So I'm not the greatest at driving stick. Especially when I'm trying to get on it a little bit.
Over the past couple days, I've noticed something. Sometimes, when shifting from 1st to 2nd, if I don't do a very good job with the clutch and the car jerks a decent amount, the check engine light will flash. Or, rather flicker. It flicks on and off once or twice with no apparent rhythm or pattern. It only does it while the car is jerking, and never does it on smooth shifts or after the car smooths out from a bad one.
Today something else happened too. I was driving it around and decided to be stupid and try to give it some gas. NOTE: After this, I'm just not going to drive it hard. It's just not worth it to try to get this old duke to be fast. It won't happen, and I've accepted that finally, so I'm done doing stupid stuff like that. But today when I did it, I had a bad shift into second because I was trying to be fast, and the light flickered twice before staying off, and the idle dropped to a little over 500. I pushed in the clutch all the way and put the car into neutral (I was in the middle of nowhere, so I was just testing some stuff with the car) and the idle stayed there. Confused, I stopped the car. Once I stopped, the car came back up to it's regular idle at around 800 and didn't have any other issues for the rest of the drive home. But it's never done that before with the car warm while I'm driving. It usually comes right back up after I lug it down low on accident. Sometimes, if it's cold out and I try to move the car right after starting it, the idle will fall really low after I stop moving for a couple of seconds before steadying out at the normal idle, but it's never done it once the car is warm.
So my questions... is it normal for the check engine light to come on when you have a bad shift like that? I know if comes on when I stall...
What could cause the idle to stay down like that? That's never happened before, and that's what I'm worried about. I can keep the check engine light off by not being stupid, and just shifting smoothly and being easy on the car, but the car usually doesn't drop to a low idle like that unless it's really cold out and I move the car right after starting, in which case, once I stop moving, the idle will drop for a few seconds before steadying out.
The dukes strong point is smooth highway cruising .Trying to get the most acceleration out of it will just see things get broken .As for your CEL problem , it is probably all related to your earlier problem with wiring .But it could be anything , there are a lot of things that will make it come on and off but it is probably a ground wire .A low idle is not a bad thing as long as the car does not stall .
So you think the light is flickering because of a ground issue, and it's happening because of the jerking of the car, not because the engine actually has an issue?
I was just confused, because I put a new distributor cap and rotor, new plugs, and new plug wires in this weekend, and the cars running beautifully. So it scared me when the light started coming on
So to check, should the light come on when I stall? It's always on when you put the car in run, and I guess when you stall, it's essentially in the same position as if the car were to be in the run position while not started, right?
You only need the clutch pedal to engage first gear... Let the synchros handle the rest of the gears... Sure, you can shift faster with the pedal, but at the high cost of excessive clutch wear, as well as flywheel hotspots. I agree with the low idle being likely to cause the check engine light to come on. The sudden, drastic rpm changes probably do, too. Both my 4 and 5 speeds are V6's, but I can shift via synchros faster as I get closer to the redline in each gear. It's the lower rpm's that seem to be slower to shift.
So you're suggesting I shift without the clutch...?
I mean, I know there are transmissions built to be shifted like that, but I don't think this is one of them...
And being that this is my only car, I don't really want to try something new and kill my trans, because you may be able to do it, but with my luck, something will break...
I mean, yeah, it'd save the clutch, but I'd rather replace the clutch than have to rebuild the trans after wearing out my synchros...
So you just... shift it without putting in the clutch? I feel like that'd be even less smooth than my worst days with the clutch.
[This message has been edited by I_N_J (edited 02-14-2016).]
You only need the clutch pedal to engage first gear... Let the synchros handle the rest of the gears... Sure, you can shift faster with the pedal, but at the high cost of excessive clutch wear, as well as flywheel hotspots.
I was driving it around and decided to be stupid and try to give it some gas. NOTE: After this, I'm just not going to drive it hard. It's just not worth it to try to get this old duke to be fast.
There is nothing wrong with putting the pedal to the metal with a duke to get it going. Before I got my current '88 Formula which has taken over the duties, I daily drove and autocrossed my '84 duke (with a swapped in 5-spd) for four years. I ran that car hard at autocross, shifting from 1st to second when the power started to drop off at 4500 RPM or so... and the engine thrived. Of course, the engine needs to be healthy to begin with, and I suspect the engine problems you're experiencing are due to unresolved mechanical issues... not due to you "giving it some gas".
