My SC400 Won't start or Idle unless Brake is Applied

[O.G.]

I have a 1992 Lexus SC400. Had the timing chain, water pump, tensioners, etc. replaced as well as the coils, distributor cap, one of the rotors, wires and plugs replaced as well. Car ran great. Got in it to crank it up and it would crank up and fall dead. I checked the MAF, still nothing. Happened to crank it up and left my foot on the brake and it starts and stays running. As soon as my foot is almost off the brake, it falls dead. I spent all day today screw with trying to get the MAF screws off to replace the MAF with another one. Does anyone have a clue what the hell is going on with this car. This is my first SC400 and from the looks of things, my last. I'm getting frustrated with this car. Let me know, thanks in advance.

 

[gloverman]

Did it happen just after doing the timing belt? Who did the belt etc? Cheer

 

[O.G.]

It happened after doing the timing belt. With the Brake pressed down, the car will stay on and rev all day.

 

[gloverman]

Who did the timing belt?

 

[viki drifter]

check your vacuum hoses..or air related hoses for crack or torn... b4 checkin the timing belt.

 

[O.G.]

A professional Lexus certified shop. This thing just started doing this this week. I will check for cracked hoses. Can anyone Tell me where I can get a diagram of all the vaccum hoses?

 

[sideshow]

do your brake lights work properly
maybe u got bad earth and when u press brakes
helping the circuit
try unplugging the brake switch and see if the car stalls
all the time or see if it makes a difference
prob a long shot but if it's something to do with brake pedal
take a look at that

 

[gloverman]

I am wondering if one of the coil plugs are not pushed on fully or damaged. While other problems often seem to show their ugly head when work gets done it seems most likely that it is related to the work that has been done. It doesnt need to MAF to run. It basicly needs to see crank and one cam to start and then everything else to make it run correctly. Another signal toyotas need is the feedback loop from the ignitors which is related to the coils. This is why I suspect an issue there. Sideshow is correct on checking the brake lights as power is fed from the stop light switch to the ECU to allow nice downshifts when braking. It might be backfeeding through this too. Pretty strange issue.

 

[sideshow]

u could be right kelvin
so many times it's

 

[sideshow]

oops bloody iPhone buttons to close
u might be right kelvin
so many times it's coil at fault or unplugged
but when people describe the problem on here
they never mention its missing
I guess unless u work on em regularly u don't know
difference between running on 2 coils or 1 coil
usual problem is they forget to plug front coil harness on left side
or they leave right coil plug off