Sc400 No Power at Full Throttle
03-15-11, 04:36 PM
#1
Pole Position
Thread Starter
Sc400 No Power at Full Throttle
OK so i finally got back a 1992 Sc400. I am having a major problem,the car starts and idle perfect,if i pess the gas pedal at full throttle it breaks up and struggles to pass 2500rpm there in no smoke and it does backfire thur the intake at time. when i drive it if i go full throttle it has no power and it struggles,if i gradually press it the car will gradually pick up speed.
I have been at this for about two weeks now, i seached and read just about all the threads related to this. Here is a list of the parts i have changes so far:
Fuel pump and filter,Both Coils,Rotors & Brush,Spark plugs(the wires look good so,i didnt change them),also did 12v mod,swap the ECU(my caps were damage),cleaned IAC,disconnected TPS and AFM and there was a noticable change in the idle.
Thats all i can remember right now, PLEASE I NEED SOME HELP.
I have been at this for about two weeks now, i seached and read just about all the threads related to this. Here is a list of the parts i have changes so far:
Fuel pump and filter,Both Coils,Rotors & Brush,Spark plugs(the wires look good so,i didnt change them),also did 12v mod,swap the ECU(my caps were damage),cleaned IAC,disconnected TPS and AFM and there was a noticable change in the idle.
Thats all i can remember right now, PLEASE I NEED SOME HELP.
03-15-11, 07:47 PM
#2
sounds like your timing is off for it to backfire out the intake, pull off the upper timing belt covers and check the timing mark positions at tdc
https://www.clublexus.com/forums/ls4...-question.html
https://www.clublexus.com/forums/ls4...-question.html
Last edited by SW2UZ; 03-15-11 at 07:56 PM.
03-16-11, 11:57 AM
#3
Pole Position
Thread Starter
No not the timing already rechecked that and its on point. I pulled the plugs this morning and all the plugs are running LEAN. I pulled the fuel line to attached a pressure gauge and the was no pressure or fuel in the line. I turned on the ignition and fuel came out afetr a few seconds. I had to leave to go to work that didnt seem normal.
Any ideas ANYONE................
Any ideas ANYONE................
03-16-11, 08:13 PM
#6
ok, so new FPump & FFilter(installed correctly) and you have no/very low fuel pressure. I would look closer at the fuel pump ie is it getting full 12v due to mod are all wires/fuel line connected correctly then from there look into the possibility there is some sort of obstruction in the fuel line (you may have kinked the hardline causing blockage)
Trending Topics
03-16-11, 10:32 PM
#8
Pole Position
iTrader: (3)
Join Date: Jan 2011
Location: CA
Posts: 382
Likes: 0
Received 0 Likes
on
0 Posts
Maybe your fuel pressure regulator crapped out. Obstruction in one or more of the injectors. You said you did the fuel pump mod and you know the pump is cycling into high speed during your higher rpm's
03-16-11, 10:36 PM
#9
Pole Position
iTrader: (3)
Join Date: Jan 2011
Location: CA
Posts: 382
Likes: 0
Received 0 Likes
on
0 Posts
When you turn the key on the pump will start to prime the line. So there probably wouldn't be fuel pressure immediately. Definatly sounds like a fuel delivery problem. You can yank your injectors and have them serviced by witch hunter in Washington.
03-16-11, 11:01 PM
#11
03-17-11, 08:57 AM
#12
Lexus Test Driver
iTrader: (6)
Join Date: Aug 2008
Location: ca
Posts: 1,574
Likes: 0
Received 0 Likes
on
0 Posts
It does sound like fuel delivery problems, except for the backfiring part. If it turns out not to be, then one outside possibility to consider might be a broken cat/clogged exhaust situation. None of those really account for the backfire though; that's usually timing.
