engine running on less than 6 cylinders

[Ahlem]

My son's new to him 1993 3.0 automatic isn't running on all 6 cylinders.
The history of the vehicle is unclear but it is clean in general.
We replaced the cap, rotor, wires and plugs. Plugs 1 and 2 were more brown than the others which were normal but at the point they needed replacing. I will stethoscope the injectors I can get at tonight. An independent repair place said there was rust in the gas tank and the fuel filter was full of crap. I drained the gas tank last night and looked at the fuel filter and there weren't any recent wrench markings on it. The gas was clear as could be and didn't smell old. Because the vehicle had been sitting for some time, I suspect there are a couple stuck injectors. On other vehicles with better access to the injectors, a couple taps might sometimes loosen them up. Is there a good way to check the injector electricals? I only have a Haynes manual and would welcome a link to a better one.

 

[szfarc]

Your situation is very similar to mine.
Does your engine running rough, low idle or shaking ?
Try to detach and attach ignition cables one after another from the cap. Try to hear if the engine noise is changing. If the noise will not change, you have fault on this cylinder.
Measure the compression on all of the cylinders. In the worst case (my situation) you will have burned valve.

 

[Ahlem]

Injectors on 2 4 and 6 are clicking happily.
Anyone know of a location where the electrical pulse to 1 3 and 5 can be checked without removing the intake plenum? Also, I suspect this vehicle had a small engine fire as many wires on the passenger side appear to be spliced back together. The main harness from the ECU is partially unwrapped and re-taped with a lot of red butt connectors right at the fire wall. When I pull 1 3 and 5 from the distributor cap there isn't a noticeable difference in how it runs.

 

[Ahlem]

I found a wiring diagram on autozone.com. The fuel injection circuit appears to be intact. Anyone know if an injector can click along normally and not spray? I'm planning to take a compression test tomorrow before I start tearing off the intake to get at the injectors.

 

[Ahlem]

Compression test results were 170 psi across all 6 cylinders.
I ordered some injector O rings and seals and a gasket and will pull the plenum and the injectors. I'm pretty sure there are crudded up injectors.
I'll put the new fuel filter in too.
Any suggestions on injector strategy? We have a diesel place here that services injectors. I could get a couple used ones and see if they can find 6 good ones out of the bunch.

 

[szfarc]

Compression test results were 170 psi across all 6 cylinders.

Good news!

 

[Ahlem]

Clogged injectors x 3. Here are pictures. I'm taking them in to an injector service place. Next question... With this stuff showing up on the injectors and rails, it has to be coming from somewhere. Even though the gas drained clear, and I plan to change the fuel filter, should I drop the tank and take a look in person? How far should I tear apart into these components?

 

[Ahlem]

As I work my way backwards, here is what I found in the Fuel Filter.
Note to any concerned, a 14mm Crows foot on the end of some 3/8 drive ratchet extensions and a u-joint makes fuel filter removal way easier.

 

[nevada]

As I work my way backwards, here is what I found in the Fuel Filter.
Note to any concerned, a 14mm Crows foot on the end of some 3/8 drive ratchet extensions and a u-joint makes fuel filter removal way easier.

dropping the tank and cleaning it is probably the "correct" way.

but, you could just add in an extra filter, and change it often for a few months until all the crud is flushed out.

 

[Ahlem]

I'm pondering whether the gas line is rusted. There isn't any rust on the outside...

 

[fourwd1]

dropping the tank and cleaning it is probably the "correct" way.

but, you could just add in an extra filter, and change it often for a few months until all the crud is flushed out.

That's MY way

 

[Ahlem]

Tonight I cleaned out the fuel rails. Here is a shot of what backwashed out of one side. I got the injectors back all cleaned and flow tested with new O-rings and grommets. I also back flushed the fuel line. Tomorrow it's supposed to be warmer so I anticipate putting the intake all back together and dropping the tank.

 

[mikekfr]

Lookin like you're in the right area....she's gonna run like a dream when you're done.

 

[Ahlem]

Well I had a 34 degree day today and was able to finish putting things back together. I did opt to put in the new fuel filter and see if my motor was fixed. It runs pretty well. I did have to adjust the TPS to resolve a hunting idle issue. We will see if any fuel supply issues pop up and require further action. I had a bit of an issue with my hose labeling and got my tape tabs kind of dirty. I threw a chek engine light and will start another thread if needed. Clean is good when it comes to fuel supply.

 

[Ahlem]

It wanted to come out and play...