Converter Ballooning (Gears article)

 Converter Pressure Gears article

Mazda6 NOT-P switch fault (Gears article)

 Gears NOT-P article

1998 Dodge Ram 1500 Cranks, No-Start

 This one does engage the starter and the engine spins as it should but the truck doesn't start. The technical term for that is a crank/no start condition. The engine cranking properly means we don't have to consider any starter or battery related issues and can consider those as tested and passed. This is when some might say I think its the fuel pump, or similar guess. When you are the one supposed to find and repair you can't just guess and try that. I don't do checks in a particular order, I work with the truck. It isn't the fuel pump. The fuel pressure is easy to test on this, and within specs. 

We can move on. Just because I have primary fuel pressure in the rail does not show that I have secondary fuel delivery via the fuel injectors which are electrically operated. The quick test for that would be a noid light to let me know if the injectors are getting power and ground signal during cranking. The light simply plugs into the injector connector and will flash as the injector pulse is present if that system is working. 

We have cranking, primary and secondary fuel delivery. We are going to look for secondary ignition (spark) from the coil next. The coil is very easy to access on this truck and we want to look at the connection and ignition coil tower for obvious problems before beginning the spark output test. I see the problem. Rodent damage to the ignition coil wiring harness. 

I repaired the wire damage and we are road ready! Diagnostics are about understanding how the system works and forming a logical testing sequence to gather the information you need as quickly as is possible. There are systems that are very difficult to diagnose due to the complexity of the system as designed and occasionally due to the atypical cause of the problem but the same method will apply, understand the system, test logically. You are actually more looking to put aside what will not be the problem so you can more quickly find what is the problem. I call it the Cat in the Hat method. To paraphrase, the way to find the problem is to find what isn't the problem. 

Cat in the Hat Method

See ya next time! 

Kenny@ggauto.repair

1998 Ford Mustang 3.8 Cooling Fan Operation

 After replacing a failed lower radiator hose and filling the cooling system I wanted to make sure the electric radiator cooling fan was working properly. 

My Alldata service information says the fan should come on at 221F then stop running when it lowers to 200F. I usually run the engine at about 1500 rpm with the car sitting still while watching the conditions are being met. I want to mention that my Ford service information is less precise about the temperature but says the fan should come on when the temperature gauge passes halfway and turn off when it returns to halfway. The half way point being normal for the conditions. I'm bringing that up because that is exactly what the car did. The engine coolant temperature at just past half way was 210F and that is when the fan came on, at returning to half way the fan turned off at 204F. 

A scan tool graphing the data shows the engine was at 176F when the recording began and peaked at 210F. 

. You can see the graph lowering from the 210F to the 204F before it turns off the fan and begins the cycle again. 

The system looks to be working properly. 

Kenny@ggauto.repair

2014 Pathfinder Intermittent No Acceleration

 The complaint was that sometimes after braking and then attempting to accelerate, it would not accelerate. I drove this around all morning and it did do that once and no more. After looking at scan data and memory codes recorded later and never again seeing the problem I parked it outside and was about to call the customer to update her. I happened to look outside at the car and the brake lights were on. I traced the brake light problem to the brake light relay being stuck on. I took the relay apart and the first 3 times I pressed it closed with my fingers, it stuck in closed position. After that, worked fine again. I replaced the relay and case closed because the car is drive by wire and because the relay was sometimes sticking on the ecm was trying to prevent engine run away and not allowing proper acceleration, due to thinking brake was on. 

I have since learned that Nissan has a TSB concerning the problem and is deleting the relay all together, 

Nissan TSB

Kenny@ggauto.repair

Hard Start Ford Glow Plug System Tests (July 2006)

 

Basic O2 Sensor Tech Training (Counterman circa 2006)

 Not sure the date this was published in Counterman Magazine but probably in 2006.

Kenny@ggauto.repair