Engine shaking

[pontiacfanactic]

1995 2.3L has boggy performance. Engine shakes. Exhaust smells of gas. Barely moves. Pulled spark plugs two of them were blackened other two clean. Replaced fuel filter. Changed ICM. Noted small hairline crack on coil pack housing. Still have boggy performance. No CEL light on. No gas coming out of vacum line from rail regulator. Engine will thump periodically when accelerated. Any suggestions?

[Tech II]

Since two plugs were bad, were they 1&4, or 2&3? Coils fire those cyclinders in pairs, so if the bad plugs were those pairs, it could be the coil to them.....did you replace all four plugs with A-C/Delco?

Was the module, a new one(OEM)?

How did the "boots" look?

More often than not, if it is not a coil problem, it's a "tower" problem.....the tower or coil housing, is that plastic housing that the coils sit in....

[pontiacfanactic]

Plugs are A/C Delco and coils are in a pot metal or aluminum cover that bolts down on the head. The ICM was one from boneyard. With ICM unplugges engine turns over fine and there is no shaking of the engine then.

[Tech II]

The coils are housed in a plastic "tower".......they are known to have misfire problems.......

[pontiacfanactic]

Replaced ICM and both coil packs along with new plugs. Still have no spark to #3 cylinder. Wet with gas and engine still stumbles to point of rocking it. Noted two light brown spots on inside of white plastic coil housing. Would this cause the misfire? Please respond. Thanks in advance.

[pontiacfanactic]

The spots are in the terminals for the coil to go into.

[thephantom1492]

the spots could be normal, or could be abnormal. hard to say without seeing it.

[Tech II]

Sad to say, the problem could be in the tower and be internal without you seeing it....there are runners in the plastic, that connect the coils to the 4 electrodes of the tower....

[doctorhrdware]

If cylinder 3 is not getting a spark that should also mean that cylinder 2 would also have no spark. That would be very strange that only cylinder 3 is the only one to have no spark. The coils fire all the time. Have you checked cylinder 2 to make sure that it has spark?

[pontiacfanactic]

The boots are new. Pulled all the spark plugs. looks like #4 is the only one good. #1 and #3 wet with gas. #2 black or carbon looking. Spots on white plastic coil housing are rust colored on the same side as the ICM. Do you think it needs replacing? Coils are both brand new.

[thephantom1492]

You seems to have several problems.

First, I'ld start by clearing the flood and carbon...

To clear the flood, there is several ways.
One is to floor the gas and crank. This do not always work.
Another one is to remove the fuel pump fuse, remove the spark plugs, then crank. and of course, since there is no spark plug to block the hole, it will spill out all the fuel out, and the engine will crank weirdly (no compression, so will be easy to turn, so will sound very differently)

Then I'ld make sure that all the plugs are clean, specially the one with carbon deposit.

Ideally, confirm that the spark gap is the right size.

While you have the spark plugs out, write down the model and do a quick check online to be sure that they are actually compatible with your car.

Once the flood is cleared, and the carbon deposit cleaned, and plugs are dry, reassemble, put back the fuel pump fuse if you removed and try it back.

Before trying it back, check the fuel pressure regulator, mainly the vaccum line, to see if there is any gas there.

[pontiacfanactic]

Originally Posted by Tech II

Sad to say, the problem could be in the tower and be internal without you seeing it....there are runners in the plastic, that connect the coils to the 4 electrodes of the tower....

Would this cause the engine to have loss of power when in gear. Sounds like it stumbles when throttled up every so often with an occassional backfire. #4 sparkplug is burning hot leaving some whitish deposits when checked after running. See previous post for condition of other plugs after running. Did spray some carb cleaner in intake while egine was running did improve sound and some running but still lack of power when put into drive and reverse kind of like a tractor sound from engine that put put sound when under load. Does fuel pump failure cause such symptoms? I would think engine wouldn't run at all if it was failing. Please respond. Thanks again.

[thephantom1492]

Fuel pump failure will not cause cylinder to be flooded.
It will cause a lack of fuel due mainly from the pump not running, running eratically, low pressure due to various faults (ex: there is a thing to remove the excess pressure, basically a spring that push on a ball that block a hole. the pressure push on the ball until there is enought force to move it, creating a "leak". A broken spring would be weaker or no pressure at all). Also a broken rubber hose inside the pump assembly could cause a pressure lost, and so on...

A fuel pressure regulator failure could cause flooding, rich running, or even lack of pressure. (They fail open usually, not closed). Also they tend to leak in the vaccum line, causing fuel to be sucked in the intake.

Fuel injectors could be stuck open, doubtfull since you probably have one per cylinder.

Could be a lack of spark due to:
- faulty/wrong kind/wrong gap spark plug
- faulty tower
- faulty coil
- faulty wiring
- faulty ECU
- faulty various sensors.

I'ld be worried about the MAF since you seems to shoot thing around (carb cleaner) that can damage some sensors (like the MAF)

If the MAF if faulty, it can't know how much air get in, so can't give the proper amount of fuel, which can cause flooding.

At this point, you might be better to have the car computer scanned and the live data of several sensors checked.

[pontiacfanactic]

Yahoo it was just the coil housing. Runs great thanks for the advice.