Hi-

We got a used '95 Neon Sport for my daughter. It had some strange problems that I fixed and it has been running fine for a while. It has about 95 K miles on it, but it still is a nice car. Last night, she called me to come and get her because the car would not run right in reverse. So I went to see what the problem was and saw that she was on an incline and that she had to back up the hill in reverse. When I tried it, sure enough, the engine lugged like crazy and shook quite a bit. You could smell gas too. We managed to get the car level and drove it home in a forward gear. It seemed to run well. By this time the check engine light was on. When I got home, I checked the Codes and found 12 and 27. The 12 seems to come up whenver anything else goes wrong, but the 27 was new to me. It has to do with the injector circuit. So this morning, I pulled the injector connector fro each injector and saw that the engine dropped RPMs significantly for each of the cylinders and the engine returned back to normal when the injector was plugged back in again. Then I pulled the negative terminal of the battery to reset the computer and when I reconnected it I saw that the check engine situation went away. So evidently, the reverse load seems to make it appear and at idle and driving in forward gears it seems fine. BTW, it is an automatic trans. So I drove to the auto oarts store and got a set of platinum plugs for it thinking that maybe I had a fouled plug. I swapped out the plugs and that made no difference. I did notice on reading the old plugs that the plug on the left as you face the engine was pretty black on the insulator whereas the others were not. Then I found a hill and tried backing up it. Sure enough the engine did exactly the same thing and the check engine light came on again. So changing the plugs really didn't accomplish anything. I cleared the computer again and ran the car at idle for a while and it seems fine and ther is no check engine light. I suspect it will come back the next time I try the reverse up a hill manuever.

So I wonder if anyone out there has seen this problem with Code 27? Has anywone had a Neon act weird in reverse? I would appreciate any help I can get. I hope to heck it is not a tranny.

Rich

 

wow that is really odd that the code only pops up when you put it in reverse. almost sounds like some wires gettin crossed there or something. im almost curious on if its the ecu causing it or not (my ecu blew two injector circuits on me once, but that wasnt tranny related at all)

sorry you put platinum plugs in there. i made a post just recently about why they are bad too

 

When you say that your ECU blew two injector cicuits, what parts got blown? As I remember what I saw in the service manual (I am at work now), the injectors get hooked up to the PCM. Is this what blew? Or did the injectors themselves somehow get fried? I pulled each injector connector and they seemed to each be working. That is the RPMs dropped when the cylinder didn't seem to be getting gas. Of course that doesn't mean that they were working right. I guess they could be running the wrong amount per cylinder, but it sure didn't seem that way. Your idea that this might be a wiring problem is interesting. Of course, I will have to think really hard about where to start looking.

So what's the deal on the platinum spark plugs? I used Bosch standard platinium plugs. These have a regular L-shaped ground conductor, but the tip inside the ceramic looks very small compared to a standard plug. I didn't get the fancy ones that have two or four ground conductors. Those were pretty pricey. The ones I got cost around the same as conventional plugs. It would be no big deal to put OEM plugs back in. I'd be curious to know what you found that is bad about the platinum ones.

Thanks for replying. It is always helpful to hear other ideas, and your thoughts about a crossed wier might turn out to be the right way to track this thing down.

 

Platinum Plugs = BAD

try reading this

 

Yeah, I read that this morning. It is very interesting. I would never have thought that this would be the case, but evidently it is. Well, I have them in there so I might as well give them a short try and I will measure the gas milage to see if there is any serious degradation. That would be indicative of poor efficiency and not firing properly. Then I'll cahnge back to the new stock plugs, the same kind that came with the car; Autolite I think. We'll check the mileage and performance again and see what we find out. I'll report the information to this Forum too.

Thanks for following up. I appreciate it.

 

I just wanted to follow up and report that the problem has been found. SlowAssNeon called it properly. Thanks SAN! I didn't have the time to debug a wiring problem so I took it to the local service station. Sure enough they found a wiring problem and fixed the problem. I don't know what it was exactly, but I will try and find out exactly what was shorted, intermittient or open. Anyway after two hours of labor, they tell me the car is AOK again. That is one heck of a lot cheaper than a transmission, a computer or injectors.

Thanks to all and especially SAN.

Rich

 

on mine, the two injector circuits that blew, were the ones inside the ecu. not cool. especially since it was a 2-week old mopar performance ecu that is now nothing more than a paperweight.

glad to hear the problem was tracked down relatively fast i know tracing a wiring issue can often be quite a task (try searching 3 days for a very very very slight fray in the wire causing it to ground out for a fuel pump wire.. that was on my '88 buick i had. not fun)