Monday Lunch-time; I started the truck, noticed the rough idle and the MIL (Malfunction Indicator Light) (Check Engine Light) was on. I shut the engine off and grabbed the code scanner tool that Dave had given to me as a present a couple of years ago. There was a code in the ECM - P0204.
I left the code in the ECM and drove over to McD's for lunch, while driving, when I depressed the accelerator pedal to call for more power the truck shuddered and got rougher, the MIL began to blink. I backed off the throttle and the light stopped blinking. When I got to McD's, about a mile from the apartment, I hooked up the code scanner again and saw that there was a second code - P0304. I got lunch and posted to FB about the two codes.
Dave looked up the codes on Google and replied to my post saying that the P0304 was a cylinder misfire - cyl#4. the P0204 was an issue with The Injector Circuit - cyl#4. Neither issue would be pleasant to trouble shoot in the rain. I resolved to try re-seating the wiring to the injector and the #4 ignition coil when I had finished eating. trying to re-seat the connectors did not fix the issues.
When I got home I logged into my AllDataDIY.com subscription and researched the DTC (diagnostic trouble codes) and printed out about a dozen pages of procedures that I would try when the weather improved.
A day or so passed and lunchtime rolled around and I headed outside with the print-outs and my DVM and a low-voltage test light figuring that I could poke around a little, non-destructively, and see if I could get an idea of how big a mess these issues were.
First test, remove the connector from the injector and test for voltage between ground and pin-blah of the connector, with the ignition key turned to on. - OK.
figured out how to remove the connector from injector #4 without breaking anything, set my meter for DCvolts, connected one probe to a ground, turned on the key and probed the connector with the other lead from the meter... nothing, no voltage reading.
checked that the meter could see battery voltage; check,
checked the key was on; check,
tried the other pin in the connector; nothing.
re-read the instructions - I had missed the part where they said to use the "scan-tool" and enable the injector relay. Ah... this is not going to go anywhere fast! I have no dealer/mechanic-class "scan-tool" and I'm not going to ask around to try and borrow one.
So, dejected I packed up my test gear, put the connector back on the injector, went inside and called Dave to get the name of the place our mechanic was working.
We took the truck over this morning and around 3:30 I got a call from the receptionist at the service center saying...
[Yay!] got a call from the service station saying that Howard had identified the injector issue as a broken wire and he was tracing the wire to see where it was broken and he would try to have the truck done before COB today.
I asked the caller to thank Howard and tell him to not 'kill himself' trying to get the truck finished today, that I need it before COB Tuesday and to please change the plugs - all 16 of them.
I didn't ask the cost of either the injector trouble-shoot & repair or the spark plug replacement. Both are needed and are likely within budget!
So I was lucky; the problem could have been caused by any number of things, several medium to high cost items; injector(s), ECM, engine wiring harness; a couple of low cost items; cutoff relay, fuse.
Instead it was the lowest parts cost, with a medium to high labor cost, a broken wire that needed to be traced and the open identified.
I'm quite happy paying for Howard's time!
I'm very glad that we were able to track him down and get the truck looked at!
I'll post more after I get the truck back and pay the bill.