1990 2.6L - Pinging and Very rough running

I have been down with this problem for over 6 months. I would be enormously grateful if anyone could help me with further advice. :) I have had a very bad pinging problem and rough performance and it won't
idle. this is a 2.6L 4cyl with approx 97k miles. So far I have tried the following based upon much "on line" expert advice to no avaail: I drained the fuel and filled with premium. I used the fuel anti'freeze additiive incase any moisture was in the fuel tank. I did find a bad fuel leak in the fuel cross over line at the fuel filter (near to the fuel tank) I went ahead and changed the fuel filter while I was in that area. (Could some dirt/debris been sucked into the fuel line damaged area and make it into one of the fuel injectors??) I went ahead and rodded out the orife's of the EGR valve down into the engine block with a long fine stiff wire (kept this up for over 1 hour of rodding out). I tried all possible ign timing adjustments. I changed the routine parts inside the the distributor, i.e.: rotor, new cap, all new spark plug wires and new Bosch plugs were installed as well. I installed a new 02 sensor and nothing abnormal appears in the Diagnostic codes at all. I have not changed or checked yet the anti-detonation sensor that is located someplace on the engine block. If it is at fault, I will need to determine some way of testing or by-passing of this sensor. Are there any other tips, tricks or suggestions that you might could have me try? Thanks in advance. I'm running out of possibilities to attempt. ......... Ernie
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I finally solved this problem. The main problem was a blown head gasket and the leak was hard to detect due to being located between the inner cylinder walls of #3 and #4. Also, the fuel pump (inside fuel tank) was defective. I thought I would leave this data here just in case others may have these diobolical symptoms. This 2.6L trooper runs like new now and I thoroughly enjoy owning it.
Ernie

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.