misc..
09-17-02, 10:39 AM
#1
Guest
Posts: n/a
misc..
Yesteday I went over to TM engineering in carson and spoke with Todd. What a knowledgeable guy! They have some crazy stuff planned for the future.
He mentioned that the LS and SC computers are very sensitive to modfications, and the engine actually hardly ever benfits from intakes and exhaust systems. He siad he tried different combinations with th air filter on an SC4 and from all his tests the car actually ran worse. From what he said the ECU is too sensitive for it's own good. So lookout for a good ECU upgrade from these guys sometime soon. They are planning it.
I asked him to check out the classic hesitation start (around 1100RPMS for me) and if he thought it was the torque convertor. Most likely he told me that it's not the transmission or TC, but something to do with the intake and the car dropping it's timing / or cutting fuel to compensate for the increased and hotter airflow (no cold air box on mine) I got a similar answer from the MK auto place I took my car to, he said it might be fuel injectors, MAF sensor, or the fuel pump.
This still doesn't explain why I can't peel out just by flooring the car anymore. I really think it has something t odo with the transmission. I'm going to try and remove the K&N filter and go back to a stock filter. See if I can chirp the tires from then.
Anyway..
He mentioned that the LS and SC computers are very sensitive to modfications, and the engine actually hardly ever benfits from intakes and exhaust systems. He siad he tried different combinations with th air filter on an SC4 and from all his tests the car actually ran worse. From what he said the ECU is too sensitive for it's own good. So lookout for a good ECU upgrade from these guys sometime soon. They are planning it.
I asked him to check out the classic hesitation start (around 1100RPMS for me) and if he thought it was the torque convertor. Most likely he told me that it's not the transmission or TC, but something to do with the intake and the car dropping it's timing / or cutting fuel to compensate for the increased and hotter airflow (no cold air box on mine) I got a similar answer from the MK auto place I took my car to, he said it might be fuel injectors, MAF sensor, or the fuel pump.
This still doesn't explain why I can't peel out just by flooring the car anymore. I really think it has something t odo with the transmission. I'm going to try and remove the K&N filter and go back to a stock filter. See if I can chirp the tires from then.
Anyway..
09-17-02, 04:50 PM
#3
I have a huge project next year for my engine, but my ideas will be a secret hehe, I might plan on getting some suggestions from Todd at TM once the first phase is accoplished.
Once my rims come in next month hopefully "keeps crossing fingers" I am working on my exterior upgrades for the rest of the year, I only have a few items lefted to do. I just finished my audio/video theater so that is taken care of.
Then I am going to move on to performance.
I have an air intake and exhausts with no resonators and I can still chirp my tires every time if i wanted from stop and even in motion in 2nd gear maybe once in a while, but I have done it before unless i was hearing things lol...
Oh yeah btw keep us posted on the upgrade ECU.
Once my rims come in next month hopefully "keeps crossing fingers" I am working on my exterior upgrades for the rest of the year, I only have a few items lefted to do. I just finished my audio/video theater so that is taken care of.
Then I am going to move on to performance.
I have an air intake and exhausts with no resonators and I can still chirp my tires every time if i wanted from stop and even in motion in 2nd gear maybe once in a while, but I have done it before unless i was hearing things lol...
Oh yeah btw keep us posted on the upgrade ECU.
Last edited by LOTC; 09-17-02 at 04:57 PM.
09-18-02, 12:29 AM
#4
Guest
Posts: n/a
OK, I've been driving around testing stuff..
I noticed that sometimes, and I can't duplicate it, but there is about 200-400 RPM's space from the lowest idle in drive and when I push and the gas and something happens. I can hear the differential locking into place and for the first time I could reallly hear it starting and stopping. Makes a loud clunk noise.
Also If I hold down the brakes and give it gas, that same 200-400 RPM space(from 600-1000) *barely* makes the car surge. I think my problem is a combination of the torque convertor, differential, and possibly those other things such as the K&N (and maybe the MAF) fuel injectors, and maybe even the valves are out of adjustment (?). I hink it's mainly a transmission problem.
I know somethings wrong when I used to be able to burn out for a couple feet just by flooring it, now I just hear gggggggggggrrrunnnt.
I noticed that sometimes, and I can't duplicate it, but there is about 200-400 RPM's space from the lowest idle in drive and when I push and the gas and something happens. I can hear the differential locking into place and for the first time I could reallly hear it starting and stopping. Makes a loud clunk noise.
Also If I hold down the brakes and give it gas, that same 200-400 RPM space(from 600-1000) *barely* makes the car surge. I think my problem is a combination of the torque convertor, differential, and possibly those other things such as the K&N (and maybe the MAF) fuel injectors, and maybe even the valves are out of adjustment (?). I hink it's mainly a transmission problem.
I know somethings wrong when I used to be able to burn out for a couple feet just by flooring it, now I just hear gggggggggggrrrunnnt.
09-19-02, 12:51 AM
#6
Guest
Posts: n/a
Blah!
Today on the freeway I could replicate that held stutter in the transmission so I called up Todd (at TM) and asked him to take a look and see what I found.
