Mechanics

WIERD IDLE, DIESELING, POOR GAS MILEAGE.

1991 Acura Integra

Engine Performance problem
1991 Acura Integra 4 cyl Front Wheel Drive Manual 220000 miles

I bought the car with no airbox, 02 sensor, or muffler. The exhaust smelled of unburned fuel and the idle was low rough and choppy, the ECU was showing codes1 and 43. I have put a new intake pipe and filter and put in an O2 sensor. The idle has gotten a little better and so has the performance, the code 1 is gone.

I still have a code 43, rough idle when the engine is cold. When the engine is warm it does one of these two things

1. surges to about 1700RPM then drops to about 1100RPM, repeat... etc

2. Idles high at about 1700RPM until a CEL comes on and drops dow to about 11-1200RPM and holds steady.

The car has also started dieseling when I shut off the engine.

Here are links to videos that show the idle when cold and the idle surging

http://s301.photobucket.com/albums/nn58/tristanboyd/?action=view&current=1104090951-00.flv

http://s301.photobucket.com/albums/nn58/tristanboyd/?action=view&current=1103091653-00.flv


:::EDIT::: Since this post I have taken apart, cleaned, and reinstalled the FITV and the surging has gotten just a little better... other syptoms still exist, crappy quality idle, etc.
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Tristanb
November 4, 2009.




That is a bad idle. Have you checked timing? Knock sensor? Vacuum leaks? TPS / MAF sensor? EGR? It's acting like either the timing is out or there is a problem with the throttle position sensor.

Let me know.

I've checked for vacuum leaks and have even replaced a few lines, it looks like the previous owner did the same. I did bump the timing a little to see if it would help, and it did but only a little. I'll get a little more accurate on the timing when I get my hands on my timing gun tomorrow. I don't think this car has a knock sensor, I could be wrong, I can't seem to find anything in my chiltons about it and think, not sure but think that the integras with the b18a1 engines didn't have a knock sensor.

I know how to test TPS on a GM vehicle but not a honda.

Tiny
Tristanb
Nov 4, 2009.
Let me know what you find when you get the timing light.

I will do that.

Btw: I just took off the IAC and cleaned it out and reinstalled it, a little improvement but not much. Its still missing and stuff but a little better.

I cleaned the FITV and IAC as per a ton of right ups on several forums about some of the same issues. Again it helped a little but hasn't solved the problem, I'll reply when I get the timing to specs tomorrow.

Tiny
Tristanb
Nov 4, 2009.
I checked the timing as per my Chilton's and I could not see the timing marks on the crankshaft pulley at all, so I put it where it sounded best and then backed it off a tad. I rechecked for vacuum leaks and could not find any and I fixed a few spots that one could question. The worst part is the missing until it heats up to full operating temp. A few people on the forums are have suggested the distributor if cleaning those parts didn't do it, but the distributor is brand new. I didn't throw any codes today. Any ideas?

Tiny
Tristanb
Nov 5, 2009.
Well it's good that it didn't give any codes today. You may need to get down under the car and check the crank for timing marks. I always draw a white line on it with chalk so I can see it better.

As far as the idle, did I mention checking the EGR? Also, one way to check for a vacuum leak (I don't like doing it) is spraying starting fluid around the hoses. If there is a leak, the engine will suck in the starting fluid and the RPM's will increase. I hate doing it because if you hit a spot on the engine that is hot enough, it can catch fire. If you want to try it, make sure you have a fire extinguisher near by.
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Thats how I did it except I used carb cleaner and listened for a drop in RPM, I'm very weary about the starting fluid for the same reason you said plus I know that stuff can be very dangerous to an engine if it sucks up too much. When I go on lunch tomorrow I'll check again for timings marks, it'll be daylight so maybe I can at least find the grooves and mark them like you said. I know the EGR can cause crappy mileage but can it cause missing too? I've had my ups and downs with EGR on the Fiero's I used to have. I'll try to get some more video of how the cold idle is now so we have something to compare progress to.

Tiny
Tristanb
Nov 5, 2009.
I'll be waiting.

Cold idle this morning. This is the first time it has actually died during cold idle

Tiny
Tristanb
Nov 6, 2009.
When you rev it, it sounds good. Listening to it, it sounds like a timing issue. I can't remember if I asked you to check the EGR. The valve could be stuck causing a problem.


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