Engine is missing terribly..... Runs bad

[designie]

My 1992 started to run really bad about a week ago. It starts to miss and backfire as soon as you try to accelerate or put the engine under load. It runs OK if you hold it at the same speed. It sounded like it did once when I got the wires wet, but the engine is dry. There was some oil down in the spark plug holes from leaky valve cover gaskets, but I don't think that would short a wire would it?

Also, it runs great when you first start it, then it starts to miss worse and worse as it warms up. Then it just sounds like it's on 4 or 5 cylinders.

I don't really know where to start diagnosing. Any ideas? Thanks!!!

 

[shobikes]

At first, everyone else is going to say "run the codes," which will definitely help you figure out if there's any obvious failures detected by the EEC. Find a post by sdpatt, and click on the links at the bottom of his sig.

From the symptoms, I would look into CPS, which can sometimes start shorting when warm. Is your water pump leaking? That would cause problems down there in a hurry. How many miles? 60k done recently? The answers are here, but we'll need more info...

 

[Rockledge]

Yep, run the codes.

And IMHO, it would also be worth your time to remove the oil in the plug wells and check the plug wires to determine if that is causing the misfire(s).

 

[designie]

I don't have a check engine light on, so I don't know if there are any codes, but I'll check. I replaced the CPS, timing belt and water pump not too long ago, but if oil were leaking near the front seal, I wonder if that could cause the CPS to mess up. I think it is leaking oil near the front seal now.

I did remove any oil in the plug wells, and cleaned the plug wires.

I'll try sdpatt's post, too.

 

[autobahnsho]

I had the same problem when I first got my car-

The codes didn't help, but I was poking around and the #5 plug wire wasn't plugged in. Pushed it in and WOW.

3 weeks ago I finally replaced my valve cover seals, plug well seals, and sucked the quart of oil the plugs were sitting in.

Now I have the problem again- 2 of the wire boots are completely cracked, new ones are on the way- I'll let you know if it fixes it. I still dont have any codes, the cylinder test says everythings ok- but it runs like a cylinder or 2 are missing up to around 3k, then it just feels like it's half-powered.

 

[SonicRiot]

You can test which cylinder is misfiring if you have a temp gauge that is accurate and can be aimed without contact with the actual cylinder. (They run about $85-$200, but they are a handy tool in many cases and come with a cool laser pointer!!! The cheaper ones go 0-500 deg.F, while the more expensive go 0-1000 deg.F for exhaust testing.)The cold cylinders are the misfiring ones. This will help you pinpoint the problem cylinders.
Or, on www.midwestsho.com , there is a procedure to test your cylinders after running codes. It will tell you if all is properly functioning. Do it when the car is cold AND when it is hot. If you are yeilding different results, you might have bigger problems than just electrical or spark-related issues.

Also, check each of your wires for wear...if they got wet and were affected, you might have some worn or exposed spark wires and the spark may be arcing or shorting somewhere in the engine bay.
Also, did you check the back plug wells? I know for a fact that my front plug wells must be periodically cleaned because my gaskets are bad. But I haven't done the back ones because I can't just rip off the intake every week. I am dreading looking at the back ones behind the intake manifold when all of this cold, rainy, unpredictable weather clears...

oh. Stupid me. I'm in New England. slap oh

 

[twr]

designie:
My 1992 started to run really bad about a week ago. It starts to miss and backfire as soon as you try to accelerate or put the engine under load. It runs OK if you hold it at the same speed. It sounded like it did once when I got the wires wet, but the engine is dry. There was some oil down in the spark plug holes from leaky valve cover gaskets, but I don't think that would short a wire would it?

Also, it runs great when you first start it, then it starts to miss worse and worse as it warms up. Then it just sounds like it's on 4 or 5 cylinders.

I don't really know where to start diagnosing. Any ideas? Thanks!!!

Oil in the plug well will most certainly short a wire. Even if you clean all the oil out, the wire will still miss fire because it's insulation has been broken down by the oil.

 

[SHO_Driver]

twr:

designie:
My 1992 started to run really bad about a week ago. It starts to miss and backfire as soon as you try to accelerate or put the engine under load. It runs OK if you hold it at the same speed. It sounded like it did once when I got the wires wet, but the engine is dry. There was some oil down in the spark plug holes from leaky valve cover gaskets, but I don't think that would short a wire would it?

Also, it runs great when you first start it, then it starts to miss worse and worse as it warms up. Then it just sounds like it's on 4 or 5 cylinders.

I don't really know where to start diagnosing. Any ideas? Thanks!!!

Oil in the plug well will most certainly short a wire. Even if you clean all the oil out, the wire will still miss fire because it's insulation has been broken down by the oil.

No, not in all cases. Alot of members are periodically cleaning out their plug wells with no misfires. I've been cleaning mine about every 2 months and have found oil about 1/4 up the tube in all wells. I have never experienced or seen any signs of misfire. Granted if there are any cracks in the insulation misfire will occur.

 

[designie]

Well, finally got some warm weather, 35 deg., so I could get the codes from the car.

The KOEO hard code is 557.

The KOEO continuous codes are: 173, 176, 177, 211, 556, 557.

The KOER codes are 116, 137, 536.

I went to the link for the codes. I see a couple codes referring to the fuel pump circuit. I think I've had a bad O sensor for a while, so that could be the cause of some of the rich/lean codes.

A couple codes pointed to BOO circuit and PIP circuit problems, which I don't know what those are.

So that's what I have so far. Could a fuel pump problem be causing maybe some fuel pressure issues?

Thanks for all your help.

 

[masho95]

designie:
A couple codes pointed to BOO circuit and PIP circuit problems, which I don't know what those are.

So that's what I have so far. Could a fuel pump problem be causing maybe some fuel pressure issues?

The BOO circuit is the Brake On/Off circuit, basically tells the car whether the brake is pressed or not. The PIP circuit is refering to the CKP, crankshaft position sensor.
And yes a failing fuel pump definitely could be causing fuel pressure issues.

 

[TimboSHO]

My car started doing the same thing awhile ago..... i checked the spark plugs and saw that it had the original plugs in it!! The gap was almost double what it was supposed to be! It was surprising it still ran. I'm sure you've already checked the plugs, but you have the exact symptoms i had...