Puzzle: vacuum leak, injector crud, or O2 sensor fail?

[user removed]

Injector connection? Make sure you mentally note the precise thing you did that "fixed it", cause it ain't fixed until you clean that connection thoroughly. If you can't find a ground from a valve cover bolt to the radiator support, MAKE ONE. You can't have too many grounds. My 84 CRX had a bad ground when it was built. Right radio speaker open circuit, factory new wiring harness. I just added a ground.

Also no need to garden hose the engine, a spray bottle like windex is fine. You could damage the engine if done completely wrong.

regards
mech

[2000mc]

Originally Posted by Old Mechanic

Injector connection? Make sure you mentally note the precise thing you did that "fixed it", cause it ain't fixed until...

If it was mine, I wouldn't be disapointed to end up eventually replacing the connector w/ pigtail, and possibly the component it's hooked up to. Considering how much trouble you've gone through. Of course if you find a broken or chaffed wire, maybe just a simple wire repair. Either way I would continue pursuing this issue until it's resolved better than just getting it to go away for now.

[California98Civic]

After 20 or 25 miles of normal operation, the problem returned as I began the return commute. I stopped repeatedly, checking one connection at a time until the problem went away again. It turned out to be the connector into the MAP sensor. Back in March or April, when I repaired the fuel pressure regulator the second time, I relocated my extra brake booster and it seems the vacuum line began to conact and stress the wires into the connector for the MAP. Since it was behind and under the air cleaner box, against the firewall, I did not notice. As soon as I repositioned the vacuum line and reattached the MAP sensor connector, the problem went away.

Perhaps the problem is solved, but only driving will "prove" it.

Thanks!

James

[phh]

It's been a while since your last post. Is it fixed? Anything new to report?

My wife's car is experiencing the same problems. Since it's an 1989 model, the on-board diagnostics give limited info. I've taken many of the same steps as you but so far no success. I'm checking the wiring harness next.

Thanks!
Peter

[California98Civic]

Originally Posted by phh

It's been a while since your last post. Is it fixed? Anything new to report?

My wife's car is experiencing the same problems. Since it's an 1989 model, the on-board diagnostics give limited info. I've taken many of the same steps as you but so far no success. I'm checking the wiring harness next.

Thanks!
Peter

The problem has not returned. Maybe take a look at this other thread and the responses... if you are not familiar with this technique for pulling codes on OBD1 and OBD0, I bet this will help you get more info: http://ecomodder.com/forum/showthrea...tml#post487287

[some_other_dave]

89 would be non-OBD. The only way to check the codes is to pull up the front of the passenger's carpet and look at the ECU when the key is on. There is a window in it, with an LED that will blink out the codes. No long/short blinks, just count the number of blinks until it pauses.

Generally the codes are only blinked out if the check-engine light (CEL) is on.

-soD

[phh]

Originally Posted by some_other_dave

89 would be non-OBD. The only way to check the codes is to pull up the front of the passenger's carpet and look at the ECU when the key is on. There is a window in it, with an LED that will blink out the codes. No long/short blinks, just count the number of blinks until it pauses.

Generally the codes are only blinked out if the check-engine light (CEL) is on.

-soD

The car is actually a Mitsubishi Mirage rebadged as an Eagle Summit, not a Honda. I was able to retrieve the trouble-codes with a voltmeter. Unfortunately the codes aren't concise enough and I still need to diagnose by hand (ugh!)

I used California98Civic's post as a rough guide and found it helpful.

[some_other_dave]

Hahaha! Whoops, I assumed you were talking about an 89 Civic, since the thread started on Civics.

-soD