HELP - AGAIN - Very SLIGHT hesitation while driving - itermitent check engine light
ammcf1
10-06-2007, 08:42 AM
One thing leads to another (it seems)...
1994 Metro - 3-cyl - automatic, 103,000 miles. New fuel filter, new timing belt, new water pump, new cap, rotor, and plugs.
A few days ago (after I got the timing belt replaced) I noticed the car beginning to SLIGHTLY hesitate for about a half-second from time to time. It happens periodically (as often as every 5 seconds or so sometimes). It also happens as I am driving at anything from highway speeds all the way down to neighborhood speeds, but I don't notice it at idle. I would describe it as a very slight "hiccup" of sorts. It's so slight I didn't even notice it at first - nothing at all like a back-fire. It's worse when pulling any kind of load (people in the car, up a hill or mountain, etc.)
Maybe related, maybe not - about 2 days after I first noticed the hiccup, the check engine light came on and stayed on for the next 75 driving miles (or so) and then went out. I don't have a Checker or Kragen that has the ability to check the code nearby (small town). I may take it to my neighborhood mechanic to see if he will run the code for me for free - but the light is now off.
Any ideas? Suggestions? Help? Snide remarks?
1994 Metro - 3-cyl - automatic, 103,000 miles. New fuel filter, new timing belt, new water pump, new cap, rotor, and plugs.
A few days ago (after I got the timing belt replaced) I noticed the car beginning to SLIGHTLY hesitate for about a half-second from time to time. It happens periodically (as often as every 5 seconds or so sometimes). It also happens as I am driving at anything from highway speeds all the way down to neighborhood speeds, but I don't notice it at idle. I would describe it as a very slight "hiccup" of sorts. It's so slight I didn't even notice it at first - nothing at all like a back-fire. It's worse when pulling any kind of load (people in the car, up a hill or mountain, etc.)
Maybe related, maybe not - about 2 days after I first noticed the hiccup, the check engine light came on and stayed on for the next 75 driving miles (or so) and then went out. I don't have a Checker or Kragen that has the ability to check the code nearby (small town). I may take it to my neighborhood mechanic to see if he will run the code for me for free - but the light is now off.
Any ideas? Suggestions? Help? Snide remarks?
91Caprice9c1
10-06-2007, 04:55 PM
You can check the Diatnostic Trouble Code (Check Engine Light) yourself. Have a peek under the driver side dash at the fuse panel. You will notice that one of the slots is raised off the panel a bit - it has some built up plastic around it - located toward the firewall on the panel if I remember correct. Stick a fuse in raised fuse holder, sit in the driver seat, turn the ignition on and count the CEL flashes.
Blink-pause-Blink-Blink = 12
Blink-Blink-pause-Blink = 21
Blink-pause-Blink-Blink--long pause--Blink-Blink-pause-Blink = 12 and 21
When all the DTC's have been displayed it will repeat them.
Have you checked ignition timing?
It may be possible the guy R&Ring your timing belt got it off a little.
Have you checked fuel pressure?
Everything plugged in under the hood?
-MechanicMatt
Blink-pause-Blink-Blink = 12
Blink-Blink-pause-Blink = 21
Blink-pause-Blink-Blink--long pause--Blink-Blink-pause-Blink = 12 and 21
When all the DTC's have been displayed it will repeat them.
Have you checked ignition timing?
It may be possible the guy R&Ring your timing belt got it off a little.
Have you checked fuel pressure?
Everything plugged in under the hood?
-MechanicMatt
ammcf1
10-06-2007, 05:48 PM
Thanks MechanicMatt, I'll try the code thing... but I have some questions related to the other things you said...
Once I get those codes... how do I know what they mean?
How do I know if the timing best IS on correctly or not?
How do I go about checking the engine timing? I don't have many diagnostic tools...
How do I check the fuel pressure? same problem...
Thanks...
Once I get those codes... how do I know what they mean?
How do I know if the timing best IS on correctly or not?
