Strange Hesitation Sensation In My Car

[Mr_Chunkz]

So shortly after adding my MSD DIS4 and changing the plugs to standard plugs ( not iridium ) my car has felt sort of wierd. Between 40%-100% Throttle position ( about less than half to WOT ) my car will pick up at first like normal, but then will hesitate for a second, and then continue like nothing has happened. I felt a sensation similar to this when I had blown knock sensors but the hesitation with the blown knock sensors was much much more extreme and lasted all the way to redline.

I guess this could be best described as the car feels like its retarding timing. This happens at any rpm. My best explanation is that the MSD DIS4 messes with advancing and retarding ignition timing and that the AFC Neo im running is tuned to the stock ignition, so Im going in for a retune ( also retuning since I purchased 6PSI pulley )


Does anyone else have any thoughts on the subject?

[Eye8Pussies]

hmmm....that is very hard to say...it could be two things- ignition or fuel. But since it's a small hesitation, it's most likely ignition. Too bad you don't have a wideband otherwise, you could tell if you have a misfire or a timing effect

I wouldn't be surprised if the ignition is being affected by the msd unit, but it wouldn't have anything to do with your neo and how that's tuned though

[SolaraBlue]

had the same problem a couple times. turned out to be the spark plugs (1st time) and the coil packs (2nd time) check either of those places first. i'd bet on your spark plugs.

[Mr_Chunkz]

i had iridium plugs before and replaced them, as I was told that iridium plugs cannot be used with MSD ignition. Im running some pretty cheap bare standard plugs right now.

[Eye8Pussies]

what's standard? platinum?

you can always try copper plugs since they have the best conductivity- they just don't last long

[Midias]

^^ your not running bosch are you.

[Jakecallun20]

^^ your not running bosch are you.

Yeah, Do not run bosch plugs. Toyotas HATE bosch.

[Midias]

If you are running bosch now and are looking for plain plugs try NGK V power I always liked those in my Accord with an msd.

[Mr_Chunkz]

im running NGK Part number BKR6EYA

[Mr_Chunkz]

Found cause of hesitation
my car was running very very lean
17.1AFR in fact. The guys at the dyno shop told me that it wasnt safe for me to run my car hard ( oops ) but fixed it all up for me

New dyno showed 250.1 Ft/Lb TQ @ Wheels @ 3300rpm but I couldnt get an accurate peak power reading because my 5.5 belt slipped on my 6psi pulley. The power stops climbing @ 216WHP but im sure the car has much much more to give.

[Dawgz]

Found cause of hesitation
my car was running very very lean
17.1AFR in fact. The guys at the dyno shop told me that it wasnt safe for me to run my car hard ( oops ) but fixed it all up for me

New dyno showed 250.1 Ft/Lb TQ @ Wheels @ 3300rpm but I couldnt get an accurate peak power reading because my 5.5 belt slipped on my 6psi pulley. The power stops climbing @ 216WHP but im sure the car has much much more to give.

can u post the dyno sheet?

[Mr_Chunkz]

Found cause of hesitation
my car was running very very lean
17.1AFR in fact. The guys at the dyno shop told me that it wasnt safe for me to run my car hard ( oops ) but fixed it all up for me

New dyno showed 250.1 Ft/Lb TQ @ Wheels @ 3300rpm but I couldnt get an accurate peak power reading because my 5.5 belt slipped on my 6psi pulley. The power stops climbing @ 216WHP but im sure the car has much much more to give.

can u post the dyno sheet?

uh well its kind of a pain in the as.s but sure i guess i can

[Mr_Chunkz]

Torque Chart
Baseline Run - Bottom line
Rough Tuned - Middle Line
Fine Tune - Top Line
This graph is representative of Lb/Ft @ Wheels at 3 different levels of the tuning stage, baseline ( untuned ), rough ( general ), and fine ( specific tune )

While it may seem my fine tune runs 277.2 lb/ft for a second i was told my peak tq was actually 250.1, as indicated by the notch


Torque Numbers
Baseline Run - Top number
Final Run - Bottom Number
This is self explanitory. Its how much torque i made at the wheels at the beginning of the tuning session and at the end of the tuning session.

Baseline tq was incredibly low, as you can imagine
after some proper tuning, the best tq figure was established with a final run of 250.1 Ft/Lb TQ


WHP Chart
Baseline Run - Bottom line
Rough Tuned - Middle Line
Fine Tune - Top Line
This graph is representative of WHP at 3 different levels of the tuning stage, baseline ( untuned ), rough ( general ), and fine ( specific tune )

Here is the chart for my HP, notice the curve dropping off after 5200-5500 rpms. Boost was dropping from 6PSI to 4.5-4.7PSI due to a slipping SC belt.

WHP Numbers
Baseline Run - Top number
Final Run - Bottom Number

Pathetic peak hp numbers from slipping belt and loss of boost at the top end.


This graph shows exactly where the boost dropped off during the run, causing a plateau in power delivery and a steady dip down. This loss of power occurs at peak WHP moments in the powerband, resulting in a low Peak WHP

[Eye8Pussies]

sorry...that is really hard to make heads or tails of....could you just take a snapshot of the entire page so that we can read it and see what's going on?

every snapshot you show looks very similar, so it's hard to compare the lines to the numbers

[Dawgz]

or...buy a scanner...lol, im kiddingggg