I think my engine is healthy. It's just my fault because I'm not good with the stick yet. I can floor it whenever, and the engine doesn't complain. I just can't shift it smooth AND fast, it's either or, so I put all sorts of strange, jerky loads on the engine when trying to go fast.
But while my engine probably can handle it, I'm just not in a position where I want to find out. It's my only car, so I need to keep it going.
So unless somebody's going to T-bone me or something, I'm gonna try to go easy on her. I mean, even being young, if I had to go somewhere on foot, I wouldn't sprint the whole way. The car probably feels the same way.
I think my engine is healthy. It's just my fault because I'm not good with the stick yet...
No matter how poorly you shift, the end result shouldn't be the following.
quote
Originally posted by I_N_J:
...the idle dropped to a little over 500. I pushed in the clutch all the way and put the car into neutral (I was in the middle of nowhere, so I was just testing some stuff with the car) and the idle stayed there.
The point I was making is that revving the duke high (within reason!) is not going to cause any issues... as long as it is indeed "healthy".
Everything was great for a while... I was just driving smoothly, not pushing it. but then it started flashing the check engine light.
The check engine light would flash on and off at random times.... pretty frequently, too. And whenever the light was showing, the car would lurch forward and decelerate a bit.
The thing is though... I just checked, and it didn't save any codes. It just flashed 12 about a million times before I decided it wasn't going to give me anything more.
So to recap, whenever the check engine light is on, the car decelerates. And the light kinda flashed at random times. Did it 5 or 6 times in the last half mile stretch of road up to my house. It feels like what happens when you take your foot off the gas without pushing in the clutch, how the engine slows down and the car kinda lurches forward. At first it did it when I revved it to 2200, around the final turn to get home... but after that, it just started doing it over and over no matter what the RPM was at.
Then when I parked it in the driveway, the light came on and the engine lugged down to 500 RPM again. It switched off and the engine came back up, but I shut it off then.
What could cause this?
I did put in a new distributor cap, rotor, and spark plugs and wires yesterday, but I don't see how that could cause it. Didn't feel like it was misfiring, and when I actually did have a misfire, the check engine light never came on.
If anyone has any idea what this could be, I'd appreciate it... Like I said, it's my only car...
I'm going to check all the connections tonight. I put dielectric grease on the starter connections after I got them all back together, and I'm thinking that might not have been a good idea...
Now, what exactly could be causing the engine to lose RPMs like that? I mean, the connector may be the root cause, but what is it affecting that's causing the engine to do that? It isn't misfiring, could it be the fuel injector not working?
I'm just raelly confused because it's not tripping any codes. If the light comes on, it should save a code, shouldn't it?
[This message has been edited by I_N_J (edited 02-14-2016).]
If the light comes on, it should save a code, shouldn't it?
No.
Anytime the ignition key is in the "On" position with the engine not running (even momentarily), the light comes on. A code is not saved... otherwise you'd get a code stored every time you turned the key to start your engine.
I agree with Gall about checking potentially loose electrical connections. Could be for the ignition, fuel pump, main power junction, etc.
[This message has been edited by Patrick (edited 02-14-2016).]
I mean, if it comes on while your engine is running....
But I think I know what the issue is.
Code 12 is the diagnostic code, correct?
But it'll also come on while the engine is running IF the ECM is not receiving pulses from the distributor.
That would explain why the code isn't saved, because it's the same code as the diagnostic code.
And I just replaced my cap and rotor yesterday, so it would make sense that there's an issue there.
And come to think of it, the check engine light thing happened twice yesterday, too. Before I did the starter connections, but after I did the distributor cap and rotor.
So tomorrow I need to check the cap and rotor.
Time to pull the old cap and rotor out of the trash....
Does that theory sound like a possibility to you guys?
[This message has been edited by I_N_J (edited 02-14-2016).]
IMO, the CEL flashing on for a split second (if that's indeed what's happening) while the engine is momentarily not running has nothing to do with setting a diagnostic code. It's simply indicating that there's power to the ECM while the key is in the "On" position (and the engine's not running).
[This message has been edited by Patrick (edited 02-14-2016).]
Oh... Forget the non-running thing from the beginning of the topic.
This is a completely different issue.
I'll be driving regularly, the engine will be at like 1800 RPM, and the light will flicker on for a split second, and while that's happening, the car decelerates rather quickly.