How do I go about checking the engine timing? I don't have many diagnostic tools...
How do I check the fuel pressure? same problem...
Thanks...
ammcf1
10-06-2007, 06:10 PM
I haven't checked the codes yet, but I did notice that it is doing the same "hiccup" thing very slightly when it is in idle. I also notice a periodic "click" that corresponds with each time it hiccups. The click sound seems to be coming from somewhere behind and below the air cleaner - I can't isolate it very well. Does that give any ideas?
91Caprice9c1
10-07-2007, 08:14 AM
I haven't checked the codes yet, but I did notice that it is doing the same "hiccup" thing very slightly when it is in idle. I also notice a periodic "click" that corresponds with each time it hiccups. The click sound seems to be coming from somewhere behind and below the air cleaner - I can't isolate it very well. Does that give any ideas?
http://www.troublecodes.net/GMimport/
This will give you relevant codes. I forgot to mention that each code will repeat itself three times before going onto the next code.
http://www.automotiveforums.com/vbulletin/showthread.php?t=756903
See this thread about checking fuel pressure.
Behind and below the air cleaner is interesting. That is precisely where all the sensor grounds are located - a bad connection here will definitely cause performance ailments. I dont know if there is enough power to cause an arc large enough to produce an audible click, but its worth checking out. Remove your air cleaner and housing. It will take some looking/feeling but eventually you will find a bundle of wires bolted to the back of the intake manifold with a 10mm (hex-head) bolt. These are your senor grounds. Take this bolt out, be sure the connection is clean and tight so that we can rule this out.
You will need a timing light to check the timing, and a paper clip you dont mind bending out of shape. Unfortunately to check to see if the belt was installed correctly you have to take a bunch of stuff off, but if your ignition timing is spot on, it may be safe to assume the belt was installed correctly.
-MechanicMatt
http://www.troublecodes.net/GMimport/
This will give you relevant codes. I forgot to mention that each code will repeat itself three times before going onto the next code.
http://www.automotiveforums.com/vbulletin/showthread.php?t=756903
See this thread about checking fuel pressure.
Behind and below the air cleaner is interesting. That is precisely where all the sensor grounds are located - a bad connection here will definitely cause performance ailments. I dont know if there is enough power to cause an arc large enough to produce an audible click, but its worth checking out. Remove your air cleaner and housing. It will take some looking/feeling but eventually you will find a bundle of wires bolted to the back of the intake manifold with a 10mm (hex-head) bolt. These are your senor grounds. Take this bolt out, be sure the connection is clean and tight so that we can rule this out.
You will need a timing light to check the timing, and a paper clip you dont mind bending out of shape. Unfortunately to check to see if the belt was installed correctly you have to take a bunch of stuff off, but if your ignition timing is spot on, it may be safe to assume the belt was installed correctly.
-MechanicMatt
ammcf1
10-07-2007, 09:36 AM
OK, the wires are clean and firmly connected - and I still hear the clicking sound periodically. Also, the hiccup is becoming more distinct - I can hear it through the exhaust pipe and also with the hood up. Through the exhaust it sounds somewhat similar to a backfire, but with no "bang" and not as obvious of a hesitation. I checked the plugs thinking they might be fouled, but they are fine.
91Caprice9c1
10-08-2007, 05:19 AM
New fuel filter, new timing belt, new water pump, new cap, rotor, and plugs.
Did you replace the spark plug WIRES along with these items?
Did you replace the spark plug WIRES along with these items?
ammcf1
10-08-2007, 09:03 AM
Hey 91Caprice... DUH!!! Living in a small town I just took what they had on hand when I did the plugs, cap, roter, etc., which didn't include the wires - I didn't want to have to wait to do the work. BUT, I probably should have in retrospect. I'll get those ordered today
BUT there's more to the puzzle now...
I drive every day in the early morning hours and it's doing MORE really weird things now.
