Hi everyone, I have a 92 CIvic CX that's stone stock. I bought the car with 130k on it and from the get go had the erratic idle issue. Checked the IACV and all tests that go with it. Still crazy. Too expensive to replace. I can live with it if that's what's causing it.

The bigger issue is the very regular bucking at low speeds. I replaced the TPS. No change. I still get an intermittent code 7. I unplugged it and the car runs like new. Did this for awhile but my mileage went from 40 hwy to around 26 hwy. Plug it back in and the good mileage returns as well as the herky jerk, low speed (and occasionally at speed) micro stalls that are pissing me off to no end.

Today I went through all the tests in the book: I hooked up a test lamp to all the wires, from sensor to right shock mount connector, then to the ecu. .5 -.45 volt at the ecu. Jiggled the crap out of the wires, triple checked the connections at the tps plug. Nice and tight. Light never wavered during any of the tests.

So I'm at the end of the troubleshooting part of the manual. "Substitute a known good ECU and recheck."

Is this really possible? The car runs so good with the TPS disconnected but if I'm stuck with only 25ish mpg I'd like something a whole lot faster.

Another interesting thing I should add. When it's damp/humid, until it warms up, it runs perfectly fine.

Please help!

Thanks and great forum!

So I'm also

 

So I'm still battling this issue. I've talked to a bunch of honda people and no one seems to have any ideas.

I've pulled new wire to the tps. Soldered straight to the tps and computer. No change. Car bucks and jerks at low speed until the CEL comes on. At that point the TPS falls offline and the car runs great (except for mileage goes down toilet). CEL always says code 7. TPS is new, In fact, I replaced it because the old one was doing the same thing. Same intermittent code and everything. Now I wish I wouldn't have.

I opened up the computer to see if there were any cold solder joints. It looks absolutely brand new.


Cap, rotor, plugs, wires all very recent. Plus, like I mentioned before, once the CEL comes on (or if TPS is unplugged), car runs fine. Low speed driving is perfectly smooth.

Surely somebody has had a smiliar issue. I don't know what else to do. I have very little money and can't afford to start buying parts all ***** nilly.

Worst case scenario: If I pull the plug when the tps is, say halfway, will the computer just stick to the last known settings? Since most of my driving is never more than half throttle perhaps I could stave off the mileage hit I'll incur by driving with the TPS disconnected. Which, I'm afraid, I may end up having to do.

Ready to put a sledge through this bitch. PLEASE HELP!!!

 

I can understand your frustration. I have been dealing with numerous wiring issues recently too which come and go randomly. I am getting CELs for the TPS, CKP (crank positioning sensor I think), ECT, and IAT.

Anyways, the only thing I can think of would be to try a different throttle body with a known working TPS sensor attached to it. D series TB's should only be like $20-$30 with the TPS on it.

 

Thanks for the reply. How hard would it be to just rip all this **** off and just put a carb on it? I rebuilt my old 75' CVCC that way. $100 2brl weber and it was fine. Mileage was comparable.

Is this possible? I can't afford to start buying parts I don't know if I need.

Thanks again

 

Well, I have never seen a carb'd 92+ Civic. I have no idea what I would take to do it, but I would guarantee it would be more costly than buying a known working TB with a TPS on it. I am sure other members can shed more light on this.

 

Yeah, I guess that'd be ridiculous. Just so frustrated. I've searched and posted everywhere, watched a zillion videos and no one seems to have a clue.

 

The issue does should extremely odd. Especially since you have swapped out sensors and you are using a multimeter for testing. The ONLY thing I can think of now would be assume that the mechanism within the throttle body that turns the TPS sensor is not functioning properly.

Would you like me to move this thread over to the "Mechanical Problems & Technical Chat" section? If should get more views and help in there instead of the "Engine & Internal" section where a lot of people talk about modifying their motor to gain more power.

 

Yeah, that'd be great. I guess I posted in the wrong forum.

Today I took the throttle body off, cleaned the crap out of it and recalibrated the tps. TB looks real good. The sweep on the tps is nice and smooth. No diff except now the idle is high. Still bucks on accelleration/low speed cruising.

It's never idled correctly. When I bought the car a year ago, I took the IACV off and cleaned the crap out of it. It clicks when you hit it with voltage. Turned the cold start valve thing in all the way. Dropped the cold idle down (which was like 3k).

Went after vacuum leaks with propane and a hose. Nothing. All hoses look good.

Does the computer remember the last know tps settings if you disconnect it while it's running? Runs perfectly fine with the tps unplugged but I lose 10mpg. Is there a way to maybe just set it to the low/mid position? (where I do 95% of my driving?)

Thanks for all your help. I'm totally at wits end.

 

So the other thing that's driving me crazy is that, while I've scoured through a million website/posts dealing with almost the exact same problem, I haven't found a single, solid solution.

I was intrigued by the distributor idea but if it were bad how is it that it runs so good with the tps unplugged? Cap,rotor, wires, plugs all very new. I remember throwing a new $95 igniter at my 87 Integra and it didn't change shhit.

Guess I'm just thinking out loud. THanks anyway...

 

Moved the thread for ya. Hopefully, some more experienced member will be able to chime in.