I have a '95 Geo Tracker with about 130,000 miles. The other day I pulled out into traffic and had to accelerate rather quickly to match the flow of traffic (a truck twice my size gaining on me from the rear). Soon after that I pulled into the grocery store, made my purchase and went out to drive home. When I started the engine I noticed a cylinder was missing and would not stop. I drove the 2 miles home and did further investigation. I discovered the front cylinder (4 cylinder, 16 valve engine) was missing and that there was positive and negative pressure at the exhaust. Concerned there was an issue, I have not driven it. I did a compression test and found that all cylinders (front including) were about the same. The front to rear are 115 psi, 110 psi, 110 psi and 100 psi at the fire wall. I don’t know what the issue is or could be. Could you give me an idea of what to check out? The positive and NEGATIVE pressure at the exhaust pipe has me concerned. Thank you, Robert
Your either missing spark or fuel in front cyl.
It would seem if it was valve trouble it would backfire some.
Sticking valve? Use a vacuum test gauge to find out. These are the instructions: http://www.autospeed.com.au/cms/A_2393/article.html?popularArticle