My friend right now is stranded, after a 2 hr drive in his neon all of a sudden the engine dropped to idle and the gas peddle no longer worked, the brakes and power steering also locked up so he had to coast himself to a stop. Now after letting everything sit for quite a while the car turns on in park and idles fine but as soon as he puts it into drive the engine stalls. After several attempts it finally works again in drive but after a few minutes the engine drops to idle speeds and the brakes and power steering lock up. The only things that I could think of is a clogged/dirty/bad IAC or a locked torque converter. Any ideas?

 

now when you say the brakes and power steering "locked up" it sounds like you mean they stopped working which all sounds to me like you have a major vacuum leak but i'm not an expert just my thought.

 

By locked I mean the brakes became hard to press and the steering became stiff. Now when the engine idles it seems to go up and down in rpm and if the engine is warm as soon as the gear in changed to drive or reverse it instantly dies, but if the engine is cold when switched to drive or reverse it will drive for a bit then instantly die.

 

Can you rev the engine when it's in park? Or does it not want to rev up?

Does it stall when you try to rev it in park?

If it stalls, It sounds like you either have low fuel pressure or, a defective MAP sensor.

You could try unplugging the MAP sensor, to see if it stays running any better with it unplugged.

 

Revs fine in park. Fuel pressure is around 55psi. It only stalls when being switched into park or reverse. The idle is very chippy the revs go up and down constantly.

 

You mean it stalls when shifting into drive or reverse only?

Is the idle chippy when it's in park too?

If so, check for vacuum leaks and the throttle position sensor, and the MAP sensor.

If the check engine light is on you should check and see what codes are stored.

 

Yes shifting to drive or reverse when warms causes it to stall. The idle is very bad in park the rps go up and down it sounds like its about to die then it speeds up then back down again and this repeats.

I cant find any vacuum leaks and I plan on cleaning the MAP sensor today.
Fuel pressure comes out to around 60 psi and I've tried cleaning the IAC which resulted in no change.

How should I go about checking the TPS sensor?

One last thing I should add is previously before this incident the cars oil light came on every time the vehicle came to a stop but as soon as it started driving again the light went off this only happened once the car had ample time to warm up and yes I have checked oil level and its right on mark, I don't feel the oil pump is the culprit either because i've checked all the clearances previously and they were all well within spec. The oil light actually got me into also thinking the IAC is the culprit. The reason being is I feel that once the oil warms it becomes less viscous as a result when pumped at lower speeds it doesn't build up as much pressure and triggers the oil pressure sensor. I feel that when the car comes to a stop the idle may have been too low resulting in the pump not spinning fast enough to build up enough pressure and thus triggering the sensor but as soon as the car got off stop and started to drive again the pump picked up speed and generated enough pressure to make the oil light to go off.

 

Well I think me and my friend are both about to give up on this car and junk it. A year ago he drove through a large puddle of water ended up hydrolocking the engine bending a rod, spinning a bearing and scoring the crank. We got new rods pistons and a remanufactured crank. We took it to the machine shop got the rotating assembly balanced and all the parts cleaned. The bottom end was all assembled with new gaskets, bearings, main bolts, rod bolts and water pump, the oil pump was reused because all of the clearances checked out. All new gaskets on the top end as well, the valves were all removed, cleaned and reinstalled. We had to get a new camshaft because the original one had pitting due to rust buildup. Oxygen sensor was replaced also. Now here we are, it started up and ran fine after it was all put back in, fuel pressure registered around 60 psi each cylinder get around 130psi. But for some reason after his 2 hour trip something happend which caused this problem to happen.

I replaced the IAC and there are no changes. The MAP sensor was cleaned and still no changes. I raised the idle screw up slightly and the car idled much faster and when put in reverse rpm dipped down to almost stalling then back up again then down to almost stalling back up and finally it stalled (instead of just stalling instantly) I adjusted the screw back to its defult. Unplugged the MAP sensor nothing happened unplugged the TPS idle got incredibly rough almost as if about to stall, kept TPS plugged in but removed it from throttle and idle got slightly smoother but engine still stalled when put into reverse. I purchased a new TPS but it had the wrong connector type for being plugged into the wires even though it was supposed to be the correct one so i had to return it. I don't even know if I should bother looking for a different TPS because im not sure if that's even the problem and I don't want to waste any more money on this. Sometimes after the engine warms up and stalls the car refuses to start again until it cools down.

Now here I am and I have absolutely no idea on how to move forward.

 

When all the sensors are plugged in and you reset the PCM by disconnecting the battery cable.

Does the check engine light turn on shortly after restarting the engine?

If it does did you check the stored codes?

 

So i did the key trick as the car was from yesterday and got p codes:

1684: Battery Loss in the Last 50 Starts The battery has been disconnected within the last 50 starts
0123: Throttle Position Sensor Voltage High Throttle position sensor input above the maximum acceptable voltage range
0108: MAP Sensor Voltage Too High MAP sensor input above maximum acceptable voltage
0320: No Crank Reference Signal at PCM No reference signal (crankshaft position sensor) detected during engine cranking
0508: Idle Air Control Motor Circuit Low Idle Air Control Motor Circuit below acceptable current

then I went to disconnect the battery and waited a few minutes then reconnected did key trick again and got codes:

1684: Battery Loss in the Last 50 Starts The battery has been disconnected within the last 50 starts
0123: Throttle Position Sensor Voltage High Throttle position sensor input above the maximum acceptable voltage range
0108: MAP Sensor Voltage Too High MAP sensor input above maximum acceptable voltage
0320: No Crank Reference Signal at PCM No reference signal (crankshaft position sensor) detected during engine cranking
0508: Idle Air Control Motor Circuit Low Idle Air Control Motor Circuit below acceptable current

Then I started the engine and let it idle for a few moments in park and did the trick again and only got code:

1684: Battery Loss in the Last 50 Starts The battery has been disconnected within the last 50 starts

Code 0320 makes me wonder because it was not unplugged at all, why would it even come up but then no longer be present.
I also want to note something that i did not try before. I turned the steering wheel while the car was in park and the engine sounded like it was about to stall then I turned it further and the car stalled.

This leads me to believe that what is wrong is that the engine is not receiving the proper amount of fuel and or air.