Flashing CEL going down the freeway.

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mrmopar16
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Flashing CEL going down the freeway.

Post by mrmopar16 » Wed Nov 14, 2012 3:00 am

Hey guys.

I'm new on here, but not new to Neons. I've owned five 1st gens, and just acquired my first 2nd gen.

I picked up a 2001 Dodge Neon R/T back in May. The car went through a hail storm and had quite a few other issues with it. Long story short, I ended up pulling the engine because the #2 piston was burned up. I replaced the engine with a SOHC out of a '96 neon. I bolted literally everything that was on the old motor onto the new one. (sensors, coil pack, brackets, belts, etc.) I got everything back together and it starts and runs fantastic. However, I was driving it down the freeway today and the check engine light began to flash. It flashed 10 times and shut off. I pulled over and checked everything out. Nothing seemed out of place so I continued on my way. About another 20 minutes down the road, the same thing started to happen. Only this time it didn't shut off. I got off of the highway and babied it until I got home. (CEL turned off after I got off of the freeway). When I got home I plugged my scanning tool into the car and got a code for a multiple cylinder misfire. So, I tried switching out the coil packs (MSD and OEM types) and still got the same thing. I tried switching out the fuel rail and injectors out of another engine and still got the same thing. I bought new plugs and wires and...still got the same thing. So, i'm kind of stumped and was wondering if someone could help me out! Thanks in advance.

-Jacob

NickKo
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Post by NickKo » Wed Nov 14, 2012 7:49 am

I'm thinking your problem is coil-pack related.

I have had problems with mine, where the coil pack secondary towers, can short directly to ground via the coil pack hold-down bolts. ( I have seen the arcing / sparking with my very own eyes.)
To fix the issue, I capped off the coil pack bolts with some 3/8ths vinyl (or rubber) vacuum caps or pieces of 3/8ths vacuum hose, to provide insulation against shorting.

I don't know if this will fix your problem, but it is good 'insurance' and I do this with all my Neons, now.


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- Nick
-1998 2-dr SOHC MTX= 57mm TB; Maddog STS
-2000 Ply.LX w/MTX = Maddog STS; CAI; 2.5 exh.; 60mm T/B
-2001 ATX w/Syked PCM + Magnum header
-2001 ACR w/SRT T/B bored out to 55mm

Official "I'm Going to Drive My Neon till it Dies" Club #000009

r/tguy02
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Post by r/tguy02 » Wed Nov 14, 2012 9:11 am

you have an underdrive pulley by chance?
Justin
[02 R/T sold][00 Highline sold][04 r/t scrapped][95 NYG Sport coupe][01 r/t DD]
http://www.cardomain.com/ride/2931823

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Post by Danteneon » Wed Nov 14, 2012 11:42 am

:withstupid:

You didn't say how you were driving down the highway, but if you were getting into it and you have a UDP, that is were your problem lies. Only way to fix that is to go back to a stock pulley.
If I could just figure out how to meld the Outback and the Neon into one car...

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mrmopar16
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Post by mrmopar16 » Wed Nov 14, 2012 2:40 pm

Thanks for the info on the coil pack, Nick.

I was doing about 70 down the highway with the cruise set. It has the factory crank pulley on it.
Out of curiosity though, what would that change?

r/tguy02
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Post by r/tguy02 » Wed Nov 14, 2012 4:06 pm

the r/t pcm is very sensitive to vibration "noise", and interprets this excess vibration as a "missfire" even though it isnt. The stock drive pulley has a damper in it, whereas the aftermarket ones do not.

obviously that is not your issue though so i'd go nick's route
Justin
[02 R/T sold][00 Highline sold][04 r/t scrapped][95 NYG Sport coupe][01 r/t DD]
http://www.cardomain.com/ride/2931823

occasional demons
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Post by occasional demons » Wed Nov 14, 2012 5:06 pm

The issue with the high rpm "misfire" is more a crank oscillation thing than vibration.

Without the harmonic dampener, and the trigger wheel being at that end, the notches in the crank start oscillating, and the crank sensor sees the difference in speed as a misfire.

Unless you had it in third gear at 70, it certainly wasn't a harmonic dampener problem (Unless it is disintegrating), and I have never heard of the flashing CEL from that shutting an engine down.

If insulating the coil bolts don't do it, try the crank sensor from the '96 engine. It is the same part. They commonly go bad without setting a code. And it will shut the engine off.
Bill
Probably shouldn't listen to anything your penis says, that guy's a dick.
Patience, of course, is a very powerful weapon, but sometimes I start to regret that it is not a firearm.
Too much time spent here is a sign of a bad case of Ownaneonvirus.

