I need some help

[Willard]

Ok, so for quite a while now the ex hasn't been running right. I have either a weak or dead cylinder. It has these two codes:

176 - O2 sensor fault, always lean

332 - Insufficient EGR Flow detected

Now the hard part. I have replaced plugs, wires, coil pack, O2 sensors, cleaned MAF, replaced EGR sensor, sollenoid, valve, and tube ( i broke the old one), and still no help. I should probably check out my wiring on the O2 sensors, that might possibly be the problem, but for now I'm assuming it's fine. The dead cylinder has compression, and there are no abnormal noises coming from the engine. It should be noted the dead cylinder is the second one on the passenger side, so it should have no effect to EGR. I'm stumped. I can't figure out what it could be. Any help anybody has would be appreciated.

 

[manaen]

How do you know the cylinder is dead?

332 is probably your DPFE sensor, or one of the vacum lines that goes to it is leaking.

176 can be caused by many things, vacuum leak, low fuel pressure, clogged fuel filter. The O2 sensor is not the problem it is what is reporting the problem. You need to figure out why the engine is running lean.

 

[manaen]

keep us posted

 

[Willard]

I know the cylinder is dead because there is an obvious dead spot when feeling the exhaust and it runs like crap. It has a hard time staying alive when going into gear and has no power. It is an obvious miss. The DPFE sensor has been replaced, as well as all the EGR stuff, so it SHOULD be fine, but who knows. I would say it's a fuel filter problem but it seems to be getting plenty of gas with the mileage its getting (something like 12 when it used to get in excess of 15). I do wonder about the fuel pressure regulator, although it runs smooth except for that one cylinder. Ran fine before this problem. I also wonder about the injector for that cylinder, as it could likely be failing after 208,000 miles. I should note the spark plug had a light coating of gas on it when I pulled it, and it smells rich when it's running. I know which cylinder it is because If I pull that wire, it makes no difference in how it runs. This problem has been sneaking up for awhile now. It would do it only after a long trip, then only after it was hot, then once it got warm at all, then all the time.This leads me to think that the problem is electronic, but I don't know what it could be.

 

[manaen]

The only way to detect a bad cylinder is to do a compression check, you cannot feel the pulse in the exhaust. I suggest you test the fuel pressure, the FRP could be giving you way too much pressure which would feel like a miss, and explain the excess fuel usage. Also do a vacuum test to see the state of the engine that will show you all sorts of usefull information.

 

[Willard]

thanks, i guess i'll have to check to fuel pressure. and just to clarify what i meant by dead cylinder is that it was missing, or not firing. I did not mean to imply that it didn't have compression or anything, I just mean that cylinder doesn't work for some reason, even though it has compression. sorry for the misunderstanding. anyways, i guess i'll have to do the fuel pressure and vaccuum test to see what i've got

 

[1IronMike]

New plugs don't always work! Same with new plug wires!

 

[Willard]

New plugs don't always work! Same with new plug wires!

Yea but this has happened on more than one set of plugs, and does it with my old and new wires, so I'm pretty sure that isn't the problem. Also, I've tested for spark at the plug, and it is fine.

 

[manaen]

what did the plugs look like that you switched, how where they burning?

 

[manaen]

Oh and perform the OHMS test on your coil pack to make sure there are no dead coils.

 

[Willard]

Well, i finally got around to checking fuel pressure. Put the gauge on, started it up, and the reading is....0. I thought the gauge was broken, but it was new and I tested it and it was fine. So I changed the fuel filter, and now I have almost 40 psi throughout the RPM range. It has more power, but still misses on the same cylinder. I plan to check out that plug, as it may have been soaked in gas too long and wont work, but are their any other suggestions? Vacuum is also fine, as the FPR works perfectly. I am running some fuel system cleaner right now, and plan to do a little seafoam treatment in case something is gummed up from having no fuel running through it.

 

[YourNameHere]

clogged injector?

 

[Willard]

i thought that too, but it was wet before, and now it has fuel pressure, it isn't. maybe something got shoved in there when it finally got enough pressure.....hmmm....i don't really wanna take off the upper intake if thats not the problem, though. all the other plugs look fine, this one is clean, like its not burning

 

[YourNameHere]

Crank position sensor?

 

[Willard]

i've thought about that before, anyway to eliminate it from the mix?

 

[manaen]

The injector is sticking open, happened to me, you need to pull the injector and have it tested. that is why the plug is wet, spray from an injector will never wet a plug unless it is sticking/leaking badly. I had a similar problem and it cost me an engine due to a comedy of errors. take out all the injectors and have them tested and cleaned, it is worth it.

 

[Willard]

wouldn't it not be able to hold fuel pressure when off if the injector was stuck open? i haven't done it for a long time, but I know it hold pressure for a few minutes.

edit: forgot to ask, where is a good place to go to get injectors tested? just the auto parts store?

 

[suprcharg97]

Should be able to conduct a injector leak down test. What the fuel pressure when the engine is shut off to watch it drop off. I had rebuilt a 93 sport, kid destroyed the engine. I had rcengineering clean and test the injectors before and after. Cost $100 but worth it, wasn't sure if there might have been a bad injector and caused a lean condition in a cylinder resulting in a over heat condition in one of the cylinders.

 

[suprcharg97]

the concern with the egr code could be plugged manifold (carbon) not allowing the flow of exhaust gas

 

[manaen]

Should be able to conduct a injector leak down test. What the fuel pressure when the engine is shut off to watch it drop off. I had rebuilt a 93 sport, kid destroyed the engine. I had rcengineering clean and test the injectors before and after. Cost $100 but worth it, wasn't sure if there might have been a bad injector and caused a lean condition in a cylinder resulting in a over heat condition in one of the cylinders.

Exactly

do the leakdown and see what happens, when my injectors where at their worst the pressure would drop rapidly when shut off.