AudioFunk

So I have a problem. It's kinda complicated but Imma try to explain it as best as I can. So about 8-9 months ago my 1994 Lude was having problems all cause of a bad ground after that was fixed she started to act more weird, she's un- drivable over 10 miles cause I'm afraid she'll stall and I'll tell you why. On a cold start she'll idle fine, nice and smooth no problems, come operating temperature she'll get worse and worse in closed loop. The idle is very bad, but only in stops. She'll idle better but still rough in Park or Neutral. In drive or reverse she'll idle like this. If I stop quickly like at a stop sign or a parking space the idle will get low as hell and stall. One day I was off work going home and I hit a speed bump, I noticed on the way home my idle was smooth, really smooth. I was like huh, that's weird. I got home, forgot to put up my windows, so I turned the key until my dash lights came on and I noticed no battery light. Went to check it out I found the electrical connection that connects to the alternator was unplugged. Everytime It's unplugged the car runs better and idles better and doesn't do what that video shows, so the battery not charging= no crappy idle. I got a voltmeter and checked voltage under load, Idk the exact numbers but here's an example. Let's say the voltage was a 11.4 under load and my engine (H23A1) is running like crap, then out of no where the volt reads at 12.4 and the idle changes, engine looks like it's running better then it goes back to 11.4 and running like crap, also the a/c was on when I did this test the fans turned off as the voltage dropped then came back on, aren't they supposed to stay on the whole time the a/c is on? Then I said ok, It's my alternator. Got the best belt and Alternator I could get at O'Rilleys. Put it on and same symptoms. Didn't get better or worse. The alternator was good. But then there's this, 8-9 months ago I got a CEL for Code 20 Electrical Load Detector (ELD). It came on while driving and never came back after I turned the car off and on again. I checked the code with a paper clip, never has come back on since tho. I heard it's in the fuse box. So I'm wondering if that is my problem? Maybe a EGR problem? What do you guys think? Thanks.

holmesnmanny

Start your car up cold so it's automatically idling 1500 or so and see what the alternator is charging at. Then turn on the headlights and rear defrogger and see what the voltage is. Until the car warms up it's going to be charging in full output mode so it will be giving you all it's got. If it can't handle the load then it's not good and parts store alternators are always a crap shoot.

You can test the eld. It's real easy You just stick a paperclip into the fuse box connector and note the voltage with the connector disconnected, then with just the parking lights on, then with the headlights on.

I don't remember off the top of my head what the voltages are supposed to be but you can find them on a search.

Yes, if the eld is bad then you just need to swap out the fuse box with a car with the same trim and transmission.

AudioFunk

I will check that tomorrow morning, but I think my old alternator was good since I changed it and nothing really changed. I don't think the problem was the alternator. And I checked the voltage a few times on a cold start it starts at a 14.4 on both alternators and as my car warms up the voltage drops. It drops to 10-11 volts.

holmesnmanny

I would bet that the eld is indeed bad based on that. After the car warms up it'll start charging in low output mode and if the eld isn't working correctly it won't tell the car when you have loads on, so it'll stay in low output mode and the draw will try to cause the car to die.

Let's see what your eld results wind up being.

AudioFunk

I got a buddies fuse box and swapped it and it's still the same. Car will still idle better when alternator is unplugged. Before all this started to happen someone swapped my TPS with one from a 1992 accord with a F22A1 engine, turned out that wasn't the problem. Idk if a TPS can cause all this. I still have my old one.

holmesnmanny

Did you calibrate the TPS ? You can't just throw it on. It has to be calibrated.

There are threads in the faq's for how to calibrate.

AudioFunk

I let my engine warm up and I disconnected the TPS, the idle was smooth again. I'm gonna swap out the old one the idiot changed and calibrate the old one.