1991 Honda accord misfire

[Kev1990]

Hello I purchased another cb7 1991 Honda Accord LX F22A1 one owner 142k miles for 500 bucks a nice red color with tan interior love the car so far but here's it's problems

I started out by checking the CEL & TRANSMISSION codes for CEL got 7 and 17 for the transmission code 4 please note 7 & 4 are fixed, it was the speed sensor and with code 17 I reset my ECU twice before changing the speed sensor and it would set off TPS code instantly. Some odd reason since I fixed the speed sensor code 17 hasn't returned.

Anyways onto it's ONLY problem. Cylinder two has a bad misfire almost to the point where it's a dead cylinder and here's the symptoms on cold or warm engine it misfires essentially running on three cylinders at idle-2k rpms only three cylinders 2k and above runs nice and smooth on all four cylinders actually has a lot of power so I don't think it's a detrimental problem internally.

Here's what I've done so far to try and resolve this.

Check for spark

Check fuel injectors even swapped them between cylinders and the problem was still only on cylinder 2

Swaped the finned fuel injector control box from my 90 to 91 just for the hell of it

Changed spark plugs and wires

So what do you guys think it could be?

Could a bad TPS cause this exact problem a dead spot like I've heard its known to do before on other cars with a bad TPS?

Could something be damaged internally? It runs-drives great just idles real rough shakes and idles low sometimes due to only running on 3 cylinders.

I love this car so far and hope this isn't a severe problem I fully inspected the car itself throughly

No engine or transmission leaks.

No problems at all with any suspension-steering-brakes in fact the rotors & pads are new, no cracked-torn boots or any play in the front end at all.

All fluids in good shape but the brake fluid it's a bit dark.

Interior is like new and tan witch I love exterior paint is in like new condition execpt for what little rust it has.

Anyone with any ideas please post up. Thank you in advanced all of your help is greatly apprciated and I will be posting pictures of the car once it's cleaned up.

Forgot to mention any point in time I can bounce the engine off the rev limiter and I know that's a known sign of a bad TPS.

[93redcb7]

Hello I purchased another cb7 1991 Honda Accord LX F22A1 one owner 142k miles for 500 bucks a nice red color with tan interior love the car so far but here's it's problems

I started out by checking the CEL & TRANSMISSION codes for CEL got 7 and 17 for the transmission code 4 please note 7 & 4 are fixed, it was the speed sensor and with code 17 I reset my ECU twice before changing the speed sensor and it would set off TPS code instantly. Some odd reason since I fixed the speed sensor code 17 hasn't returned.

Anyways onto it's ONLY problem. Cylinder two has a bad misfire almost to the point where it's a dead cylinder and here's the symptoms on cold or warm engine it misfires essentially running on three cylinders at idle-2k rpms only three cylinders 2k and above runs nice and smooth on all four cylinders actually has a lot of power so I don't think it's a detrimental problem internally.

Here's what I've done so far to try and resolve this.

Check for spark

Check fuel injectors even swapped them between cylinders and the problem was still only on cylinder 2

Swaped the finned fuel injector control box from my 90 to 91 just for the hell of it

Changed spark plugs and wires

So what do you guys think it could be?

Could a bad TPS cause this exact problem a dead spot like I've heard its known to do before on other cars with a bad TPS?

Could something be damaged internally? It runs-drives great just idles real rough shakes and idles low sometimes due to only running on 3 cylinders.

I love this car so far and hope this isn't a severe problem I fully inspected the car itself throughly

No engine or transmission leaks.

No problems at all with any suspension-steering-brakes in fact the rotors & pads are new, no cracked-torn boots or any play in the front end at all.

All fluids in good shape but the brake fluid it's a bit dark.

Interior is like new and tan witch I love exterior paint is in like new condition execpt for what little rust it has.

Anyone with any ideas please post up. Thank you in advanced all of your help is greatly apprciated and I will be posting pictures of the car once it's cleaned up.

