I have an 85 Camaro Iroc with the TPI 305. I've done just about everything a tune up consists of. Recently, I did the cap and rotor and probably about 5 months ago (6K miles) I did the spark plug wires, plugs, fuel filter, and oil change. This car has about 136K miles on it. The engine is not running right. It sounds like it is missing. I checked the spark plugs by pulling each one out and surprisingly each plug is getting a spark. HOWEVER, all 4 cylinders on the passenger side of the engine (which are all the even cylinders) have ALOT of carbon built up on them - as compared to the odd cylinders which appear to be burning clean and normally. Now, on the passenger side of the engine, there was a bad exhaust manifold leak that wasn't assessed until about a month ago. So this means I, being a newbie, drove the car about 6K miles with a horrible manifold leak, not knowing the damage it can cause. Now, the exhaust leaks are fixed, and my catalytic converter has been cleared. I checked all 8 injectors by listening to them through a screwdriver while the car was running and heard all 8 injectors ticking. I also tested the resistance on them and they were all about 16.5 ohms. The car just does not run right. When it idle's, it shakes the hold car back and forth, not nice and smooth like it was before. Also, when I take it down the road, when accelerating at all, the car shudders horribly but smooths out when I stop acceleration. The car also does this weird shuddering even in neutral when I hit the throttle so I know its not my rear end or transmission. I'm thinking this might be fuel or injector related but I can't be sure. I hope that somebody will take the time to read through this long and boring thread to help me.

 

I think if you have an exhaust leak on the passenger side, that would probably explain that side running pig rich. Since you fixed the leak, i'll move past that.
I imagine you've already changed all 8 plugs? Now they are 8 new shiny plugs?

ok, so lemme get this straight, it started running poorly as of..? Days ago? So during the last 5 months, with the new cap, rotor, plug wires, plugs, it ran fine. You only recently fixed the exhaust leak, and RIGHT AFTER THAT, it started running badly?
I'd guess you swapped a plug wire when replacing your exhaust manifold, that would explain the shuddering and whatnot. Recheck your plug wires.

 

Thank you for the reply! I was so afraid that I had burned my valve seats from running the car with that exhaust leak and that was why my plugs were fouled. But what you said makes sense about running rich on the side of the leak.

Yes, the car started running even more horribly after I fixed the exhaust leak. The car was not running so great even before I had fixed the leak. Also right after I fixed the exhaust leak I inspected the plugs and saw the 4 fouled ones. I took all 8 plugs out and cleaned them off with gasoline but did not replace them. I put the 4 previously fouled plugs into the opposite side of the engine and put the cleaner plugs in the side of the engine which previously had the exhaust leak. I did not replace any of the plugs. They are expensive plugs and my Dad insists that they aren't the problem BUT he is not a mechanic.

 

ah, expensive plugs you say? That can be part of the problem. These cars like the cheap plugs, it's win-win really. Grab some nice Delco R45TS's, or whatever your car is spec'd to use. The copper plane jane ones.

Hmm, this ones getting me scratching my head. You've verified spark at each plug. You've verified the injectors, which i'm hoping means fuel is a-OK.

I'm assuming you're not getting a check engine light? I'm thinking perhaps the O2 sensor is out of whack, or dead, from the leak? (wait, O2 is normally on the drivers side right?)

I'd still trace the wires from distributor to the plugs, double check to see they're not mixed up.

Lets see if any TPI experts post up.

 

Any chance that there might be something stuffed up in the exhaust manifold that could be hindering the flow? Was it a small leak or more like "well its 2" away from the motor and this animal was half way in it" ? Sounds like it might be plugged or a wire got moved.

 

you said you replaced the spark plug wires, did you space them out? i know with Chrysler if you dont space out the plug wires you get induction between them, it will arc between wires and fire on the wrong cylinders, happened to my 95 ram 1500, she couldnt even make it up a hill she was missing so bad. i went to checker auto bought some plastic spacers for about $8 and that fixed it completely. also just because an injector is ticking doesn't mean its atomizing properly, thats a bit of miles you've got on them, they could just be dumping liquid causing your car to run like sh**

 

OK, went to advanced auto and picked up new plugs today. Came home and took the old plugs out and installed the new ones. Once again, the 4 plugs on the passenger side of the engine looked more moist than the ones on the drivers side, but not soaked or anything. I also re-checked my plug wires and they are going to the correct cylinders. Fired it up and it doesn't run any different - still just as crappy.