2000 Neon MTX swap with '02 R/T PCM
1999 neon coupe 2.4 swap

mrmopar16
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Post by mrmopar16 » Wed Nov 14, 2012 9:20 pm

Thanks for the help guys! I guess I've got a few things to check out now.

For the record I wasn't driving it down the highway in third, haha. You said the R/T PCM is 'sensitive' to vibration...could the Polly mounts have anything to do with that? Or would it only effect the engine if I didn't have the stock crank pulley.

As for the crank sensor, the engine doesn't shut off when the light comes on. There aren't any other symptoms went he light begins to flash. (Bogging, sputtering, stalling, etc.)

occasional demons
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Re: Flashing CEL going down the freeway.

Post by occasional demons » Wed Nov 14, 2012 11:01 pm

mrmopar16 wrote: the check engine light began to flash. It flashed 10 times and shut off.

-Jacob

Well that's what I was going off of. I guess I mistook it that the engine shut off, not the CEL.

As far as the vibration, it was more towards the harmonic dampener, than loose mounts, etc. The CEL only flashes with the UDP as long as you are above 4000 to 5000 rpm. (My third gear comment) After you drop below that range, it shuts off. Then most times a solid CEL will light up with a misfire code. On mine, it was always P0302.

But as long as your dampener is intact, this shouldn't be your situation. Maybe give the belts a good look over. They are attached to the outer ring on the dampener, and therefore are part of the dampening process by default.

What brand of spark plug wires did you buy? I have had brand new cheaper auto parts store brands arcing out of the side of the insulation 10 minutes after installed.

Anymore, I stick with Bosch Premium, or Taylor, Accel, MSD, etc.

The MSD coil on the other hand is hit and miss on quality. The stock coil is about the best there is. (Price reflects it too)

You probably still have a mis fire causing the flashing CEL
Bill
Probably shouldn't listen to anything your penis says, that guy's a dick.
Patience, of course, is a very powerful weapon, but sometimes I start to regret that it is not a firearm.
Too much time spent here is a sign of a bad case of Ownaneonvirus.

2000 Neon MTX swap with '02 R/T PCM
1999 neon coupe 2.4 swap

mrmopar16
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Location: Charlotte, MI

Re: Flashing CEL going down the freeway.

Post by mrmopar16 » Thu Nov 15, 2012 2:03 pm

occasional demons wrote:
mrmopar16 wrote: the check engine light began to flash. It flashed 10 times and shut off.

-Jacob

Well that's what I was going off of. I guess I mistook it that the engine shut off, not the CEL.


What brand of spark plug wires did you buy? I have had brand new cheaper auto parts store brands arcing out of the side of the insulation 10 minutes after installed.
Oh that was my mistake. I meant the CEL shuts off.

I bought AUTOLITE wires from Advance Auto. Work has been chaotic this week so I haven't had a chance to mess with the car. But tomorrow is my way off so I'll try a few things then. Thanks again for your help!

mrmopar16
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Post by mrmopar16 » Sun Nov 18, 2012 5:40 pm

Well, I had a chance to mess with the car today. Changed the coil pack over from my 99' R/T, then put caps on the bolts to see if that changed anything..No such luck. Went through all the injector wires, and coil pack wires to see if there was a break in any of them and couldn't find anything. Soo, now i'm leaning towards it being lack of fuel pressure. (?) I'm going to borrow the fuel pressure tester from work to see what I've got.. then go from there. :banghead:

occasional demons
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Post by occasional demons » Sun Nov 18, 2012 10:04 pm

mrmopar16 wrote: There aren't any other symptoms went he light begins to flash. (Bogging, sputtering, stalling, etc.)

Well I would check the fuel pressure just to eliminate it as a source of the problem, but with the only symptom noticeable being the flashing CEL, you may have to wait until it actually sets a hard code, or hook up a scanner that can give you real time sensor inputs.


This may be one of those things that will be a PITA to figure out.
Bill
Probably shouldn't listen to anything your penis says, that guy's a dick.
Patience, of course, is a very powerful weapon, but sometimes I start to regret that it is not a firearm.
Too much time spent here is a sign of a bad case of Ownaneonvirus.

2000 Neon MTX swap with '02 R/T PCM
1999 neon coupe 2.4 swap

mrmopar16
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Posts: 21
Joined: Fri Oct 12, 2012 3:02 am
Location: Charlotte, MI

Post by mrmopar16 » Sat Nov 24, 2012 8:44 pm

So,

My dad and I took the car out for a little cruise this afternoon. We had his MatcoTools OBD scanner plugged into to, so we could record what was going on.

At 70 MPH with the cruise set everything was reading normal. (My MAP numbers were correct, Operating temp and everything else) After being on the road for a while the check engine light began to flash. When it did we noticed that the only thing that had changed with my readings was the "ST FTRM1", which had zero'd out. Without doing anything we continued driving, and after a couple minutes of the light flashing it shut off, and my ST FTRM1 readings went back to normal.

