my engine seems to be hesitating and misfiring when im just cruising at about 3000-3500 rpm, but it doesn't when i'm on it hard. also when i swapped in my motor i had the exhaust manifold off and the exhaust ports where absolutely caked with carbon build-up. seems like it might be some kind of fuel mix problem, but i don't know. the engine is not throwing any codes.

 

Things to check

Spark plugs, see how they look
Spark plug wires
Cap
rotor
Fuel Filter

Have you had any problems with your brakes lately ? Take the vacuum hose of your brake booster, stick your finger in there. If its wet that could be your problem. Check the other things first and see how they look.




Modified by 90blackcrx at 5:33 PM 9/29/2003

 

i had a similar problem with one of my swaps...it turned out to be a clogged fuel filter...

 

Try checking your fuel filter, like the other guy suggested, and also check your ignition components, especially the notorious Honda igniter.

 

any check engine lights? does the computer flash any codes mine does

comes out to be air control meter/valve

 

spark plugs are new, wires are new, i will check the fuel filter. any suggestions on how to get my whole system cleaned out. like i said before, when i took off my exhaust manifold there was some serious carbon build-up, also any chance my timing not being adjusted to perfection may cause misfiring at only 3-3.5k rpm? i only eyed up the timing instead of using a light to do it perfectly.
thanks for the help

 

i had a friend that when he reached 3 grand he lost all of his power pretty much seems like a similar thing.... ended up his shaft in his distributor was bent a lil bit and was giving him the problem i have no clue how the hell his shaft got bent but hell itz worth a check man... peace

 

My B16 would run like a banshi when I stomped on the gas, but at steady state cruse it would sputter and stumble. It also ran a little hot. At steady state the ECU is reading what is going on with the engine. It uses the O2 sensors to monitor the air fuel mixture. At wide open throttle the ECU defaults to a preset program. I would recommend un-plugging the O2 sensors. When you do this the ECU defaults to a rich mode. If the hesitation goes away and it runs great then it is your O2 sensors. You then make a trip to Auto Zone, pick up some Bosch universal for about $17 bucks and have a He?? of a time installing them into your header.
If the stumble does not go away. Look at what the other guys recommended.
Good luck

 

thats what the car does, runs great at full throttle, but when just cruising its sputtering at 3k, ive already replaced one o2 sensor so mabe ill try the other one. the manual also says its probably my iac valve or my map sensor, thoughts? comments? thanks for all the help kids
completely off topic, i also need myself some new suspension badly, my car handles like a pig in sh*t. ive got about 450 bucks to spend on shocks and springs all around, any one have any suggestions around that price range?

 

The best way to tell if it is the O2's is just to unplug them. If the stumble goes away then you know that was the problem and you can replace it/them.

 

cap and rotor

replace em when you do the swap, or they'll go bad soon enough

 

Maybe try switching your o2's. one monitors cyl 1+4 and the other 2+3. If your ecu is reading the wrong ratios, one will run richer and the other leaner. It's happened to a lot of people.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hughesl &raquo;</TD></TR><TR><TD CLASS="quote">My B16 would run like a banshi when I stomped on the gas, but at steady state cruse it would sputter and stumble. It also ran a little hot. At steady state the ECU is reading what is going on with the engine. It uses the O2 sensors to monitor the air fuel mixture. At wide open throttle the ECU defaults to a preset program. I would recommend un-plugging the O2 sensors. When you do this the ECU defaults to a rich mode. If the hesitation goes away and it runs great then it is your O2 sensors. You then make a trip to Auto Zone, pick up some Bosch universal for about $17 bucks and have a He?? of a time installing them into your header.
If the stumble does not go away. Look at what the other guys recommended.
Good luck </TD></TR></TABLE>


Holy ****, I thought I was the only one. My b16 has been doing the same exact thing, under partial throttle it bogs, but when i step on the gas it picks up like it should. I'm going to try to unplug the O2 and see what happens.

This is a good thread, good info

 

sorry to thread-jack, but my b18c is running one O2 with no check engine light on a pr3. Once in awhile it stumbles around 3500 on the highway. I always wondered why there was no CEL, any thoughts?

 

It depends on your ECU. If you have OBD0,1,2 it is different. I can run my B16a1 with the O2,s unplugged and the CEL will never come on. I don't remember when they programmed the ECU to throw a code for no signal. Maybe someone else knows that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr. S &raquo;</TD></TR><TR><TD CLASS="quote">Try checking your fuel filter, like the other guy suggested, and also check your ignition components, especially the notorious Honda igniter.</TD></TR></TABLE>

How do you 'check' a fuel filter?

I had this exact problem on my car, i wired the o2's backwards. Switched the pin outs on the ecu and i have been cherry ever since.

Also, if you unplug them, that should help you to determine if thats the problem, and they probably will never throw a code.

 

I forgot to mention. Even if you have a newer ECU (OBD2) and bad O2's you may not get a code. The O2 can be bad, but still send a signal so the ECU won't register it as bad.

 

good job hughe, that was exactly the problem. i unplugged the one old o2 sensor and the car ran like a gem, so now ive got to get a sensor and pull the manifold off i guess? i don't see any way to get to it with it still on the engine
thanks for the advice, it is much appreciated.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sick hatchem &raquo;</TD></TR><TR><TD CLASS="quote">

How do you 'check' a fuel filter?

</TD></TR></TABLE>

By check I mean replace.

 

Gotcha, thats what i figured, but thought i would double check...

 

After un-plugging the two o2 sensors, and running rich for a little while, will the plugs need to be replaced? Will it be that rich? Are the sensors easy to put in with the manifold off???Later,

 

yea this post is great I am haveing the exact same prob with my new b16. If I am running pr3 do I unplug both o2s or just one to check and see if that is my prob? thanks
Matt

 

Your welcome, I am glad that I could help. I know the next time I do an engine swap I will replace the O2's before I drop it in. It is so much easier to do when the engine is out of the car. Your right about having to remove the header to change them. I actually replaced mine without removing it, but I would not recommend my method. I already know someone is going to ask, so: I took my jack handle and placed it on the O2. Then I hit the handle with a hammer. This breaks the end off of the O2 sensor (ceramic and thin metal) then I put a short socket on the stub that was left to remove them. I put the new ones in and tightend them with a light squeeze of vise grips (not to the correct torque). Again It is best to remove the header. The reason I did not is because mine was frozen up at the B pipe.

Have a good one,

Larry

 

If you don't unplug both and the one you leave in is bad you will still have a problem, so if you want to find out if the O2's are causing the problem you should unplug both.

I ran mine for about a week with them unplugged. Changed the O2's and checke the plugs a week later. They were nice and toasty. You should not have a problem with the plugs.

I am not sure how to check a fuel filter. I replaced mine when I did my swap so I did not have to worry about it. It seams the only way to check it would to do some kind of pressure check.

 

this is a good post, 4 years old and im still responding to it