As far as the code 12 thing, I'm talking about when it comes on while the car is running. If you put the car in run in diagnostic mode (Jumping the diagnostic terminals), code 12 will flash to say that the car is in diagnostic mode.
Now, IF the diagnostic terminals are NOT being jumped, and the check engine light flashes 12 while the car is running, it means that the ECM is not receiving pulses from the distributor. And that would explain why my car isn't saving the codes. It also makes sense that there's an issue with the distributor, because I just replaced the cap and rotor yesterday.
I'm talking about while I'm driving and the engine is up at like 1800 RPM and the light comes on. Not if it comes on while the engine is lugging really low.
[This message has been edited by I_N_J (edited 02-14-2016).]
Now, IF the diagnostic terminals are NOT being jumped, and the check engine light flashes 12 while the car is running, it means that the ECM is not receiving pulses from the distributor. And that would explain why my car isn't saving the codes. It also makes sense that there's an issue with the distributor, because I just replaced the cap and rotor yesterday.
So you're telling us that while you're driving your Fiero, your CEL is flashing diagnostic code 12? How long does this go on for?
While I'm driving, the check engine light will flash, or rather flicker. It doesn't save any codes though... so even though it doesn't flash long enough for me to see the whole code, I suspect that it's flashing a code 12.
Unless you know of another reason why it wouldn't save the codes...
It also makes sense, because it'll flash code 12 while running if there's a distributor issue. I just replaced my distributor cap and rotor, so that could very well be the issue.
But my thought process is that it will flash a code 12 if you have distributor issues. My issue comes and goes randomly. But it only lasts for a fraction of a second every time it happens. So if somethings wrong, and it only doesn't contact something in the distributor for a fraction of a second, it won't show the whole code, it'll just start.
The big thing that gets it for me though is the fact that when I put it into diagnostic mode in run with the car off, it doesn't show anything other than code 12. If it were any other issue, I should be seeing another code. That and the fact that I just replaced the cap and rotor yesterday, and the issue started happening then. Unless there's some huge coincidence where another issue started happening right then AND my ECM is bad so it doesn't save codes, It just wouldn't make sense to be anything else.
Does that sound correct? Or rather, does that sound like a reasonable theory?
quote
Originally posted by Patrick:
Because maybe there aren't any?
The check engine light comes on. Therefore, the ECM detects something is wrong, meaning it needs to be tripping a code. Unless there's an issue in my dash, but the fact that I can feel something wrong in the engine whenever the light comes on leads me to believe that's not the case.
And I just want you to know, I'm not trying to argue with you here or anything. I just need to figure out what's wrong with my car. I really do appreciate the help.
[This message has been edited by I_N_J (edited 02-14-2016).]
Okay, so what other issues could I be having that cause the check engine light to come on without saving a code? What I don't understand is why the light would come on for no reason.
That and the fact that I know there's an issue with my engine makes it hard for me to believe that the light is just spontaneously coming on without the ECM triggering it.
I'll check my starter connections that I did this morning, but the issue happened before I redid those connections, I just didn't put two and two together and realize there actually was an issue. And I did a damn good job cleaning those connections today, I really don't think I messed them up.
[This message has been edited by I_N_J (edited 02-14-2016).]
What would cause the computer not to store the code? I've checked multiple times, and codes never show up. The only thing I can think of is that it's a code 12, which wouldn't appear to be stored because it's the same as the stock diagnostic code.
If that's not the case though, why else wouldn't the computer store the codes?
The reason I'm so set on this is because it if it were a code 12, that would mean distributor issues, and the distributor could very well be the issue being that I just did work on it.
But if it's not this, why else wouldn't the computer store the codes?
[This message has been edited by I_N_J (edited 02-14-2016).]
CEL flashes and engine faltering are issues I've been dealing with since 1984 on my SE 4 speed. The tach needle will also jump around erratically. It's like the ignition is cutting out erratically and rapidly. The symptoms would diminish under greater acceleration.
For me, it's a signal that the white corrosion deposits on the distributor terminals need cleaning off. Or, replacing the distributor cap and rotor will alleviate the symptoms as well. It typically happens during high humidity or rainy weather. Initially, it goes away when the engine warms up. Clean terminals will keep the symptoms at bay sometimes for a year or more.
Since your cap is new, corrosion isn't the issue, but since the problem didn't happen before you replaced all that stuff, it's a sure bet that something isn't together properly, or something's defective.
Over 32 years, it's never stored a code when the erratic ignition issue is happening. There are many issues that arise that the ECM isn't capable of analysing or setting a code for. You'll likely encounter some!