1. Needless to say, the hesitation/hiccup is getting worse the more I drive it - very noticeable and beginning to impact acceleration, especially when taking hills. This morning it actually died once when I was coming to a stop because of it. Hopefully the spark plug wires are the remedy for that.
2. The temperature is moving to 3/4 of the way up the gauge within 2 minutes of starting the vehicle. It used to take up to 25 minutes to get even 1/2 the way up the gauge. Then as I'm driving, it will periodically go right up to the white line just below the red "warning" area - usually when I slow down or drive more slowly. When I speed up (highway speeds) it will cool off, from airflow I assume. This morning I stopped under a streetlight to check it and the reserve coolant was totally empty, so I refilled it. After that the temp did not go AS high, but still seemed on the high end.
3. I suddenly have a squeeking belt too. It happens at slower speeds, eventually disappearing as my speed gets to about 40 or 45 mph. I'm assuming that it's the alternator belt because the lights are dimmer when the squeeking is going on - and when it stops, they illuminate more fully.
Any OTHER suggestions?
Overall, though I have a gut feel there are probably some pretty simple solutions to all this, it's beginning to feel like this car is gasping for it's final breath! I hope not, I really can't afford that and NEED this kind of ecomomical car!
BUT there's more to the puzzle now...
I drive every day in the early morning hours and it's doing MORE really weird things now.
1. Needless to say, the hesitation/hiccup is getting worse the more I drive it - very noticeable and beginning to impact acceleration, especially when taking hills. This morning it actually died once when I was coming to a stop because of it. Hopefully the spark plug wires are the remedy for that.
2. The temperature is moving to 3/4 of the way up the gauge within 2 minutes of starting the vehicle. It used to take up to 25 minutes to get even 1/2 the way up the gauge. Then as I'm driving, it will periodically go right up to the white line just below the red "warning" area - usually when I slow down or drive more slowly. When I speed up (highway speeds) it will cool off, from airflow I assume. This morning I stopped under a streetlight to check it and the reserve coolant was totally empty, so I refilled it. After that the temp did not go AS high, but still seemed on the high end.
3. I suddenly have a squeeking belt too. It happens at slower speeds, eventually disappearing as my speed gets to about 40 or 45 mph. I'm assuming that it's the alternator belt because the lights are dimmer when the squeeking is going on - and when it stops, they illuminate more fully.
Any OTHER suggestions?
Overall, though I have a gut feel there are probably some pretty simple solutions to all this, it's beginning to feel like this car is gasping for it's final breath! I hope not, I really can't afford that and NEED this kind of ecomomical car!
ammcf1
10-08-2007, 05:18 PM
:grinyes: It's healed! MechanicMatt, you were right - the spark plug wires seem to have been the culprit. I wasn't patient enough to find out which one, and I didn't really care.
On the temperature fluctuations from last post - I'm curious if my "theory" holds water. I'm suspecting that the engine was getting overly hot because the pistons that were firing correctly were working overtime to keep up with the driving demand?
On the squeeky belt... is there anything that can be done for that?
Thanks for all your help!
On the temperature fluctuations from last post - I'm curious if my "theory" holds water. I'm suspecting that the engine was getting overly hot because the pistons that were firing correctly were working overtime to keep up with the driving demand?
On the squeeky belt... is there anything that can be done for that?
Thanks for all your help!
91Caprice9c1
10-08-2007, 05:19 PM
1. Needless to say, the hesitation/hiccup is getting worse the more I drive it - very noticeable and beginning to impact acceleration, especially when taking hills. This morning it actually died once when I was coming to a stop because of it. Hopefully the spark plug wires are the remedy for that.
Alright. Check to see that the two screws that affix the TPS to the Throttle body are tight. A TPS out of adjustment will degenerate driveability and may cause a wandering/rough idle. TPS is circled below.
http://swift.crime.one.pl/img/artykuly/kody_bledow/przepustnica.jpg
Replace those spark plug wires (may not fix the problem, but certainly couldn't hurt - bad wires do cause poor driveability and are the weak link in the secondary ignition system).
