running on 5 cylinders

[jsj123]

My 91 appears to be running on 5 cylinders. Down on power, hard to feather clutch and sounds terrible. It runs smoothly above 3K, but I doubt it is running right. I got 29mpg on a 500 mile trip last weekend.

I am not sure if it is fuel or spark. There is no raw fuel smell at idle, and the cat is not glowing (but the cat may be toast will all of my oil burning)

What I am planning on doing is the following:

1. Ohm all of the plug wires
2. Try a different coil
3. Look at all the plugs (what would I see if one is not firing?)

How do I check the injectors for clogged or inoperable?

Is there an easy way to determine which cylinder is the problem?

Thanks for any additional diagnostic advice. When I ran the codes, the balance test did not indicate any problems. I thought I would try it again, maybe get lucky.

--Stephen

 

[VortecGT]

I would start by running the codes and cylinder balance test at http://www.shophoenixproject.com/eec/eec.htm Then smell the plug, if it smells like gas then it is not firing.

 

[CademiaX]

I would start by running the codes

x2

If it was running on 5 cylinders you would most likely have some misfire codes. I had this happen on mine before I did my 3rd 60k, it ran like SHIT even above 3000 RPM.

Maybe the timing belt has slipped slightly, however I think that my cause more severe problems, but you never know.

Might want to check the easy stuff, intake, air filter, maf.. clean it all up and take her for a spin.

gunked up fuel injector? sure there is a code for that as well that would get kicked out.

just my thoughts.

good luck!

 

[the4biddendonut]

I had a similar problem and found that there are 2 different types of connectors for the coil pack on these cars. They look the same, but the alignment tabs are different. If it is the wrong connector, you can just cut the alignment tab off.

 

[frosho]

The DIS is a likely culprit as well...

 

[92plus]

agreed same problem with my 92 DIS was cooked then the fuel pump went the day after

 

[projectSHO89]

The cylinder balance test will pinpoint the weak cylinder(s).

 

[Phoenix]

If it's the DIS , you're running on 4 cyl.

Run the codes.

 

[frosho]

If it's the DIS , you're running on 4 cyl.

Run the codes.

I only had one weak cylinder when my DIS crapped out... Checked it with a timing light too and it was indeed running on 5.