I just got my car back from having the injectors cleaned (the three step fluid process) and I'm still having problems. The CEL goes on and off intermittently, when it comes on, it is accompanied by a very rough idle in park, drive, and neutral. When accelerating, the car is very rough, and there is a noticeable loss in performance. I suppose that I'm going to have to take it in for a diagnostic, but I want to spend as little as possible on this engine, since I'm getting a new one soon Any suggestions?

 

No do a self diagnostic on the ECU http://vbxmaxima.8m.com/ecu.html. Once that is done, then you can go from there. Also how do you know that the engine mechanically is bad? You should have a compression test done to see if the engine itself is working or failing.

 

Ahh, I think that my FSM will tell me about the self diagnostic. I don't think that the engine is bad, but now I think that maybe my spark is bad- causing one or more cylinders to misfire. How much are compression tests, and what would they tell me about my problem?

 

A compression test costs as much as $50 for the compression gauge. Instructions were posted here and I don't feel like typing them out again. Basically a compression test will tell you if your piston rings or cylinders are below standard specifications. For example if you do all 6 cylinders and get around 160-170psi then everything is fine. Now if you get say 110psi in cylinder #5, then add an once of oil and the compression increases to say 160psi, now you have a bad cylinder. In those cases it is either the valves/valve oil guides/seals or the piston rings. Both are expensive to fix if you don't DIY.

 

If the problem is something simple, like plugs or distributor, then I will probably invest in fixing it. If something is wrong internally, then I'll just deal with the biatch. The car has run just fine while I've had it, so I don't see it being a major problem. Of course I could be wrong, and then I'll move ahead with my project faster.