car cutting out under moderate load

[jjsvmax]

i have a 95 sc400 and it will drive smooth untill you try to give it more gas then it starts to buck and cut out.i changed the plugs and wires and the fuel filter. its some what better than it was.but it still does it.i dont know which way to go either a fuel problem or a electrical problem. any ideas? and a maf sensor was changed.

 

[Warm Pudgy]

check out the throttle position sensor

 

[jjsvmax]

im sorry i did replace it and adjusted it several times .

 

[Warm Pudgy]

do you notice anything while its idling?

 

[jjsvmax]

if the ac is on and at a stop, it will idle smooth and evry once and a while it will hiccup. but it is very random.

 

[Warm Pudgy]

sounds exactly like my problem, ive been at it for months trying to find the cause.
if you hold the accelerator at just the right position and just the right rpms, will the engine die down and then rev back up? is the check engine light on?


ive replaced distributor, intake gaskets (including iac, egr, and the one on the driverside of the upper manifold what ever its called), cables, plugs, tps, maf, fuel pressure regulator. nothing has made any difference. ive not been able to figure it out, and every where ive taken it has just been dumbfounded as to what the problem could be
theres no code to be pulled, no body has been able to help me

 

[jjsvmax]

no my cel is not on, but i have asked a few times and no one knows for sure. i changed the plugs and wires and it seem to help some but i think the caps and rotors may need changing. seems like a lot of work to get to the passenger side.

 

[Bushwhacker]

Sounds like the AFM to me.

 

[Warm Pudgy]

no my cel is not on, but i have asked a few times and no one knows for sure. i changed the plugs and wires and it seem to help some but i think the caps and rotors may need changing. seems like a lot of work to get to the passenger side.

nah the distributor is easy to get to on either side, just gotta take off the plastic part of the intake, then the plastic covers that cover the plugs

 

[jjsvmax]

ok ,i dont know alot of the abbreviations. so what is AFM? and what should i look for with it?

 

[Bushwhacker]

ok ,i dont know alot of the abbreviations. so what is AFM? and what should i look for with it?

Air Flow Meter. It's the silver part after the air filter housing.
There's a small black plastic unit on it with a multiplug connected.

I've replaced two of these recently for customers who had the exact same symptoms your car has, a slight 'cough' now and then when idling and jerky when trying to accelerate.

 

[jjsvmax]

ok , so today i was getting across the 4 lanes pretty quick and hit passing gear, when i let off the gas the car started a dead miss. this happened a couple of weeks ago , and thats when i changed the plugs and wires, which did not help. but it eventually just went away. could something get plugged. or could a injector just stop and start?

 

[Warm Pudgy]

thats a good question
i think you might be able to find out which injectors are working or not by touching a long screwdriver to each and putting it to your ear and listening for irregularities
from my understanding they should make a consistent ticking

 

[jjsvmax]

i will try that,,thanks

 

[-Nemesis-]

If you can't get close enough with a screw driver, try a length of normal garden hose, the old bush mechanic stethascope

 

[jjsvmax]

i went and bought a stethiscope and all the injectors had a constant clicking , some were louder than others. would a clogged up in tank strainer cause it to run bad? when i changed the inline filter , the gas i poured out was really dark and nasty looking.

 

[Warm Pudgy]

did you rev it up when listening to them?

 

[jjsvmax]

no i didnt

 

[jjsvmax]

well i did rev the motor and all were clicking , some louder than others. change the fuel strainer in the tank, no change. it still has the miss.

 

[jjsvmax]

think i will get a yugo