I have a '97 Neon Highline with a DOHC that I have owned since new. It is a great car and now has a grand total of 72,000 mi.
Last fall it developed a perplexing intermittent starting problem.
It would fail to start in the morning, usually after a large temperature difference (warm day, cool night).
When it failed to start, I would notice that the "check engine" light would not come on in the "on" position as it should, and no buzz from the fuel pump leaving me to believe that the computer was not getting power from the ignition switch.
I replaced the switch and the problem went away, for a year. Now here it is the same kind of weather and the exact same problem.
I removed, disassembled and inspected the contacts inside the switch and nothing looks suspect, no corrosion, no evidence of arcing. Wiring to the switch is perfect and I checked my grounds to body and to computer. I cannot get this car to fail in any predictable manner so it really leaves me at a loss.
Anyone ever had anything like this happen to them???

 

check out the fuses and relays....

 

WHen was your last tune up or overhaul?

 

July, it got plugs, wires, timing belt, water pump, valve cover gasket and a coolant change.
We bought this car new and I am a freak about maintenance.

I think I may have found the cause but I am not ready to brag about it yet, I will give it a few more days and then I will share with the class.

 

aight dude any updates as to what you did my 97 dohc neon is doing the same thing and i need to fix this thing asap... any info to even give an area to start would be helpfull

 

I would love to tell you that I methodically tracked the problem and solved it. But I haven't.

The last time it screwed up I used my meter to trace the power all the way back to the computer. I removed the computer to check the capacitors and couldn't because the board is sealed in gel, I assumed it had to be a computer issue. I cleaned the computer and sprayed the inside of the connectors with WD40 and put it in front of a heater to completely dry out. I put it back in and then found a replacement computer on Craigslist.

The new computer now sits by my door where it has been for two weeks, ready to be thrown in upon failure to start, which has still yet to occur despite much lower temps and precipitation. I can't advise cleaning the computer because I can't think of a logical reason for it to have worked but it was either that or the moving of the wires that went to it.

 

On a side note, the coil can fail and gives no codes when it does. Rather than hase through wires, my coil gets replaced with a junk yard unit from a 2G neon or stratus. Far cheaper than anywhere else, and give piece of mind. Connector is an easy swap for 95 and 96 neons. 97+ have same connector.

 

the problem isn't the coil I have spark... my fuel pump isn't kicking on when the car won't start... but when it does the fuel pump works fine... i kinda think its my crank sensor but that wouldn't explain why it works sometimes and not others...so it all kinda leads right to the pcm being screwed up some how....

 

It is not the crank sensor, if you have spark. Pump could be on its way out.

 

Check the relay first.

I agree on the pump. I forgot that I chased my tail on that problem like three years ago. It also led me to fix a problem that was more of an inconvenience that a real issue but aggravating all the same.

From nearly day one, on hot days the car would not want to start the first time you turned the key, but I found if you turned the key on,off,on the fuel pump seemed to change pitch the second time and would start then. The fuel pressure was bleeding off.
I bought a new filter/accumulator - $65 and no help. So being that it only did it on really hot days, I lived with it for a while. Then one day no start and no fuel pump buzz.

So this was the time to get to the bottom of the weird hot days problem. I bought a new pump and set about to change it. I discovered several things about the fuel system at that time. First the plastic pump housing/ gauge sending unit is articulated with O-rings in it that can and do fail. Second that the fuel system on my 97 has no return line and all fuel pressure regulation is done right there at the tank by a little round metal cylinder that spins into the top of the unit, which also has o-rings that fail. This allows gas to drain back to the tank and keep no pressure in the line.

When you turn the key on it just pulses the pump to top off the pressure, that is assuming that you had some pressure to begin with.