[This message has been edited by David Hambleton (edited 02-14-2016).]
CEL flashes and engine faltering are issues I've been dealing with since 1984 on my SE 4 speed. The tach needle will also jump around erratically. It's like the ignition is cutting out erratically and rapidly. The symptoms would diminish under greater acceleration.
For me, it's a signal that the white corrosion deposits on the distributor terminals need cleaning off. Or, replacing the distributor cap and rotor will alleviate the symptoms as well. It typically happens during high humidity or rainy weather. Initially, it goes away when the engine warms up. Clean terminals will keep the symptoms at bay sometimes for a year or more.
Since your cap is new, corrosion isn't the issue, but since the problem didn't happen before you replaced all that stuff, it's a sure bet that something isn't together properly, or something's defective.
Over 32 years, it's never stored a code when the erratic ignition issue is happening.
Thankyou! This is perfect! So you had pretty much the exact same issues I'm having, and it was indeed a distributor issue.
Alright, well I was able to get off work tomorrow, so I'll put the old cap and rotor back on and see if the issue persists.
Thankyou! This is perfect! So you had pretty much the exact same issues I'm having, and it was indeed a distributor issue.
Alright, well I was able to get off work tomorrow, so I'll put the old cap and rotor back on and see if the issue persists.
I've had similar issues on my Formula 5 speed ('88 2.8L). The first time it began to run very poorly on a highway, I found the distributor interior was so rusty I don't know how it ever ran at all. A new distributor was installed. The second time, it just wouldn't start. I opened it up, cleaned everything, put new ICM heat sink paste in and haven't had a problem since (about 8 months).
The '84 SE quit while driving and wouldn't restart despite it showing spark & fuel. I swapped in a spare ECM from my '86 & was back in business.
None of these incidents produced codes. In this era of self-diagnosing cars, Fieros frequently aren't.
code 12 does not mean distributor issues. Code 12 means the ECM is hooked up and working. Every Fiero with no mechanical issues will flash a 12
Code 12 while in run and in diagnosis mode means the ECM is hooked up and working. Code 12 while the engine is on not in diagnostic mode means the ECM isn't getting pulses from the distributor.
"Diagnostic Mode Active (ECM OK) When the diagnostics terminal is grounded, the ignition turned on and the engine is not running, the ECM will flash Code 12 three times. If it's flashing this code while the engine is running (Field Service Mode), then the ECM is not receiving any pulses from the distributor."
[This message has been edited by I_N_J (edited 02-14-2016).]
Originally posted by I_N_J: "Diagnostic Mode Active (ECM OK) When the diagnostics terminal is grounded, the ignition turned on and the engine is not running, the ECM will flash Code 12 three times. If it's flashing this code while the engine is running (Field Service Mode), then the ECM is not receiving any pulses from the distributor."
Is your car doing that? Or is it flashing the light randomly?
Shifting without the clutch pedals is a timing game. Not a hard one to learn, either. You're in first gear. You accelerate to, say, 3500 rpm. You let off the gas at the same time as pulling the shift knob out of first gear and aim for second. When the RPM's drop, you'll hit a sweet spot where the revs now match what they should be in second gear at your current speed. The synchros allow the shifter to be fully pressed into second gear without much extra effort. If you do this successfully, you'll feel the shifter gently pop into place. If you miss, you'll feel the shifter rattle pretty rough. I drive all 3 of my manual transmission cars this way and have yet to experience any negative effect on my transmissions. I'm not clear on how this is bad advice, and I'm more than willing to listen to why I may be wrong. This is what synchros are intended for, and when done properly, shouldn't be harmful. This method can delay your shift time very slightly, but it IS a smooth transition when done right. In my opinion, using the clutch pedal with every shift promotes more wear and is also rougher on the tranny, especially if the shifts are causing engagement with dramatic difference between tranny and engine speed. Just like dumping the clutch to do a burnout, to some effect.
Is your car doing that? Or is it flashing the light randomly?
The light is flickering. Every once in a while, the light will flicker on and off really quickly.
It isn't going all out and giving me a code 12, but being that there are no saved codes and all I see is the 12 diagnostic code, and being that I just put on a new cap and rotor yesterday, and this issue happened for the first time yesterday, it makes sense that the problem is there.
