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Discussion Starter #1
Ok this is getting me nuts. If it's not one thing it's another with this car.

Here's what's going on...... After EVERY rainstorm, the car will idle fine for about 1 minute. After that the idle becomes terrible and it has absolutely NO power. It feels like it's running on 4 cyls at that point. It will clear up after about 5 minutes of idle or driving, and will be fine. When it's dry out, there is no issue. It feels as if the MAF is not reading but like I said it only happens after the car is parked in a rainstorm.

Now........ Here's what I have going on with the car. I have codes for the o2 heater circuit malfunction on all 4 sensors. I have not been able to find the problem with that. I cleaned the MAF when I put it on the road like 2 months ago so I highly doubt that it would be dirty in that short of a time again, and it really doesnt explain why it only happens when the car is parked in a rainstorm.

I'm at a loss here. This on top of the huff of smoke that I get after idling for a little bit(like at a light), the o2 heater issue, is really pushing my buttons. I love the car, and it was my mother's old car so it kind of holds a sentimental value but I cant have a car that works 80% of the time properly, as it's my DD.

Any ideas?
 

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13's or Mildly Broken
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Check your plug wires - mine does the same thing after I come out of the car wash.

And it sounds like your O2 sensors don't like you at the moment. Any idea when they were last changed?

-Melon
 

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Discussion Starter #3
Wires were replaced when I did the intake manifold like 800 miles ago, plugs have about 1K on them, and both drivers bank O2's were just replaced a month ago with Denso's.


Now.... I have been told by someone to replace teh cats cause they think they are clogging or are clogged. I dont believe that is the issue. I have a feeling it's a wiring issue or a problem with the computer. Which wires should I be testing for the heater circuit on the PCM from this wiring diagram?

http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/06/bb/db/large/0900c1528006bbdb.gif

Also, this says PCM. I was under the assumption that the PCM is teh small black box just under the passanger side of teh dash. Shouldnt it be ECM(the one IN the dash?
 

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I had veeeeeery similar symptoms a while back... http://forums.tccoa.com/showthread.php?t=119202

I really think it was caused by moisture in the plug wells. The problem stopped completely after the PI intake swap with new gaskets (there were slow coolant leaks by #4 and #5 cylinders before). That in addition to the dripping from the poor seal over cylinder 4, I think, is what did it for me.
 

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Discussion Starter #5
I had veeeeeery similar symptoms a while back... http://forums.tccoa.com/showthread.php?t=119202

I really think it was caused by moisture in the plug wells. The problem stopped completely after the PI intake swap with new gaskets (there were slow coolant leaks by #4 and #5 cylinders before). That in addition to the dripping from the poor seal over cylinder 4, I think, is what did it for me.
After reading through that topic it definately does sound like what's going on with mine....... especially this statement...........
One more remark. When the engine is doing its "hoppy" dance which, like I said, shakes the whole car rather violently and I need some power to accelerate, I get the throttle pretty close to WOT (around 80%) and it magically clears up. But, it returns after I start driving normally again until it has time to "dry".
I'm going to go out there tomrrow and check to see if I have any fluid in the plug tubes. When I did the wires I used pleanty of dielectric grease. I have noticed lately though that it has not been running as smooth as it was 500 miles ago. At idle it kind of slightly misses every once in a while. Maybe I have a bad wire too? Lifetime gaurentee so no big deal there.


The thing that kills me is the damn O2 heater circuit malfunction on all 4 O2's. It starts on the drivers side after about 2 run cycles. The passanger side takes about 6 run cycles to trigger off. When I did the intake manifold, it was pissing coolant from just about everywhere. It was bad at the #4, and #8 plug, and was leaking all over where the thermostat housing is. I'm wondering that maybe the wiring going to the rear of the motor that goes to the drivers side front O2 is shorted from coolant getting in there. I know that it was leaking for a WHILE when my mother owned the car. I should pull that harness out of the covering and see what I find......

I'm going to double check the codes and see what I come up with.
 

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Yeah, I thought I used more than enough grease too. The thing is, every time I pulled the wires to check things out, the grease had dried up. I'd check the manifold gasket near cylinders #1, 4 and 5 as well as the heater hose connection at the rear of the manifold. My leaks were at that heater hose connection and at the gasket under the thermostat, but a friend had his aluminum x-over crack and start leaking over cylinder #1. I looked at my old NPI manifold at that point and sure enough, mine was slightly cracked and within months of leaking itself. If it's not one thing, it's another... :rolleyes:
 

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Discussion Starter #7
If it's not one thing, it's another... :rolleyes:
quoted for the truth!!


