mgyip

Asked this question a few weeks back and didn't get much response - I'm frustrated to the point of trundling this car off a bridge but think the problem is relatively simple. The car is a stock '92 Civic DX.

Driving the car home, it suddenly went down on power and started running hot on a hill - didn't overheat, just started to get warm so I backed off the throttle and turned on the heater for a minute. At the bottom of the hill, the engine was no longer running smoothly - still idling but very lumpy. No CEL which is baffling but so is EFI to my old-skool brain.

I've changed the PCV valve, coil, igniter, plugs and O2 sensor but the results are the same. Pulled the coolant temp sensor and swapped computers with no change. Even checked cam timing to ensure that it hadn't slipped.

The symptoms are: starts hot and cold without a problem but the idle isn't smooth. When cold, the idle is smoother and as it warms up, the idle speed drops and becomes more uneven. Under load, the engine doesn't want to rev BUT once it gets beyond a certain point (no tach in the DX so I don't know the rpms), it seems to run fine. When it's not under load, it revs fine but it backfires thru the intake just before it settles down to idle.

Any thoughts on what it could be?

grumblemarc

iTrader: (4)

You mean this thread? I think you got plenty of assistance. You just never bothered to follow up.
https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/92-dx-suddenly-running-like-crap-2985571/

You were also directed thusly "You may want to check for a clogged cat or fuel filter, as well as compression test the cylinders."

Did you replace the exhaust as you stated you were going to? Did you perform the compression test?

mgyip

Yes - that thread.

Exhaust has NOT been replaced - why dump more money into a car that doesn't run. Once it runs, then I'll replace the exhaust. An open exhaust shouldn't cause this type of running issue. That is unless every racecar out there with an open exhaust idles poorly (which they don't).

Since that thread, I changed the O2 sensor and checked the ECU - still runs like crap. Compression test is certainly high on the priority list but why would the car idle poorly but run fine at high RPMs. If a valve is bent or burned, it should run poorly thru the entire RPM band - right? Or is that one of those Honda things that just happens b/c it's a Honda? I've been around VWs (older cars, not the new electrical nightmares) - those cars have similar issues.

I think it's time to dump this car on Goodwill and buy something decent like a TDI.

grumblemarc

iTrader: (4)

Whatever. If you ask for help and don't follow up then that's your choice. I'm only following what YOU said you were going to do. You buy a car that nearly 2 decades old? What did you think was going to happen? You don't listen to the advice that you are given because you know better? What was the point of even asking in the first place?

Trash it and go buy a VW.