Now - another thing to check - the coolant temp sensor in the throttle body. Arrow "A" below.
http://swift.crime.one.pl/img/artykuly/kody_bledow/czujniki.jpg
I have a '94 geo metro 3cyl automatic just like yours that had clogged coolant passages leading to this sensor causing hesitation and a rough idle. UNPLUG this sensor and see if it clears things up at all. Thats how I figured it out. As soon as this sensor was disconnected, the car woke up - maybe you'll have similar luck.
2. The temperature is moving to 3/4 of the way up the gauge within 2 minutes of starting the vehicle. It used to take up to 25 minutes to get even 1/2 the way up the gauge. Then as I'm driving, it will periodically go right up to the white line just below the red "warning" area - usually when I slow down or drive more slowly. When I speed up (highway speeds) it will cool off, from airflow I assume. This morning I stopped under a streetlight to check it and the reserve coolant was totally empty, so I refilled it. After that the temp did not go AS high, but still seemed on the high end.
3. I suddenly have a squeeking belt too. It happens at slower speeds, eventually disappearing as my speed gets to about 40 or 45 mph. I'm assuming that it's the alternator belt because the lights are dimmer when the squeeking is going on - and when it stops, they illuminate more fully.
I think these two are related, slipping alternator/watpump belt. Tighten that bad boy up and this should keep the coolant circulating and the alternator turning.
It should not take half an hour to reach almost operating temperature. Replace your thermostat or replace the one that is missing.
Coolant may have spewed out of the reservoir as a result of getting quite hot, and then after some cooling(?) sucked the excess in the reservoir back into the system - how was the level in the radiator? If after tightening the Alternator belt, you are still losing coolant, replace the radiator cap and keep an eye out for leaks.
-MechanicMatt
Alright. Check to see that the two screws that affix the TPS to the Throttle body are tight. A TPS out of adjustment will degenerate driveability and may cause a wandering/rough idle. TPS is circled below.
http://swift.crime.one.pl/img/artykuly/kody_bledow/przepustnica.jpg
Replace those spark plug wires (may not fix the problem, but certainly couldn't hurt - bad wires do cause poor driveability and are the weak link in the secondary ignition system).
Now - another thing to check - the coolant temp sensor in the throttle body. Arrow "A" below.
http://swift.crime.one.pl/img/artykuly/kody_bledow/czujniki.jpg
I have a '94 geo metro 3cyl automatic just like yours that had clogged coolant passages leading to this sensor causing hesitation and a rough idle. UNPLUG this sensor and see if it clears things up at all. Thats how I figured it out. As soon as this sensor was disconnected, the car woke up - maybe you'll have similar luck.
2. The temperature is moving to 3/4 of the way up the gauge within 2 minutes of starting the vehicle. It used to take up to 25 minutes to get even 1/2 the way up the gauge. Then as I'm driving, it will periodically go right up to the white line just below the red "warning" area - usually when I slow down or drive more slowly. When I speed up (highway speeds) it will cool off, from airflow I assume. This morning I stopped under a streetlight to check it and the reserve coolant was totally empty, so I refilled it. After that the temp did not go AS high, but still seemed on the high end.
3. I suddenly have a squeeking belt too. It happens at slower speeds, eventually disappearing as my speed gets to about 40 or 45 mph. I'm assuming that it's the alternator belt because the lights are dimmer when the squeeking is going on - and when it stops, they illuminate more fully.
I think these two are related, slipping alternator/watpump belt. Tighten that bad boy up and this should keep the coolant circulating and the alternator turning.
It should not take half an hour to reach almost operating temperature. Replace your thermostat or replace the one that is missing.
Coolant may have spewed out of the reservoir as a result of getting quite hot, and then after some cooling(?) sucked the excess in the reservoir back into the system - how was the level in the radiator? If after tightening the Alternator belt, you are still losing coolant, replace the radiator cap and keep an eye out for leaks.
-MechanicMatt
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