I can hold the RPM's at like 1100 or so in 1st gear up to 25 mph and I get this bucking sensation. Todd noticed it (at least he told me he did ;-) ) and I pointed out the 'waving RPM' thing when the stuttering occurs. Basically the RPM's move up and down rapidly in 50-100 rpm movements. Enough to see on the tach.
Todd didn't have any ideas, but he said he had a spare torque convertor laying around he'd be willing to sell. I'm going to check out some installation prices and most likely I'll pick it up.
HMMMMM
Today on the freeway I could replicate that held stutter in the transmission so I called up Todd (at TM) and asked him to take a look and see what I found.
I can hold the RPM's at like 1100 or so in 1st gear up to 25 mph and I get this bucking sensation. Todd noticed it (at least he told me he did ;-) ) and I pointed out the 'waving RPM' thing when the stuttering occurs. Basically the RPM's move up and down rapidly in 50-100 rpm movements. Enough to see on the tach.
Todd didn't have any ideas, but he said he had a spare torque convertor laying around he'd be willing to sell. I'm going to check out some installation prices and most likely I'll pick it up.
HMMMMM
09-19-02, 03:08 AM
#7
Guest
Posts: n/a
wait!
It's my engine!
I just sat and very lightly revved my engine for a few minutes. Suprisingly the stuttering and vibrations happen while the car is in neutral / park!
I'm very suprised now, wondering what the hell it is. I'm going to go with Todd's advice and put the stock airbox back on and see what happens asap.
VERY lightly pushing on the gas and keeping the RPM's below 1000 I get the same feeling as I do while driving.
The engine shakes, when I let off the gas, and at certain points in between 600-1000 rpm. They also drop if I hold the gas at a point, then it feels like it's stalling then pops up higher quickly.
OK, either spark plugs, fuel (i think it is) or MAF..yes I think my TC is worn, but now I've singled this down to some kind of engine thing, (I think) ehh..with the suggestions from Todd.
I just sat and very lightly revved my engine for a few minutes. Suprisingly the stuttering and vibrations happen while the car is in neutral / park!
I'm very suprised now, wondering what the hell it is. I'm going to go with Todd's advice and put the stock airbox back on and see what happens asap.
VERY lightly pushing on the gas and keeping the RPM's below 1000 I get the same feeling as I do while driving.
The engine shakes, when I let off the gas, and at certain points in between 600-1000 rpm. They also drop if I hold the gas at a point, then it feels like it's stalling then pops up higher quickly.
OK, either spark plugs, fuel (i think it is) or MAF..yes I think my TC is worn, but now I've singled this down to some kind of engine thing, (I think) ehh..with the suggestions from Todd.
Trending Topics
09-19-02, 12:39 PM
#8
Rookie
Join Date: Aug 2002
Location: NYC/NJ
Posts: 96
Likes: 0
Received 0 Likes
on
0 Posts
Just an FYI, but Todd at TM Engineering has won several IASCA Championships, and is rather famous for that. At least that's how I found out about TM Engineering. Great guy, and very, VERY knowledgable.
09-19-02, 12:53 PM
#9
Lexus Champion
Well, regarding modifying the air inlet and the ECU... I notice you are running a "pod" type intake. This could be disrupting the air flow through the meter and causing a unstable signal. Whether or not this is causing your particular problem I do not know but I would guess this could be what Todd experienced. This, and the cold air vs. hot air situation is why I modified the stock box. My mods are shown in my post https://www.clublexus.com/forums/sho...threadid=55111 and very good instructions and specs for the SC can be had at http://www.users.bigpond.com/pgscott/BFIDIY.html
I have had no problems and picked up apx 7hp at the engine. This was determined with back to back testing with multiple runs at the drag strip. Real performance is the goal not just "it feels faster" or "it sounds faster" I want it IS faster
I have had no problems and picked up apx 7hp at the engine. This was determined with back to back testing with multiple runs at the drag strip. Real performance is the goal not just "it feels faster" or "it sounds faster" I want it IS faster
09-23-02, 07:08 PM
#11
Driver School Candidate
Join Date: Sep 2002
Location: Oregon
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Something that I have not read about lately in this forum,
(but run into quite a bit a few years ago), is the problem of carbon build up in the combustion chambers. This would cause driveability problems, because the carbon would abosorb the gas and cause the engine to run lean when cold (although I can imagine this also causing a problem when worm at low RPMs).
Another thing that made a world of difference for me at low RPM/idle was cleaning the throttle body. Gunk builds up in the throttle body area causing the buttler fly to stop at different positions when closed, or stay partially open.
I hope this helps.
(but run into quite a bit a few years ago), is the problem of carbon build up in the combustion chambers. This would cause driveability problems, because the carbon would abosorb the gas and cause the engine to run lean when cold (although I can imagine this also causing a problem when worm at low RPMs).
Another thing that made a world of difference for me at low RPM/idle was cleaning the throttle body. Gunk builds up in the throttle body area causing the buttler fly to stop at different positions when closed, or stay partially open.
I hope this helps.
Thread
Thread Starter
Forum
Replies
Last Post
