the cables and problem solved.
also, not sure how this factors in, but this AM, temps are around 74, as opposed to usual 96. took the car for a drive, and its
a different beast. really came to life. can temps make that big a difference?? or simple cable adjusting?
will get some plug photos
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10-02-2018, 10:24 AM
#8
Rennlist Member
Plug looks perfect to me- let's see what others think.
The temperature difference you indicated makes a 3.7% difference in power output if I can still operate a calculator correctly.
The temperature difference you indicated makes a 3.7% difference in power output if I can still operate a calculator correctly.
10-02-2018, 10:25 AM
#9
Three Wheelin'
I'm in the process of putting mine back together (Intake this week)
and hopefully start it this weekend after 6 months of work.
Consequently I'm am following all these 'post intake refresh' issues very closely.
Glad you got yours sorted. Keeping my fingers crossed.
10-02-2018, 10:40 AM
#10
Three Wheelin'
Thread Starter
Consequently I'm am following all these 'post intake refresh' issues very closely.
10-02-2018, 01:06 PM
#11
Rennlist Member
No need for expensive Dyno runs unless you are building out custom engines, big waist of time and $ for you.
Plugs look fine considering the low mileage on a street car.
The only real way to know if you are Lean or Rich is to measure and log with a WBO2,
Vacuum is easy, tap in at the front FPD with a "T" fitting into a standard vacuum gauge, should be -18 to -16 at idle and as that line is a variable vacuum line, should see it go to a lower # when you hit the throttle.
Dave K
Plugs look fine considering the low mileage on a street car.
The only real way to know if you are Lean or Rich is to measure and log with a WBO2,
Vacuum is easy, tap in at the front FPD with a "T" fitting into a standard vacuum gauge, should be -18 to -16 at idle and as that line is a variable vacuum line, should see it go to a lower # when you hit the throttle.
Dave K
10-02-2018, 01:50 PM
#12
Three Wheelin'
because I thought I would be overwhelmed with the chain pads and oil pins. So maybe I'll do that next year
by simply removing the intake alone.
So where is the best take off for manifold vacuum, what you suggested or using the unused port by the TB?
Please and thanks
10-02-2018, 02:04 PM
#13
Three Wheelin'
Thread Starter
Yeah, great idea but I didn't want to get into the TB/Flappy (even Dwayne's notes and pics are quite good)
because I thought I would be overwhelmed with the chain pads and oil pins. So maybe I'll do that next year
by simply removing the intake alone.
because I thought I would be overwhelmed with the chain pads and oil pins. So maybe I'll do that next year
by simply removing the intake alone.
has a puller that he used to remove. assume that is a much easier method, not having to use a cut wheel on a Dremel??
Dave I read somewhere that manifold vacuum is different from say the vacuum coming from the egg crate canister for the Power Booster (unused ports on the 4-way split?)
So where is the best take off for manifold vacuum, what you suggested or using the unused port by the TB?
So where is the best take off for manifold vacuum, what you suggested or using the unused port by the TB?
10-02-2018, 04:19 PM
#14
Rennlist Member
" Dave I read somewhere that manifold vacuum is different from say the vacuum coming from the egg crate canister for the Power Booster (unused ports on the 4-way split?)
So where is the best take off for manifold vacuum, what you suggested or using the unused port by the TB?"
No, put a "T" in the Front Fuel Rail Dampener, easy access, would be the same as looking at the 7 way under the intake bu the MAF, good way to see if you are supplying the needed variable vacuum to the dampeners and Fuel pressure Reg.
The unused port on the 4 way by the Brake booster is a non variable constant vacuum.
So where is the best take off for manifold vacuum, what you suggested or using the unused port by the TB?"
No, put a "T" in the Front Fuel Rail Dampener, easy access, would be the same as looking at the 7 way under the intake bu the MAF, good way to see if you are supplying the needed variable vacuum to the dampeners and Fuel pressure Reg.
The unused port on the 4 way by the Brake booster is a non variable constant vacuum.