|
This is a story with a motto: "Donīt hang yourself, get a coat hanger instead"
Year and a half ago my main fuel pump broke down. Replaced. Sometime later the new pump started being noisy. ībout a year ago it became evident that the in-tank pump was very weak or non-functional. Car still running well. Finally I realized I had to do something about it, although the work of extracting the tank assembly made me hesitate. Ordered the full in-tank assembly because I feared breaking the old one when extracting (rusted clamps, tight space, my inexperience etc). But 2 months delivery/backlog in Volvoīs supply line, expected delivery early March.
Couple of days ago car started acting up, losing power, engine shutting down in traffic etc. Same time high-pitched noise of very variable frequency from main pump. Am dependent daily on my car so had to do something immediately.At Volvo they only had the main pump in store, got it, replaced + replaced main gas filter. No bettter. Quickly back into garage, 6 hours of extracting tank assembly cutting hoses, sawing off old rusted clamps etc. and putting it back again. Embarked on this with the hope that some of the problem would be clogged in-tank filter sock. Got out tank assembly in two pieces, scaring the *#it out of me, but managed to put it together, same time finding out that in-tank filter was not plugged. Realized that the little pump would be easy and necessary to replace.
Next day got the little pump from Volvo. On a hunch, after reading FAQs here night before, going back to Volvo I also bought the fuel pressure regulator on the terms I could return it if unused (nice guys at dealers). This time managed to get tank assembly out, replace pump and put it back in in 3 hours. Tested car - it cycled between 500 and 1000 rpm in idle, drove OK up to 4500 rpm, then stuttered at higher rpm on full throttle.
Next morning replaced fuel pressure regulator (took 10 min, easy). Started engine. Despite revving it in neutral to 2-3000 rpm a couple of times it still cycled in idle the first min or two. Drove around the block, car then ran OK, and has done since.
Thoughts/procedural ideas:
1. Was fuel pressure regulator to some small degree faulty all the time, causing overload on pumps? Or was the time of failure just accidental, due to high mileage of car (about 160 k miles). Or was pressure regulator failure due to my not replacing in-tank pump soon enough (I doubt this one since I canīt see how a somewhat less than optimal pressure from pump could damage regulator)
2. Does the computer in this car (ī93 945 turbo) have some "fuzzy logic" with "learning capabilities" keeping it in the same strange idle mode when I restarted after regulator replacement, thereby perpetuating symptoms for a few minutes until I drove it around and came back into idle (the air in the system should in my opinion have been pushed out much before the symptoms vanished). If you replace a regulator it is anyways a good idea to drive the car around the block to let air vent out or computer adjust, before drawing any conlcusions on failure/success of replacement.( I was out of ideas and thought replacement was no improvement and just had to get going; sheer luck I did not despair and take off new regulator).
3. The in tank assembly was tricky getting back in, but the vertical part of it slides upwards, sort of inside the upper inclining part, if pulled. The pulling can be done (Haynes manual has a trick with a match, but I found it easier to actually pull on it with a long finger) if you push your longer fingers into tank hole (no bodily associations :) here, please). This is necessary to get the lower end inside a plastic "insert" in bottom of tank (anti-splash device I guess). Procedure worked if assembly was pushed in with a 45 degrees left direction, pushing as far down as possible, then raising it in an as vertical position as possible, then sticking fingers in pulling the vertical partīs "head" upwards inside tank and sliding the whole thing towards middle of car and then poking it into the anti-splash thingy.
4. A cut-open dry-cleaners style old coat hanger is really useful to keep filler hose pulled away from tank hole to allow pulling out and refit tank assembly. See to that you have one at hand if you plan on going at this. Set coat hanger to pull downwards on filler tube, wrap ends of hanger around sway bar in front of rear axle, to keep the pull on the filler hose. I had remains of a coat hanger in car after previous work on front brakes. The coat hanger has slowly become one of the most useful tools in my toolbox! A good piece of string might also work.
5. I cut electric wires to tank assembly inside left "spare wheel" well, to be able to get slack on cable for pull-out of assembly, but to get any future arcing problems as far away from tank as possible. Simple colour coding, no problem to rejoin.
6. Dead motor indicated infinite resistance when tested with ohm-meter. New motor little/no resistance. 12 V between black and red wire above when running with new motor in place (those two leads supplying in-tank pump motor).
7. At first it was really difficult to figure out a way to get plastic ring around tank hole to turn and come off. BUT: the approx one-foot long crossbar in the cars toolbox that fits into spark-plug/wheel nuts hex tool was perfect to use on the ridges of the ring, hammering away with a plastic mallet on the free end! Ring then turned easily after a little oil spray application.
8. The floor cover behand rear seat comes off if you first take off 3 nuts under spring-loaded "flappers" and then pull hard forwards on the "flappers", the whole thing then slides off flat "hooks" holding it down onto car bottom (took a while to figure out). Last bit easy once you know this little trick, enigmatic before you figure out.
With stainless steel clamps now on all tubes, and with the knowledge above I wouldnīt hesitate going at this thing again, think I could now do it in 2 hours. Good luck to those of you who need to go this way, hope above might be of some general interest.
I almost love my car again. Definitely the coat hanger.
Gustaf
|
