My 1995 Neon has an engine management issue, the most salient symptom of which is that, upon reaching a certain temperature (about ? way between hot and cold, in the same spot every time), it begins to think it?s an old Charger with a huge cam and idle as if on the verge of stalling. In motion, it then confuses the accelerator with the brake, slowing noticably when I give it a little gas. However, when I just floor it, it roars to life for about long enough to get everyone behind me to lay off their horns, but the fuel flow ceases again shortly thereafter and I?m forced once again to slam my foot in the tank and imagine what surrounding drivers must be thinking??hmm?can?t afford a better midlife crisis that that?!? I don?t know, maybe I look young enough to pass for immature, but still?
I?ve noticed that if, before driving, I allow the engine to idle its way to the temperature I mentioned earlier, the symptoms occur only rarely. However, I can neglect the warmup and, maybe about half the time, enjoy trouble-free motoring. I haven?t been able to determine any consistent effects of weather, but I?ve only had the car since October, which is more or less the beginning of Winter here in Detroit.
I?ve been unable to determine any firm constants in this equation, and the extent of my luck with the local wrenches is that they?ve been honest enough to admit they haven?t a clue. I hope you can shed some light on this matter. Thanks.
Mike Switney
m.kent1@yahoo.com
313-903-0156
Sounds like a possible throttle position sensor. If when you hit the gas the TPS isn’t telling the ECU, the throttle plate will open, the injector pulse width will remain short and far spaced, and you’ll bog down from starvation. Then, perhaps when you floor it it begins to respond with a signal, the injectors open up, you peel rubber, the horn blowing stops, and shortly thereafter it malfunctions again.
Just a wild guess.
There may be two problems: the tps (throttle position sensor), as mb says, and the cts (coolant temperature sensor). The temperature signal from the cts is the main way the computer knows the temperature of the engine. It uses that information to control fuel and bypass air (via the iac (idle air control) valve sent into the engine. A messed up signal, messes up the air/fuel mix, and causes performance problems.
If memory serves correctly, the Dodge Neon is one of the few 1995 cars which had OBD II engine management system. Auto Zone, or other auto parts store can scan for the check engine light (free). It is on, isn’t it?
Yes, the TPS but also the CKS (crankshaft position sensor) often get flaky on these cars but don’t cause the CEL to come on. Many Neon owners simply replace both and yell “cured!” Get a better idea of your situation by asking the Neon specialists at http://forums.neons.org/viewforum.php?f=1.