Misfire Codes + No Start = Failed Fuel Pump
#1
04-11-2013, 09:53 PM
Misfire Codes + No Start = Failed Fuel Pump
I thought I would relay my story, with the hope of helping someone else, just as I’ve been helped by the many other contributions on this site.
After a happy Sunday’s driving, I returned home and left the car in the driveway for a wash before putting it away in the garage. After no more than an hour or so, I tried to start the car and was rewarded only with the barest running, a stumbling poor idle with no response to the gas. Pumping the gas pedal had no effect, and of course as soon as I shifted into gear to try to climb the slight upwards grade into the garage the engine died. Indeed, after a couple of unrewarding tries, I ended up about 6 feet further down the drive away from my garage sanctuary where I knew the car would have to sit while I sorted out the problem.
I thought of all that I have read on this forum, from cylinder washing, to pump failure, to ECM repair and mentally started a checklist of things to check. First action was to pull out my trusty ELM module and Torque application on my phone, to find codes P0301 through P0308, with P1316 thrown in for good measure. Misfire on ALL cylinders? Since it was already dark, I started with the battery and pulled the negative lead, to carefully touch it to the positive to reset all the electronics, sometimes called “returning them to a known state”. No joy, it still refused to catch.
Since in the previous couple of months I had experienced two other non-starts, one due to a clearly depleted battery, and the other suspiciously like this very event (multiple misfire codes, but cleared with an electronics reset), I decided I needed a new battery anyway so went and bought one from the nearest O’Reilly’s. Having eliminated a frequently named cause of odd Jaguar behavior, I was still thinking of the clean sweep of misfire codes as a low voltage condition. But that wasn’t it.
The next morning before going to work, I tried to start it again after simply removing and resetting relays for the ECM and fuel pump, and checking all the fuses in sight.
A check of the Schrader valve on the fuel rail gave no spray of pressurized fuel, not even a sigh. OK, that was a clue, so I returned to the boot and started removing the decorative covers, and reviewed in detail the schematics of the pump circuit. I really didn’t want to have to deal with removing the tank, which was currently very, very full.
But sure enough, with multimeter and a 12V indicator lamp on the end of a couple of alligator clips, I soon found the ECM was doing its thing, the relay was making contact energetically, and the connections were clean and solid up as far as I could reach just short of the upper part of the tank. The pump was shot.
I called my chosen independent shop, and decided the quoted price was well worth my avoiding the task of removing and replacing the tank, and a tow was quickly arranged under my friendly insurance carrier’s policy. A day later I had my car back again, driving nicely with a new fuel pump and fresh battery too.
Why do I relate my story? In my review of the forum, although I didn’t comb through it down to every detail, I didn’t find any other connection between the misfire codes and pump failure. I was hoping it was an ECM fault or other electrical gremlin, because I could imagine removing and replacing that myself and sending it for repair. But the tank was another matter. So if you suddenly find yourself with a bunch of misfire codes on what was an otherwise good running engine, you might have a look at the fuel system first.
Steve
After a happy Sunday’s driving, I returned home and left the car in the driveway for a wash before putting it away in the garage. After no more than an hour or so, I tried to start the car and was rewarded only with the barest running, a stumbling poor idle with no response to the gas. Pumping the gas pedal had no effect, and of course as soon as I shifted into gear to try to climb the slight upwards grade into the garage the engine died. Indeed, after a couple of unrewarding tries, I ended up about 6 feet further down the drive away from my garage sanctuary where I knew the car would have to sit while I sorted out the problem.
I thought of all that I have read on this forum, from cylinder washing, to pump failure, to ECM repair and mentally started a checklist of things to check. First action was to pull out my trusty ELM module and Torque application on my phone, to find codes P0301 through P0308, with P1316 thrown in for good measure. Misfire on ALL cylinders? Since it was already dark, I started with the battery and pulled the negative lead, to carefully touch it to the positive to reset all the electronics, sometimes called “returning them to a known state”. No joy, it still refused to catch.
Since in the previous couple of months I had experienced two other non-starts, one due to a clearly depleted battery, and the other suspiciously like this very event (multiple misfire codes, but cleared with an electronics reset), I decided I needed a new battery anyway so went and bought one from the nearest O’Reilly’s. Having eliminated a frequently named cause of odd Jaguar behavior, I was still thinking of the clean sweep of misfire codes as a low voltage condition. But that wasn’t it.
The next morning before going to work, I tried to start it again after simply removing and resetting relays for the ECM and fuel pump, and checking all the fuses in sight.
A check of the Schrader valve on the fuel rail gave no spray of pressurized fuel, not even a sigh. OK, that was a clue, so I returned to the boot and started removing the decorative covers, and reviewed in detail the schematics of the pump circuit. I really didn’t want to have to deal with removing the tank, which was currently very, very full.
But sure enough, with multimeter and a 12V indicator lamp on the end of a couple of alligator clips, I soon found the ECM was doing its thing, the relay was making contact energetically, and the connections were clean and solid up as far as I could reach just short of the upper part of the tank. The pump was shot.
I called my chosen independent shop, and decided the quoted price was well worth my avoiding the task of removing and replacing the tank, and a tow was quickly arranged under my friendly insurance carrier’s policy. A day later I had my car back again, driving nicely with a new fuel pump and fresh battery too.
Why do I relate my story? In my review of the forum, although I didn’t comb through it down to every detail, I didn’t find any other connection between the misfire codes and pump failure. I was hoping it was an ECM fault or other electrical gremlin, because I could imagine removing and replacing that myself and sending it for repair. But the tank was another matter. So if you suddenly find yourself with a bunch of misfire codes on what was an otherwise good running engine, you might have a look at the fuel system first.
Steve
Thread
Thread Starter
Forum
Replies
Last Post
Charlene n John
XJ6 & XJ12 Series I, II & III
9
09-28-2015 06:01 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)