jimmyenglish

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!

jmacsss

try another computer, your new tps could be defective, i dont understand how it runs fine with the tps unplugged..

rpmraper

did you tune the tps with a volt meter?

jimmyenglish

Hi guys, thanks for writing. Yes, I calibrated the new TPS. It's within spec. The word "fine" might be the wrong word. The car is already so painfully slow anyway if there's a performance hit with the tps unplugged I surely can't tell. With the tps unplugged there is absolutely no stuttering whatsoever at anytime. The only discernable difference was the mega mileage hit. Running the new tps through the range is smooth and uninterupted when checking the voltage sweep or resistance. I'm completely perplexed! Code 7 is the only one that ever shows up and the CEL only came on once when I came to a stop after a powerslide in the backyard. It went off shortly thereafter. Checked it: code 7. Reset ecu. No change.

jimmyenglish

So I finally tracked my issue down to the plug. Some of the connectors seemed a little loose even though it felt pretty tight. Chopped plug off, soldered up a nice set of wires and plugs. Runs perfect. Thanks again guys!

jimmyenglish

So my wire fix didn't work. It's as bad as ever. Hardwired TPS straight to ECU. No change. Opened up ECU to check for cold solders. Looks perfect and new. What else could it be? PLEASE HELP!!!

motegicivic

Was it an OEM TPS or aftermarket?

NOFX

It's in open loop. That's exactly what it would do.

My '88 CRX with CEL 7 did the same thing. I made some threads about it. Tested everything, replaced TPS, replaced ECU, calibrated TPS, wiring all checked out.

Ended up swapping the engine, but the last thing we were thinking was perhaps there was some sort of back feed from one of the other two sensors on that circuit I guess?

Using the same engine harness now with the swap but the new engine doesn't use those two sensors and I've had zero problem in that regard.

You could probably find a used IACV on here, Craigslist or eBay btw.

jdmkha

00000000 my goddddd I am having the same F ing PROBLEM PLEASE HEEELP ME PLEASE. When I checked my tps for smooth voltage sweep instead of the numbers going up from idle .5v it whould go down then up as i gradually open the throttle. example is as reads .50 .60 .40 1.10 .90 2.00 then would do this until wot 4.5v please please help me...did you ever find out what your proble was?? The damn car is totally undriviable with tps pluged. unpluged it drives much smoother but lacks that power. THIS **** IS BEYOND PISSING ME OFF.

jimmyenglish

Hey jd, I'm still having issues. About 3 weeks ago I talked to a honda guy and shared the whole story. He told me to clean the throttle body. I pretty much knew this would have no effect but I did it anyway. It was mildly dirty. Cleaned it to like new appearance and calibrated the tps to perfect spec. Sweep on the tps is perfect.I was optimistic for awhile as it didn't really seem to stutter anymore. Anyway, that lasted a couple weeks and now it's back to the way it was. However, I'm not getting the cel anymore.

I will be forced into an emissions test this July so I'm going to have to get the idle down. Suppose I'll to have to spread my buttcheeks for a new IACV. I wish I could just bypass all this electro-mechanical bullshit. I'm holding onto a microfraction of hope that it'll fix it.

I've posted everywhere (even the Cartalk guys, no response) and no one seems to have a clue. The car is drivable but low speed stutter is ever present. My wife is totally sick of riding in it. Last time she had a cup of coffee and we were doing some parking lot maneuvering. Couple good low speed bucks and she was wearing that ****.

At speed or anything more than half throttle and it runs fine (for the most part). Since I've pulled several new wires through the firewall, I'm going to hook up a switch to the tps. It sounds super ghetto (and very unlike me to be so) but I don't know what else to do. Since I do a lot of mixed driving, when I'm in town I'll just drive with it off and flip it on when on the highway. Totally blows but I'm done ****ing with this. If you ever figure out what's going on PLEASE let me know.

This is a damn shame because other than that, the car is perfect.

Good luck!