2003 Honda Civic, 1.7L, standard, 144K, no service records. The first symptom was bad gas mileage, although that isn't proved. Then it started missing and stalling.
The only codes are for misfire on 1,2 and 4 and multiple misfires. I pulled spark plug 1 ( since the engine is backward it was probably was 4 ) and it seemed fine, not wet, good spark.
This happened before but it turned out to be bad gas. I thought that at first but fuel treatments haven’t improved anything. I haven't found the fuel rail yet to take pressure measurements.
I don't have much time or energy so if I am asking where to look next. The fuel filter is in the gas tank. I am thinking timing belt. It looks like a while to get the cover off and I don't see any inspection plugs. I think I have to remove the valve cover also.
I remember hondas around that vintage having issues with the egr ports plugging up causing symptoms similar to what youre describing.
It misses at all speeds, it doesn't sound like the EGR.
I got the screws holding the belt cover off and after lifting up the valve cover I see the timing belt is loose. That has to be the problem. It is obvious my skills in Honda are severely lacking. I have not figured out how to get either covers off yet.
Has anyone done one of these timing belts? I have not been able to get the service manual for this car.
What makes you think it is the timing belt? You generally won't see misfires with a timing belt.
Spark plug "seemed fine". What was the gap?
My sister in law had that happen in a 2003 Civic. The car felt sluggish and would get really hot.
New belt and tensioner cured it.
I dont remember much but it was a very easy timing belt job. I did it in a few hours and it was very intuitive.
Just support the engine from underneath and remove the side motor mount. I bet there is a 10mm bolt underneath.
You have to loosen and move a bunch of stuff to get to the timing belt covers. It’s more of a pain then difficult. Before you get too far, make sure you can get the crank pulley bolt loose.
Before all that, are you sure you don’t have a bad coil(s)?
The belt is so loose I can push it in an inch easily. I swapped coils with the only one not missing and there was no change. Because the engine rotates counter clockwise I can't use the starter to loosen it like I did with the pilot. I think it jumped a tooth so I better check the valves with a boroscope. Then tow it out to be repaired if I can't find a manual.
If it runs at all, the valves are fine.
I'm still skeptical that it jumped a tooth, usually if it even runs at all like that, it's so pig rich that the plugs will be fouled, on a speed-density EFI car. And it won't merely be "poor MPG" but it will feel like it has about 30hp.
Bad converter??
Wait is this the vtec motor? If the vtec solenoid is bad/ stuck will it cause similar issues?
If the belt is loose, change it.
Once you know that is correct, and the car still shows symptoms then start from there knowing the belt doesnt have that much slack.
It literally should not take you more than an hour to get the covers off and assess the situation.
I started this thread 3 weeks ago to try to get help of where to start the diagnose. I only checked the timing belt when I couldn't find anything else wrong. My next step was going to be to scope the EGR system. It took me an hour to get the 3 top cover bolts out, and another to get the valve cover up enough to release the top cover. Neither cover is off yet because of the wires that are everywhere. This car is a nightmare.
Yes this is a Vtec. I forgot that part in the description. I will look at the solenoid after the belt is fixed.
The engine misses so bad it shakes. The plugs are perfect. I thought they would be wet after a short run but they are dry. It has no power and stalls under high load. I have to assume that the variable valve timing is screwed up by the timing changes caused by the bad tensioner. If that is not the case I will have to start the process all over again when I get it fixed.
If or when I get the timing belt fixed I will start a new thread if it still runs the same.
In reply to pjbgravely :
If the plugs aren't wet and it's misfiring horribly, I'd want to know what fuel pressure is. Especially if it has no power and stalls under high load.
I'm not doubting that, at 144k, it needs a timing belt, especially if it's a bit flappy. But generally, if the timing is off, a speed-density system will be running pig-rich since the manifold vacuum will be low for a given amount of airflow, so the computer will be heavily overfueling.
I will edit this with an image after I boot up my work tablet.
Okay, here we are editing. This is a screencap of why my job sucks sometimes. This was taken shortly before closing on the Friday before a four day weekend. Had to tell someone that they weren't going to drive six hours each way to visit their family over the holiday. What this IS, is a scope trace of the current drawn by the fuel pump, or a vehicle that had almost exactly the same symptoms as yours. There's supposed to be a nice sawtooth pattern there as the eight or ten divisions on the commutator (usually eight, sometimes ten, rarely six) draw current. You can see a regular pattern here, but the pattern is not that of a good fuel pump, it's one of a pump that was dying. I didn't need to check fuel pressure at this point. It took less time to find the fuel pump fuse, replace it with a loop of wire, and amp-clamp it and watch it on the 'scope.
I'm not saying that you NEED a 2 channel scope to diagnose your car. But I am saying that everything you are telling me is that, if your car was towed in to my shop, the very first thing I would investigate is fuel pressure, either by direct measurement or by observing fuel trims and scoping the fuel pump's current pattern.
It was driven to my garage. I test drove it and it missed exactly the same at idle and at full throttle. I thought it was a fuel pressure problem but I lost my pressure tester. I went to change the fuel filter but I found out it was in the gas tank.
The only suggestion I got here was to look at the EGR. The Internet was telling me to look at the timing belt so I started there after checking all the basics. The belt looks changed, I believe the tensioner is shot. My Honda Pilot had an advance auto tensioner die in 5K. I have to fix that first and continue on if that doesn't fix it.
The timing belt is finally fixed. The easiest part was the crank bolt, a 3/4 impact gun and a 1/2 air hose make it spin off like nothing. The 1/2 impact couldn't budge it. The belt was changed but the tensioner went bad. Honda says their tensioners are good for 2 belts cycles, they were wrong. It did not jump a tooth.
It still misses but runs much better. The scanner said it was only missing on cylinder 2 now. I swapped coils with no change. I changed spark plugs, no change. I unplugged the #2 injector, and there was no changed. I can't find any numbers but the other injectors read 9-10 ohms and #2 reads 25. I have to decide whether or not to replace them all. I checked fuel pressure and it is a steady 45 lbs. Again I haven't found what it should be yet. I found a manual that says 25 lbs but it says CNG in the title so I don't think it is the right one.
My compression tester is too short but I am not sure I need to do it. the engine has 150K. I am thinking the injector is the smoking gun.
Can you change out that injector and confirm the problem moves with the injector?
I took it out and it now reads 85 ohms, it is bad for sure. All I need to decide is whether to buy 1 or 4.
Can you junk yard an injector? Always a chance you'll get a bad one but you're most likely to get a good one and at that point you can confirm that a good injector fixes it and decide where to go from there.
dj06482 said:
Can you change out that injector and confirm the problem moves with the injector?
I tried your idea, I switched 1 and 2 thinking they were far way on the firing order. When it started it was missing. There were no codes during the entire run. It then started to run perfectly. It started to miss again so I unplugged injector 1. There was no changed. I unplugged 2 and the engine stalled. I think the injector is leaking but not working otherwise. That is the only way I can see it would run so well on 3 cylinders. The test showed that cylinder 2 is good, there are no compression or PCM problems and all I need are injectors. I ordered 4 from rock auto. Now to work on the water leaks into the cabin
I got 4 new injectors and and started it up. It missed worse than before. I used a stethoscope and found #4 injector was bad. I put the old one back in and it ran fine. Of course all the injector plugs broke the last time I removed them.
I just replaced the injector, the connectors and fixed the leaking valve cover gasket and got the nightmare out of the garage.
