Dtwillis5

The car star up and kill at 17000 rpm I change the mass air flow sensor thats wasnt the problem. The car been sitting for a while
What could be the problem?
94 ls400 87000 miles

andyman32

I'm assuming you mean 1700, not 17,000. If your car hits 17,000 RPMs and doesn't explode, that's a miracle.

Does the car start & idle, then when you press on the accelerator it cuts out? Or does it cut out immediately after startup, before the engine settles to idle speed?

Also, when it cuts out, does it kind of sputter and die, or does it just cut out very quickly and quietly?

Raddison

That is quite an engine.

But really, more detail is needed to help diagnosis

Dtwillis5

Yea 1700 rpm it start up and it will run all day, but when I press the gas it kill ASAP I have to ease it to 1700 rpm. It sputter and kill

andyman32

Ok, you're down to a different set of problems. "Sputter and die" almost certainly means you're having a fuel delivery problem. I've seen elsewhere on this forum that there are two fuel pumps in these cars (not uncommon for 'hungry' vehicles, though perhaps for a simple naturally-aspirated V8 like this)... I'd wager you have one of the following:

- Clogged fuel filter - if you haven't changed it yet, change it anyway, regardless of this problem
- one or two weakened or failing fuel pumps
- ruptured fuel pressure regulator

There is also the possibility that there is a failure in a sensor somewhere, either in the throttle position sensor or perhaps in the crankshaft position sensor. The crank sensor has been known to kill the motor on other kinds of cars. However, that's a clean, silent kill - not a sputter-and-die.

Also - I think it's fuel delivery because if it were an air (vacuum) leak it would almost certainly cause rough running throughout the drive cycle, including starting and idling.

The best bet at this point is to do (or have done) a fuel pressure test on the fuel rail. If the fuel pressure is out of spec (don't have specs handy but you can probably find them here or on alldata) you're probably just running out of fuel when the engine spins up.

Good luck!

Dtwillis5

Update!!! The car getting gas and the timing is on. Its getting spark from every spark plug and when I put it 2 or L position it rev up all the way. White smoke come out the pipes and gas leak from the catalytic converter. I'm lost

BrittonJ85

Have you changed your PCV value?

Dtwillis5

No. What are symptoms of a bad PVC valve? Cause ill change it today!

deanshark

I still don't understand this leaking gas from catalytic converter. Are you saying gasoline is leaking out of your exhaust? Wouldn't that start a fire and blow your car up? If there's gasoline in the exhaust then you have a serious problem. I think your engine dieing at 1700 is an ignition problem, mine did the exact same thing when the timing was off. Do you have spark at all 8 plugs, (not just the wires) good spark? Are any of the spark plugs wet (with fuel) when you pull them out to check spark? That would indicate not enough spark.

LEXTEK1

Yep, thats a shorted injector driver in the ECU! You can fix this if you have some soldering skills and patience. Let me know if you want instructions......

P.S. There are NOT two fuel pumps on this car. There is ONE fuel pump with TWO speeds!

Dtwillis5

Yeah I could use the instructions. My momma good with soldering. Probably y my battery be going dead

Dtwillis5

when I put it In drive 2 or L the rpms go up like a normal car.

deanshark

Maybe is whatever in the ECU like LEXTEK1 mentioned. But I would think if the ECU was bad in any way there would still be a code.

LEXTEK1

Your ECU is probably affected in many ways. In a nutshell. Remove the ECU. Take it apart and clean the brown goo out of the circuit boards with a q-tip and alcohol.Replace the capacitors and give it a try. There are no guarantees that the ECU circuits are not beyond cleaning. In your case, pay close attention to the black chips that stick up on the board and clean between them well. This is where your gas problem is.

LEXTEK1

Ya think? When was the last time you saw fuel leaking from the cats? What code would you expect to see? Injector hung open code perhaps!