Later, after quitting on the engine for the night and working on my shaved door handles, I noticed some liquid under the muffler. Now, I only had the engine running for maybe 2 minutes so I'm HOPING that it's not antifreeze but it did look a little green.

Now I'm thinking maybe my head gasket is blown on the passenger side head. Or the head is warped or cracked. After all, during the summer when I was driving the car with the exhaust manifold leak, I also neglected to change my thermostat which in turn, made the car run hotter than it should have.

Would a blown head gasket make my car run poorly like this? Shuddering at cruising RPM's, hesitating, and lack of power? Also, the idle doesn't fluctuate in RPM.

Now, I'm just not sure what to do...

 

Boom! There we go.
I was noticing you said before they were black, but WET is a different ballgame. You've got an intake manifold leak. If you overheated the motor, maybe a head gasket. I don't think that's the case though, you say you didn't change the t-stat? If it was working, then you don't have to change it... If it failed open, also, can't overheat the motor that way.
Check the oil, if it's milky, maybe it's a head gasket, but if it's clean, it's just an intake manifold gasket. That would dump coolant into the combustion chamber causing a miss, and or could have a vacuum leak.

 

I thought it may have been my intake manifold gasket but when I ran the engine and sprayed WD40 all around the intake, it didn't rev up at all. With my grand prix I used to have, that's how we found out it was an intake manifold gasket leak. Could it still be an intake manifold leak? So this wetness in the cylinders is coolant from the intake then?

 

It's rare for an intake gasket to leak directly into a cylinder, without leaving PLENTY of other evidence of failure elsewhere. Look at a gasket, and you'll see why. The coolant passage is about 8 times closer to the exterior of the motor than it is to the FIRST intake port.

Then, it's ALL BUT IMPOSSIBLE for ALL 4 cylinders on one side, to get coolant into the intake ports. Again, look at the gasket, and imagine what it would take to get that to happen.

That said, I doubt your problem is the intake gasket leaking coolant into all 4 cyls equally.

Liquid under the muffler = condensation; totally normal. Ignore it. Burning gasoline produces 2 chemicals, primarily; water and CO2. The water condenses when the system is cold.

It is possible however, for the intake gasket to fail in a different way, and get OIL into all 4 cylinders. Again, look at an intake gasket; note that all 4 intake ports are adjacent to the CRANKCASE across the bottom. If the hardware is loose or the surfaces of the intake and head weren't machined quite perfectly, the gasket could easily be leaking across there.

If it's gunking up the plugs THAT FAST, and the cause is fuel, then your gas mileage would be literally in the gallons per mile, not miles per gallon. If your gas mileage is normalish (15 mpg around town & low 20s on the highway, or better) then you don't have a FUEL problem.

I'm betting it's oil.

Another very common problem that afects all cyls on one bank, is for the oil drainback holes from the rocker area under the valve cover, to be plugged up. This will cause the VC to literally FILL UP with oil, until it reaches such a level that it can drain back through the push rod holes. Pop the VC off and see if it's clean under there.

See my signature for troubleshooting advice.

 

OK, got my manifold off and my gaskets look NASTY. Before I put my new gaskets in I wanted to ask a few questions. Just in case I do have a blown head gasket on the passenger side of the engine, should I just replace it while I have my intake manifold off as well?

Also - looking at where my ?valve pushrods? go down to the block (I'm no mechanic!!!) seem like they might be out of whack. Down by the block, there is a small metal cylinder which sits around the pushrod and looks like it should be pressed into the block. Now, only a few of these cylinder things look they are pulled out a bit. On the passenger side only one is pulled out, but on the driver side there are 3 or 4. Also, on the valves that those cylinder things are pulled out, those valves seem to be tighter than the other ones. Forgive me for not knowing what I'm talking about but I want to learn and that's why I bought the car.

I've attached pictures to help you figure out what the heck I'm talking about. Thanks!!!