Well I havent seen any coolant leaking (havent had to add any since I did the intake about 1K miles ago), but that's not to say that it absolutely isnt happening. I'm going to check the wires in common places(#1, 4, 5, and 8) and see what's going on there. I think that I'm also going to tear the wires out of the harness that go to the front o2 and see if they look bad. I have to get the car reinspected by 10-13 so I REALLY need to get the o2 problem fixed so it will pass. That's the only thing it failed for.

I'm not one to go throwing parts at a problem. I like to know WHAT the problem is before I start buying parts, so any suggestions are much appreciated!
 

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Discussion Starter #8
I just checked the plug holes and there's NO water in it, so my intake swap is still leak free. I checked the weather stripping on the cown and it was in place. Maybe I'll take it off and throw a little sealer in it then reinstall just to be on the safe side. I also checked the codes to see if I got a misfire or anything else, and I only have the codes for all 4 o2 heater circuit malfunction.

I have to really dig in and see what I can find with the wiring harness for the o2 issue. I did notice that the harness was rubbing on the intake manifold bolt by the #4 cyl. I have to take it apart and make sure that it didnt cut any wires in there. Although I'm kind of hoping that's the case and it's the o2 heater wire:rolleyes:

I did find why my brand new belt has been squeaking. The belt tensioner is weak, so I just ordered one. I also have to do the drivers upper control arm, and rear brake pads which I'll do this week(hopefully). Slowly but surely, I'm giving life back to this bird. I love the car and would hate to get to the point of no return with it. Point of no return being not being able to get it to pass inspection.
 

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A while back I had an issues with the wires behind the passenger side head; insulation had deteriorated so much on some of the wires to the point that they were bare in certain places. I had a short that prevented the car from starting at one point. I'd definitely look over the harness. Enough moisture inside the harness would be all it takes for any bare spots on your wires to short out.
 

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After reading this topic I figured I would look at a wiring diagram to try to figure out where a possible short or open was. It appears that one signal from the PCM that goes to the O2 sensors, IAC, fuel injectors, and many other parts goes through the EVR solenoid first. Then there is the IAT which also goes to the O2 sensors, DPFE, and octane plug. I would check the IAT first and then check the EVR solenoid. It sounds to me that the IAT is more likely to be the problem.

When it comes to not throwing parts at a problem I look at it like this. If it involves me replacing something that hasn't been replaced and is bound to go bad eventually it isn't that big of a deal. I think this especially when dealing with electronic parts like sensors. Luckily most of them are rather cheap and easy to replace so I'd rather start there before messing with mechanical parts or the PCM.
 

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I have codes for the o2 heater circuit malfunction on all 4 sensors.
Any ideas?
This was the rear O2 sensors on my car; I swapped the fronts to the back, and new fronts installed fixed the problem.

If it only happens when it rains, I'd:

Take all the o2 sensor connections apart
Wash them out with clean water
Spray them out with wd40
Coat them with fresh dielectric grease
Put them back together.

Make sure the insulation isn't burnt thru; if the o2 sensor wires are damaged, that's a major problem; o2 sensors don't always throw a code for awhile after they quit working well...


WD40 (or other more paint-and-insulation-friendly electronic silicone spray) works well at chasing water out of wiring; that's what they were originally developed for in WW2. Start at the top, put the tube inside the plastic overwrap, and spray till it comes out the bottom of the bundle. The water will come out with the silicone. Depending on what you use, this isn't real good for the insulation, but it will help pinpoint a problem area. Silicone has a lower surface tension than water, and won't mix with it; so it will force it out of cracks.
 

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Raoul Duke
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When I first bought my '96, it would run like a pig after/during a rain storm. At one point, I had to pull off the road because I was holding back traffic - the car would barely move.
As soon as I got off the road, I had an idea to check the air filter. It was totally wet. The question, of course, is why was it wet? I looked into the tube that extends into the fender from the air box. It had a low point with a drain (which was clogged with dirt, leaves, etc.) and water was standing in that spot. I removed that elbow entirely and I've never had a problem since.

The car was totally stock at this point and, as far as I know, untouched since the factory.

It's unlikely that this is your problem, but the symptoms certainly match.
 

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Discussion Starter #13
I removed the air baffle before I put the car on the road so I doubt that is the problem. That and it only happens after a rain storm when teh car is parked. It doesnt happen when I drive the car.


Funny enough.... we had some heavy rain come in last night and today it didnt do the sputtering at all. I'm at a loss here.
 
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