johnslee

Hi guys..my 94 sc400 giving me problem today..after a quick stop at grocery store..car startup as normal but when I step on the gas paddle..car was moving very slow..the muffler sound a little loud..and I have to step on the gas very hard (deep) in order to speed up to around 40mph...also the rpm gage acting very weird..it's idle at normal..but when I step on the gas paddle..the rpm needle went up to around 1500 when quickly drop to bottom "0" when the car speed up to 20mph or more..sometimes the rpm needle just bouncing up and down as it own will...I seem to lost power...I recheck all the plugs wires...all look good..I also replaced the 8 spark plugs...also nothing changed..car still run a little slug and loud...also when the car at the normal temperature..I can see a little steam from the back engine wall..anyone have this symptom on your car? can someone pin point me to the problem! thanks

johnslee

btw..the cell is not on..so I am not able to pull the code for it! thanks

johnslee

anyone? thanks

titanSC

My car has exactly the same problem. On all gears except D, the RPM goes up to 1.7. When I press the gas, its falls to almost 0.4, car shakes like its going to go off and then it goes back up. Its normal on neutral for a while but drops again after sometime and this keeps happening again and again. I don't have the steam issue though. Mine is a '94 too.

johnslee

I think it might be a fuel pressure problem..I just put some fuel injectors cleaner to the gas tank..i'll see if it do something to improve the problem..

Carfreak70

iTrader: (16)

Check all plugs, caps? Sounds like a ignition problem

titanSC

I'll do the same and see if it helps.

johnslee

new plugs just installed..I think it relate to the fuel pumps or fuel injection..because I can smell alot of fuel right after I start the car..I will recheck the fuel line and do so me fuel pressure testing..the problem start when I fill up the gas tank in the morning...might be a water mix in the gas..I will do more investigation..

Gspec

Sounds like a crank position sensor problem.....that would explain why the tach is messing up also.

johnslee

the car start up everytimes without problem..I don't know if that replate to crank sensor..would the "bad gas" messing up the tach too? I think I might fill up the "bad gas" at the am/pm station..I am going to empty the gas tank and try to seafoam it..will update the situtation..thanks

Gspec

I've seen CKP sensor mess up in a hundred different ways....(I'm a mechanic) Of course it's just speculation on my part based on what you told us, but that's what it sounds like to me.

titanSC

I just narrowed down the problem with my car. The RPM actually drops below 1 (to almost 0.4) only when I switch on the A/C. It doesn't happen when the A/C is switched off. But nonetheless, even this never used to happen before.

grindin8o8

so did you find the problem? what was it? i have the same symptoms as you...
-gassy smell when start up
-on idle car stalls and feels like it's going to shut off.
-exhaust sounds louder than it should
if you found away to fix it lmk. trying to figure it out too.

titanSC

Nope, my car is still is the same. I had to change the power steering pump yesterday so spent most of the time at that. I did get the car checked and it seems like it might be the MAF sensor? I don't get the gassy smell but the rest two, yeah... my distributor oil leak is next on the list (replacing o-ring), then I will look into this. I'll let you know as soon as I find a fix for it!

titanSC

I think we all have the exact same problem...

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