So lately I've been having issues with my ignition. It seemed the longer I drove the more the truck, my 95 GMC Jimmy would misfire. I was getting a map senor low voltage reading code. I was trying to find everything. I was starting to think the spider injector unit was going bad. I've replaced so many things that WERE bad but weren't the cause of this issue. I was thinking the tranny might be going bad. It just seemed that when the truck got warm it would run worse. Like if I drove to the other side of Houston to pick up the kids. By the time I was driving home it would hesitate all over.

So it turns out that today I looked in the engine and noticed a pool of antifreeze at the return line from the heater core. So I went to take the hose off and check it. When I went to use the plyers to take the hose off the fitting. Well the plyers went right into the hose. Turned out that the hose had a leak and it was spraying the coil. The warmer it got the more it would spray and was basically shorting out the coil and ignition module. Since fixing the hose been running fine and no leaking antifreeze (which was the whole reason I was looking in the engine in the first place).

 

Ha cool. Had one do the same thing right into my open air filter before. Sucks you didn't find that to start with

 

Unusual to say the least!

 

How did you not see coolant all over the coil?? Should be extremely noticeable I would think.