Forgot to mention any point in time I can bounce the engine off the rev limiter and I know that's a known sign of a bad TPS.

i would compression test it, as the comp. could be low or leaking past the rings. Normally you can rent comp. tested at the local parts store

[Kev1990]

Dam would that make sense though even though it runs on all four cylinders at 2k+? I'm thinking its something else because the car did sit for two years.

[Kev1990]

So the TPS is a bit out of whack on this car.

6-6.1 volts at idle

Ranges from 4-4.5 volts at WOT

I'm going to start by replacing this part first

From what I know it isn't hard to replace and this will be my first time taking off the throttle body so hopefully it all goes well. Anyone with any tips plox post lol

[Kev1990]

So I changed TPS yesterday went to calibrate it. Whenever I go and calibrate it to 0.5 tighten it down so it doesn't move I go to WOT and its at 4.3 or so bring it back down to idle and it goes back to 0.6? Same thing as old TPS sensor. What could be the next solution guys to calibrate this properly? What could be wrong?

[lbus9168]

You aren't calibrating it correctly. Read this. Its for a d series but same rules apply.http://www.ozhonda.com/forum/showthr...age-on-the-TPS

[Kev1990]

Your right LOL I apologize for being a dimwhat its what working overtime and 20+ hours of no sleep does to me ahahaha. Anyways im still having a problem with it. I will set it 0.45 at idle and its still like fluctuating if I have the energy I will try to fix it after work today or wait til my days off no point in trying to kill myself lol.

[lbus9168]

Let me know how you go!

[Kev1990]

Still fluctuating so next suggestion would be whole new throttle body and sensor correct? But why is this one fluctuating at only 140k and my 222k 90 is still perfectly fine lol. The throttle body has a problem fluctuating at idle.

[lbus9168]

I'd just clean everything, the fluctuating issue your talking about is that every time you rev it the tps won't go back to the correct measurement, right?

I would clean the throttle body out as much as possible, and if you haven't already I'd replace those tps screws with screws so that you can put decent torque on it.

You may require a new sensor but I doubt it. Id try just cleaning everything.

[93redcb7]

So I changed TPS yesterday went to calibrate it. Whenever I go and calibrate it to 0.5 tighten it down so it doesn't move I go to WOT and its at 4.3 or so bring it back down to idle and it goes back to 0.6? Same thing as old TPS sensor. What could be the next solution guys to calibrate this properly? What could be wrong?

well the first time i changed a TPS i just slapped it in there and didnt put the little prong on the TPS in the little "l l" spot in the throttle body spot, so make sure you did that. then if it keeps moving all over the place. i would replace the sensor

[Kev1990]

Hmm. Yes whenever I go from closed throttle to WOT it goes up to 0.6 and I already thought it could be sticking and not closing all the way but when I check the cable it is fully closed.

[lbus9168]

Yeah, sounds like the sensors probably gone. I'd still try cleaning and retying everything first, might be the springs that's gone. I don't know of a way to test if the tps is good, sorry.

[Kev1990]

Its fine thank you for your help. But anyways after doing research on this I see many people saying to set their TPS idle voltage to different ranges 0.45-0.48-0.5 so witch is it? LOL I may just test my blue 90 again and use those readings to correctly calibrate the new sensor if need be. I may just buy a new throttle body as there's a local one for sale as of earlier today for 25 bucks vs the 75 my local junk yard wants lol.

[Kev1990]

Just wanted to UPDATE this post so its not left hanging

New throttle body+ OEM TPS sensor worked great solved low rough idle and the misfire was clogged EGR ports and valve.

Now I'm still having a very slight misfire but I still have yet to change the valve cover gasket and spark plug tubes as they all have oil in them.

So I hope the oil in the spark plug well's are what is causing the minor misfire I have still.

Will be doing the work tomorrow and will post results thank you for everyone's help so far.