Hi. I have a very peculiar problem that has really plagued me for a while now.
This is what it is. I found out very recently that cylinder #3 was not firing (it was a dead cylinder). This problem causes very shaky idle, low idle, and sometimes stalling. I tested it for spark and fuel they both were good, then I was going to test compression, but then I found out that my cylinder was actually still firing, because I tested it again like I did before by taking the spark plug out, and this made the idle bad, meaning that it was working. Pay attention to this part: Whenever I start the car up and let it idle in Park or in Neutral it uses cylinder #3 and idles fine, but whenever I throw it into into any of the gears (D or R) and drive it, it will stop using cylinder #3 altogether!

After this, I found out that my injector resistor box could have gone bad and so I tested it with a multimeter according to the instructions in the Haynes manual. They said to replace it if the proper ohms were not found. The results were that I found no ohms during the test.

So should I go ahead and replace the injector resistor box or are there other causes like wiring or the ECU that I should look into?

Thanks and happy holidays

 

I doubt there's any problem w/ injector resistor box.

More likely a bad distributor cap, rotor or spark plug lead that breaks down when additional load is added.

Suggest checking compression as you originally planned.

good luck

 

I agree with texashonda do a comp. test post numbers also how did you test resister box? Also any aftermkt. parts on the car? sounds like #3 is going away under load can you use a stethoscope to check if the inj. is working

 

I just did the noid test and the compression tests. The noid light cam back positive, the electrical connection to the injector was fine...
The bad news is the compression results...

>>> Compression Results<<<

Cylinder #1: 155 psi, 200 with oil.

Cylinder #2: 128 psi, 160 with oil.

Cylinder #3: 26 (!) psi, 40 with oil.

Cylinder #4: 40 (!) psi. 50 with oil.



What is normal psi, 150? Those last cylinders are screwed! What do I do next!?

 

Those readings mean leaking valves is most likely.

Cylinder head must be pulled, rebuilt, and new head gasket installed. Cylinder head rebuild should include cleaning, leak testing for cracks, replace damaged valves, new stem seals on all valves, reseat all valves, and shave head flat.

good luck

 

That's impossible though because the cylinder head that is on it right now is a rebuilt one and only a year old. Its possible that it was a defective product but I doubt it. The head gasket is only a year old and also the head so they should be fine... How can you be sure that its the cylinder head or gasket?

I can rebuild the cylinder head and replace the gasket if they're bad but I just need to know what tools I need, what parts, and what to do exactly.

How do we know its not the piston rings?

 

A leak down test will help identify the problem. If you go to the ericthecarguy website, there is a video on how to do this test that will help.

 

Compressions that low mean a major leak. Only a valve could leak that rapidly IMO.

Was the head rebuilt when head gasket was replaced?

Tools: typical metric sockets and combination wrenches.

You will need to remove the timing belt which requires a crankshaft restraint tool, two good quality 1/2"x18" breaker bars, 1/2" x 19mm deep impact socket, and a 1-1/4" to 1-1/2" extension pipe of 3 ft to gain extra leverage on the 18" breaker bar. These are necessary to break the very tight bolt holding the crankshaft pulley in place.

Download or purchase a shop manual for your vehicle is essential tool also.

good luck