kimchee

I purchased my runner new in 2000. After putting 1000 miles on it I had the supercharger and amsoil filter added. My immediate reaction was pure joy. It felt sooo strong. It threw me into my seat and i was always accidentally chirping second gear. It ran soo smmooooth and the SC whine was music to my ears. I would cruise the freeway at 65 and punch it just to feel the acceleration to 75. I had no pinging issues and felt lucky. No surging no nothing. Drove like a new car with lots of power.

After a while the car started to feel slower. Wasnt as fun to open up and the supercharger whine wasnt accompanied with the usual seat pushing power I was used to. Is it all in my head? I dont know. But the pure joy i used to feel from flooring the car was no longer there. sigh

To make things worse weird problems started developing
A strange surge when hard accelerating. Supercharger whine sounding different. no more chirping in second gear EVER. Is it all in my head??? I still dont know but to make sure I started doing some maintanence and mods

a year ago I had the following done.
clutch changed
got a tune up
changed plugs
got my injectors cleaned
got the dynamic belt tensioner installed
along with all other regular maintanence

supercharger whine was somewhat back to normal but power still felt a little lacking. surging continued

more recently I had the following done
7th injector kit
walbro fuel pump
cleaned MAF
cleaned throttle body
replaced fuel filter
removed elbow
deckplate mod
1 step colder plugs

power is noticeable better but heres the weird thing. I feel like i only regained the power I had lost. surging is getting better and hopefully will be gone once the ecu settles down. recent occurance of the HG/LR ping is driving me nuts.


Do you guys know the feeling? The feeling that your car is losing power? Is it psychological? Is it just that ive gotten so used to the car and even though the power is the same it just doesnt feel the same? kind of like letting your friend drive your car and how it feels much faster as a passenger.

Or is there something I overlooked? The car has 54k miles on it 53k of those with the supercharger and no fuel mods. Could the o2 sensor have been damaged due to extremely high EGT? That was my next possible replacement but Id hate to keep spending money chasing ponies that were never lost.

Anyone in the San Jose, CA area that has a SCed 4runner? Want to take me for a ride and then ride mine so we can compare? All i want is ease of mind. that things are normal. Its getting too expensive trying to make my car drive the way i "think" it did 3 years ago.

In hindsight I should have dynod the car. Ill also do a dyno run in the near future but would rather put that money into an o2 sensor if I need one.

Any opinions? suggestions?
David

:edit
just in case anyone asks regarding supercharger whine.
There seems to be two distintive supercharger sounds. at boost theres the smooth whine at high rpm and the not so smooth sound at low rpm that gradually smooths out to become the high pitched whine as the rpms increase.

My memories of the SC new were that there was not much of an occurance of the not smooth whine. that almost at all rpm ranges the whine was always smooth and high pitched like u would expect.
Now even at around 3krpm if i floor it in say 3rd gear i get that not so smooth sound for a second and then it smooths out to the normal whine.

MTL_4runner

Your truck only really has 3 sensors that monitor fuel/air management in the vehicle. There is the MAF, TPS and there are (2) O2 sensors (the first of which is actually an A/F sensor not an O2 sensor.

The gradual nature of your loss of power could be due to an A/F sensor or your cat converter restricting flow.

If the S/C bypass valve was stuck that might cause some loss as well but it would cause loss of power but not the lean condition you mentioned. Stuck closed and it would not have a power problem but you might get a leanout.

shazaam

ok I'm no expert on this, and I'm new to this s/c arena myself ... so I'm just going to throw this out and see whateveryone esle thinks. Maybe its not shifting in and out of second gear properly. Meaning you need to get your valve body upgraded, that would provide those crisp shifts in gears, and also allow you to chirp the tires again. Checkout gadgets site on this and see if you can come up with anything

hecla

I just goy my s/c and lost power just like your describing. Do you have a boost gague? The line from the boost gague to the s/c came off and my gague read 0. I think it may be a vacume line or something.

Bob_98SR5

david,

there's another dave in SJ w/ an SC'd 4runner (97). his screen name is "dbui27". he hardly posts but tell him bob 98sr5 (bob kim) referred you.

bob