What do you think? Does my thought process make sense?
quote
Originally posted by viperine:
Shifting without the clutch pedals is a timing game. Not a hard one to learn, either. You're in first gear. You accelerate to, say, 3500 rpm. You let off the gas at the same time as pulling the shift knob out of first gear and aim for second. When the RPM's drop, you'll hit a sweet spot where the revs now match what they should be in second gear at your current speed. The synchros allow the shifter to be fully pressed into second gear without much extra effort. If you do this successfully, you'll feel the shifter gently pop into place. If you miss, you'll feel the shifter rattle pretty rough. I drive all 3 of my manual transmission cars this way and have yet to experience any negative effect on my transmissions. I'm not clear on how this is bad advice, and I'm more than willing to listen to why I may be wrong. This is what synchros are intended for, and when done properly, shouldn't be harmful. This method can delay your shift time very slightly, but it IS a smooth transition when done right. In my opinion, using the clutch pedal with every shift promotes more wear and is also rougher on the tranny, especially if the shifts are causing engagement with dramatic difference between tranny and engine speed. Just like dumping the clutch to do a burnout, to some effect.
Yeah, I'm sure it can be done. But I'm also sure I'd be terrible at it... I mean, it'd be great to learn in case my clutch line goes out someday, but daily driving like that,I'd kill my synchros in no time. And it's easier to put in a clutch than to rebuild a transmission.
First, I believe it's ill advised to be suggesting to someone who admits to having trouble driving a stick-shift even while using a clutch... to try shifting without a clutch. Recipe for disaster, IMO.
Secondly, I can't believe that shifting without using a clutch is easier on a tranny than using a clutch. No way you can convince me of that. And yes, I have the ability to shift without using the clutch... but choose not to do so.
Patrick, I can certainly see your concerns, and they are valid. My stance in shifting is that rev-matching is the healthiest way to use a manual, and that synchro shifting more or less forces you to learn those points. You can reasonably rev-match with a clutch pedal as well, but for someone who hasn't come to know their individual car well yet, they can easily wear everything out much faster. The only drawback is that it may take someone new longer to learn how to engage first without so much slippage.
Originally posted by I_N_J: The light is flickering. Every once in a while, the light will flicker on and off really quickly.
It isn't going all out and giving me a code 12, but being that there are no saved codes and all I see is the 12 diagnostic code, and being that I just put on a new cap and rotor yesterday, and this issue happened for the first time yesterday, it makes sense that the problem is there.
What do you think? Does my thought process make sense?
No....
You would see a very distinct code 12. The flickering is something else.
New parts are not necessarily good parts... and make sure the rotor is seated... check the button in the inside top of the cap for a spring. sometimes they are missing.
You can reasonably rev-match with a clutch pedal as well...
That's what I do. I usually have the revs in the ballpark before I release the clutch, while both up and down shifting.
The theory behind rev-matching is sound, but asking a relatively inexperienced stick-shift driver to try it without using a clutch is... risky at best.
[This message has been edited by Patrick (edited 02-14-2016).]
You would see a very distinct code 12. The flickering is something else.
New parts are not necessarily good parts... and make sure the rotor is seated... check the button in the inside top of the cap for a spring. sometimes they are missing.
Tomorrow I'm planning on taking off the new cap and rotor and checking them out, then throwing on the old cap and rotor. If my issue is fixed, great. If not.... I don't even know what to do then...
If this isn't it, I don't know what else could be it. Any other code should be saved.
And I mean, I replaced my cap and rotor, and on the test drive I took it for afterwards, it did the check engine thing for the first time. I didn't think it was really an issue, I thought it had to do with my shifting, which is why I started this topic in the first place. So being that it happened right after I replaced the rotor and cap, it should be this, right?
God I hope this is it... if this isn't the issue... I don't even know where to start
Originally posted by I_N_J:I did put in a new distributor cap, rotor, and spark plugs and wires yesterday, but I don't see how that could cause it....
If I were you: I'd first check that all the wires are firmly and properly seated on the plugs & into the distributor cap. Then I'd make sure the rotor is properly seated and that it hasn't been nicking the distributor cap terminals. Then I'd make sure the cap is seated and fastened properly. Then I'd try the old cap & rotor. Then I'd try each old spark plug wire, one at a time. Then I'd try each old spark plug, one at a time. (Did you install AC Delco plugs? Did you check the gap?)
I think if you try one thing at a time, you may well isolate the source of the issue.
[This message has been edited by David Hambleton (edited 02-14-2016).]