After a little research I found out that the ST FTRM1 is my 'Short Term Fuel Trim, Fuel System 1'.

Could this have something to do with my o2 sensor? Or do any of you guys have an idea of what causes this?

occasional demons
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Post by occasional demons » Sat Nov 24, 2012 8:52 pm

Possible. The upstream o2 is what the short term fuel trim is based off of. The down stream is the long term fuel trims.

But I'll let some of our more experienced tuners chime in, as there may be other inputs for fuel trims, that might affect this. Possibly an injector is leaking by randomly enough to cause this, but not enough to set another o2 code.

Hopefully it is just a bad sensor issue, and not a PCM problem.
Bill
Probably shouldn't listen to anything your penis says, that guy's a dick.
Patience, of course, is a very powerful weapon, but sometimes I start to regret that it is not a firearm.
Too much time spent here is a sign of a bad case of Ownaneonvirus.

2000 Neon MTX swap with '02 R/T PCM
1999 neon coupe 2.4 swap

mrmopar16
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Posts: 21
Joined: Fri Oct 12, 2012 3:02 am
Location: Charlotte, MI

Post by mrmopar16 » Sat Nov 24, 2012 9:02 pm

Hopefully it's not a PCM issue. :banghead:

Thanks for the quick reply!

mrmopar16
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Post by mrmopar16 » Sat Dec 01, 2012 10:00 pm

I replaced my up stream o2 sensor. Drove it for about an hour and a half without issues, then the check engine light started flashing. It went off, started flashing again then stayed on. I pulled over and did the key dance and got code po 0030. (Multiple cylinder misfire) :banghead: :banghead:

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Post by occasional demons » Sat Dec 01, 2012 10:59 pm

Does it even sound like it is sputtering in the least?

Have you tried running it with the low fuel light on to see if this happens then?

Maybe take the crank sensor out, and see if there is something stuck on the end.


Not sure if the crank pulley could be bad enough to cause the P0300, and slip from the P/S and alternator load.
Bill
Probably shouldn't listen to anything your penis says, that guy's a dick.
Patience, of course, is a very powerful weapon, but sometimes I start to regret that it is not a firearm.
Too much time spent here is a sign of a bad case of Ownaneonvirus.

2000 Neon MTX swap with '02 R/T PCM
1999 neon coupe 2.4 swap

mrmopar16
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Posts: 21
Joined: Fri Oct 12, 2012 3:02 am
Location: Charlotte, MI

Post by mrmopar16 » Sun Dec 02, 2012 12:08 am

occasional demons wrote:Does it even sound like it is sputtering in the least?

Have you tried running it with the low fuel light on to see if this happens then?

Maybe take the crank sensor out, and see if there is something stuck on the end.


Not sure if the crank pulley could be bad enough to cause the P0300, and slip from the P/S and alternator load.
No sputtering or anything..Just keeps cruising down the road like nothing is going on.

Haven't tried the low fuel thing.

Inspecting the crank sensor was the next thing on my list, too.

You think I should try swapping out the crank pulley? To me it looks like it came with the previous re-man engine. (not very old)

occasional demons
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Post by occasional demons » Sun Dec 02, 2012 12:32 am

If the pulley/dampener is newer, I wouldn't worry too much about it. But it doesn't mean it is an OEM one either. Possibly it could be a Dorman or other off brand. I really don't know that those have any issues. I do know they are not that expensive tho, FWIW.

Dealer list is $95
Rock Auto sells the Dorman for $33

According to the FSM, the misfire monitor is supposed to be ignored when the fuel level is low, so it doesn't falsely set the code with fuel starvation. Kind a dumb way to put it, as it would actually be misfiring, but the CEL would be a nuisance thing for both customers and dealers.

But I tried that route when attempting to rid myself of the flashing CEL/then solid CEL when I did have a UDP on mine. It worked for eliminating the flashing CEL for the most part.

But as soon as you restated it from the last run, the CEL would pop on. I cut the fuel sender wire, and put a 100 ohm resistor to ground, and had it on a switch. The bitch is, you cannot flip the switch at will; it must be on or off before the car is started. Once it is running, the fuel gauge will not just drop at the sudden change. In fact it wouldn't do much at all.
Bill
Probably shouldn't listen to anything your penis says, that guy's a dick.
Patience, of course, is a very powerful weapon, but sometimes I start to regret that it is not a firearm.
Too much time spent here is a sign of a bad case of Ownaneonvirus.

2000 Neon MTX swap with '02 R/T PCM
1999 neon coupe 2.4 swap

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