 

awww, that's cute, I think that's what my girlfriend said about my engine
Sorry, I had to, that's just an adorable way to describe that stuff down there.

ok, ok, i'm better now, we all need to start somewhere.

Yes, those are pushrods. The thing they are sitting on, is called the lifter. The lifters sit in the bores in the block, and ride on the camshaft. At any point, the camshaft will have different lifters "up" to some degree. Some lifters will be sitting on the "base circle" of the cam, and will be very low in their bore, which will make the 'valves' less tight. (pushrods probably, the valves should be rock solid no matter what).
Other lifters will be up on different parts of the lobe of the cam, and will be at different heights. All completely normal.

Before you put it back together, you'll be cleaning off your cylinder heads, where the gasket was right? Ok, so make sure it's spotlessly clean, like you can't catch a fingernail on gunk, or see any junk there at all. Then mop up the area you took the pictures of, so it's relatively clean. You just don't want bits of gasket to be floating around there. Oh, and clean up the intake manifold mating surface as well, and the "china walls". The part of the block where that rubber gasket was.

I wouldn't bother pulling the heads off and doing the gaskets, I think it'd just be the intake, but it's ultimately your call. Heads add a fair bit of complexity, and unless you had coolant in your oil (milky oil), I highly doubt it failed.

 

The arms that connect my pushrods to my valves is what I think I'm talking about that is loose. I think they are called arms. Well anways, what I meant was that they have a bit of slack on them if I twist them back and forth but it's not like I can push the valves and push rods back and forth. Am I making any sense at all???

 

Yep, rocker arms.

When the cam is on the base circle they will be a bit loose. More so then when they are lifting the valves.

If you want, you can reset your lash, just so you can sleep well at night. (I guess it might be a good idea anyway...)

Do a search on here for the "EOIC" method. That's your best bet.

 

OK, tonight I did injector inspection. Took the fuel rails off and apart and the injectors out. 3 injectors were COMPLETELY clogged. They were packed solid with this really fine rusty crap. The others were very dirty. Also, the fuel rails had tons of this crap in them. Could this have been my major problem all along? I cleaned them with WD40. Also, my intake gasket kit I bought came with 8 o-rings for the injectors but each injector has 2 different o-rings. Which o-ring on each injector should I replace? The one going into the fuel rail or the one going to the manifold?

 

d'ah! That's why I don't usually reply to injected cars problems, I don't know f-all about it, AND IT IS ALWAYS THE SOURCE OF THE PROBLEM.

I figured if you said you tested the ohms on 'em, and they were clicking, then I assumed they were ok. Anyway, yes, that definately was the problem alright. Not sure if there's another way to clean them (you're doing all 8 right ? !)
And I have no clue about the o-rings, but i'd guess the ones you got in the intake gasket set are just for the connection into the manifold. Probably can buy the other 8 for the rails seperately though.

 

***RESOLVED***
OK, got my engine all put back together. In the end, I'm pretty sure my problem was just clogged injectors. My intake manifold gaskets were bad but I don't think they were leaking so bad they made it run like that. Also, when I took my intake manifold off, I had to take my distributer off. In doing so, when I lifted the distributer, the rotor spun like crazy and I neglected to mark where it went before I took it off. So of course, I freaked after I put my engine back together, and the timing was so horribly off that the engine had problems turning over. I had never done timing on a car before and it took my 4 hours to grasp the concept!!!!!

Well thank you every one, my car is running PERFECTLY now. Now I can finish my body work and get some headers! When I first got my car I didn't think it was all much faster than my 94 grand prix. This would be because I was running on 5 cylinders! Now I know just really how much faster it is!

Oh, and I'm guessing the reason that my cylinders looked so clean on the one side of the engine was because it just so happens, all 3 injectors were on that side that were clogged! No wonder they didn't have any carbon on them, they weren't getting an gas!

 

Those are hydraulic lifters which ride on the cam lobes to open and close the valves, totally normal for them to be at different depths because of the cam. Turn the engine by hand you'll see what I mean.

As for the head gasket, if you're going to do one do both, and I'm sure you'll hear if you're going to remove the heads might as well do a valve job. If you don't know the history of the car, I would heed that advice on a 15 year old engine.