essay0ns

Hello everyone,

I have been searching the archives and internet and can't seem to get a grip on the problem.

I'm hoping you can help.

Victim: 1990 Civic DX 1.5 liter, duel point Fuel injected, with 313,000 miles. The engine is stock. It's been my daily driver for two-and-a-half years.

Symptoms: Hesitates while driving, surges when at idle, difficulty with starter - sounds like its having to work much harder than usual.

It's been surging for a couple of months. I have replaced the IACV with a used one that I cleaned with carb cleaner. It worked well for a couple weeks and then started up again. I am starting to see a pattern though. It seems to do it after my drive home from work (~ 60 miles) and when the headlights are on.

I have also noticed that the UFO shaped unit under the air intake that attaches directly to the throttle seems to be sticking. I have cleaned it several times with some success but the problem always returns. I have also had some success with fuel additives to clean the fuel injection system.

In an attempt to resolve this problem I took it to the shop and had them check the battery and the alternator hoping that starter problem was related. They said that my voltage regulator was failing.

I replaced the alternator (since the voltage regulator is integral to the unit) since it was still under warranty and replace the spark plugs with iridium and the roter and distributor cap.

I drove 60 miles to work without any problems (ran really smooth) but I thought I noticed a couple moments where it felt like it missed. 3 hours later when I left work the starter still seemed had to work really hard to turn the engine over. On the way home the miss become very pronounced, increasing in frequency the further I traveled. In addition when I pulled into the driveway the engine started to surge again.

No codes at all. I keep checking but none.

From what I have gleaned here, the problem could be one of these things:

*Hoses - old need to be checke and at least cleaned
EGR Valve
Fuel Pump
Fuel Filter clog
ECU
Fuel Injector clogs
Coil
Ignition control Module
*Battery Cables - they're old and need to be checked
*Idle air control valve (IACV) - I have a spare I'll clean up and try
Main Relay
Spark plug cables - old but seemed ok
Fuel injectors
Starter
*Distributor Cap & Roter


I would really appreciate it if you could help me narrow this down a bit. The things with the * are the things I will be working on immediately.

bbarbulo

your starter problem is the ELD unit - electrical load detector. it's supposed to tell the alternator to run harder to make up for the current draw. hence why your problem is more pronounced with the lights on - the alternator just idles despite the increased demand for power. i can't recall where the ELD was in a 4th gen, it's been a long time since I owned one - my guess is the back side of the fuse box under the dash, or in the main fuse box under the hood.

that should take care of part of your problem

bbarbulo

oh ya, the surging, could be anything from an air bubble trapped in your FITV (fast idle thermal valve) or the drained voltage causing other problems. fix one, then go after the other.

essay0ns

Wouldn't the missing have been present before I replaced the parts? Replacing the controller that's attached to the throttle is doable, I have the part.. but I'm not certain we are talking about the same thing.

I'll post a picture with existing conditions and the questionable parts. I'll see if I can find that ELD unit too.

Thanks, I'll see what I can do.

essay0ns

Here are some pic's

This is the little bugger that I think is causing the surging. You can see it up under the plenum on the intake manifold attached to the throttle. I'll be replacing it tomorrow and the hoses weather permitting.

I also have a pic here of the fuse box... i haven't found anything that relates to an ELD even when I search the internet for this year and model civic.

Any idea's on that ELD?

essay0ns

Well, I think I got it fixed. Here's what I did.

The alternator did test bad. It was under warranty so it was an easy fix but it didn't stopt the surging. Next I replaced the starter. It was going bad so that made sense. I had already done a tune up - cap, roter, plugs, fuel filter, oil, etc but that didn't help. I replaced my spark plug wires with some really nice ones off ebay (10.2 mil) and still didn't solve the problem.

Finally I pulled the ignition coil. Examination reveal cracking around the case. I am still not certain that was the problem but replaced it due to it's condition. I also replaced the gasket around the distributer cap. It was brittle and missing most of it's parts. Lastly, I re-installed my old distributer cap and rotor.

I drove it to work yesterday and had no problems.

I suspect that the missing was a result of poor quality distributer cap and rotor. I did some swapping back and fourth with some positive results. The gasket failure and the ignition coil may have been contributing factors but I am unable to definitely assign blame to those parts.

Thanks for your help.


Essay0ns