QuestionQUESTION: Howard,
So, to catch you up, My XJ6 after 3 months of body work and paint, needed a distributor cap and rotor to run smoothly, then a coil failed one hot afternoon, but it seemed to be flooding and you gave me specs for the coolant temp sensor last time we communicated. The sensor checked out fine, and on the next time I decided to take the car out, I started it first try, moved it to the driveway, shut it off for a quick wash, and took my wife to dinner. No issues there, and after dinner, it again started on the first try. We drove just next door to do some quick shopping, and on returning to the car, maybe 15 minutes later, it started first try again, ran very badly for 30 seconds and died. I again felt that maybe it was flooded somehow, so waited 15 minutes and tried again. This time, it coughed, and tried to start, but did not. I waited, and waited, trying again periodically, and of course, had not brought any tools or test gauges along. After an hour or so, I began to seriously doubt it was just flooded and started at the beginning of the test procedure, having her open the flap at the throttle, while I listened to the fuel pump (picture this, she in her evening dress, me in my dinner attire) and low and behold, the fuel pump was acting erratically! So, it all came down to the positive lead was loose, the nut was stripped on the post! A passerby offered a set of pliers, and I borrowed a few washers from other non-critical locations to put between the nut and the ring terminal on the post of the + side of the fuel pump and it was running well enough to get home. My goodness. The next day, when the frustration subsided, I heavily soldered new ring terminals on both sides of the pump and crimped them to new ground wire I made, and the factory + lead. I have now taken my car out for a few drives and it is perfect, but my wife will no longer go out with me in my Jaguar. I can't blame her, and I am taking advantage of the the solitude. I am also going to put together a basic tool kit with my test gauges, fuses, and other "oh no" supplies that will stay in the trunk, just in case. Just thought I'd let you know, Have a great holiday!
Thanks,
Michael
ANSWER: I love the series III Jaguar but you are seeing some of its draw backs. I have learned when people say "That is a lovely Jaguar, should I buy one?" I have to tell them. "Only two kinds of people should own an old Jaguar, a Jaguar mechanic and a man who can buy a Jaguar mechanic".
Also, If you want to keep the car you need a back up car. Admittedly I carry a trunk full of spare parts and tools and in my wallet I carry the phone number of my local wrecker service but lately I joined AAA auto club.
By the way your last problem was not a Jaguar problem. The fact that you said the nut was loose on the fuel pump indicates it is an aftermarket pump because all series III Jaguars came with flat spade terminals on the OEM Bosch pump and the wires were flat spade terminals. Only some aftermarket pumps were bolt on terminals including the aftermarket Bosch pump. If it is a "NO name" pump you should consider purchasing a spare to carry with you because the ones with no name on them are noted for a very short life span but they are usually very cheap to buy. (Engel Imports has some) Next up in price is the Bosch aftermarket pump at just under $200. (NAPA) and the OEM may run you $350.+ from Jaguar.
Howard
---------- FOLLOW-UP ----------
QUESTION: Howard,
The Jaguar is not my main car. It is a toy/project I like to work on and take out on evenings and weekends. Of course that last issue was not a Jaguar issue, but I must say this is becoming downright maddening. I have taken my car out on evening drives on a few occasions in the past week or so with no problems as long as I drove continuously and did not shut the car off until I returned to my shop. So, last night, before returning home, I decided to stop and fuel up both tanks after driving for nearly an hour on freeways, boulevards, and even windy back roads. Of course again, after the few moments it took to pump $15 in each tank, it started, ran poorly for a few seconds, and died. I jumped right in to action with a screw driver in the MAF sensor flap and key on, I definitely heard the relay click so I walked back to the trunk and the pump was not running. Remember I said before, I had soldered my wires to the pump, in addition to grinding a shiny clean spot of metal for the ground, and using a crimp-on butt connector on the + wire. I trust this work to be good as I have a pretty good background in electronics repair. Where it gets interesting is that if I shook the pump in its mount just a bit, it would come on, but - I know what you are thinking - I was not tugging the wires - I had tried that. It was actually man-handling the pump within its foam shock mounts that made it come on, but just for a moment. I repeated this several, several times, and every time, it would quit before I could get back up front and turn the key to start! I had a by-stander verify this for me by listening to the pump as I ran for the driver seat. Same bystander pulled me a block to my house, and I was able to coast right in to the shop. An hour later, it starts and runs fine - fuel pump humming nicely. I'm not taking my Jaguar out again until I have another pump, but have you ever seen a hot failure on one of these cheap aftermarket pumps? I can be just about sure that if I had skipped the gas station, I would have gotten home no problem. I love my car, but this is the most confounding thing I have seen yet! No need to repeat test steps, I know them backwards and forwards now, and am sure I have a junk pump, just wondering if you have seen this or known of this happening.
Thanks,
Michael
ANSWER: Yes, I have experienced the exact same thing with the cheap aftermarket pumps. Pump quits and if you wiggle or bump the pump it starts running even with good wire connections. I cut one open to see what failed and I found to my surprise that the pump was well made for a cheap pump. I found that the brushes were sticking in their brush boxes. (thus the shaking or bumping made it run again) The clearances were not enough and the brushes were sticking in their guides. I could not see any method to open a pump up to correct the problem without destroying the pump case and it was not economically possible to make a new case for one.
It is a shame that info could not be relayed to the manufacture as there is no name on any of them. (probably made in China) as it seems to be a "Knock-off" copy of the Bosch pump.
I bought several and use them as a spare to carry in my trunk parts department. I found that they only last a few months at best but as a spare to get you home with, they would be ok.
Bosch does make a aftermarket pump of their own and it is sold by NAPA and is about half of what the OEM Bosch pump is.
I have cut many Bosch pumps apart to see what made them fail and most were trash in the roller cells of the pump not electrical failures. The NAPA aftermarket Bosch pump has a one year warranty so I am not worried using one. I even considered making a shunt with a one way valve system and a switch so if I had a failure out on the road I could just flip to the extra pump.
I may still do that as even if I carry a spare pump it would be a pain to change the pumps along side a road at night in the rain. In the mean time I joined AAA auto club.
Howard
Howard
---------- FOLLOW-UP ----------
QUESTION: Howard,
Ok, my next step is to get a Bosch pump and the one I currently have can be the spare. Do you run a filter in front of your pump? I of course have a fairly new filter in the stock location, but it has always kinda bugged me that there is no filtering device in front of the pump - hence the threat of minute bits of dirt ruining the pump. I also took apart the last one before this, to see how it worked and see what made it fail and found a small bit of grit and although it would spin, it would not move fluid. I was able to straighten the crimping at the outlet end and slide the cartridge out intact, then I attempted re-assembly, but ended up just throwing it in the trash.
Thanks again,
Michael
AnswerI had considered doing that but you have to take into account that the pump moves a large volume of fuel and any restriction would shorten the life of the pump so any filter would need to be very large and with little restriction. There are screens in the tanks but as you already noted trash can get past.
If you notice the existing filter is quit large for a fuel filter and I had planned to run pressure drop tests of that filter to see if it was possible to just add another one like that before the pump but I have yet to run those tests.
The problem with the tests are that running a test of pressure before and after the filter is not accurate because of the fact that on the inlet side you only have 14.x PSI pressure plus the 3.5 lbs that the vapor pressure valve applies. Where the outlet pressure is 30+ to 40+ PSI of system pressure. I guess the volume is the same so maybe the pressure drop may be the same. Another factor may enter into it that the inlet hose and fitting is a larger diameter. We would need the advice of a hydraulics engineer to answer that one.
Howard
