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Hi Paul!
Sorry, I thought I'd responded to your fuel line routing question in your other post; I guess I must have hit the wrong button. Midnight posting is not always such a good idea...
In answer to your question 1: I believe your fuel lines are connected correctly now. Fuel is supplied at high pressure by the pumps to the rear of the fuel rail at all times when the engine is running (pumps ON). The pressure is regulated at the "exit" by the FPR (controlled by manifold vacuum) and any excess fuel is dumped back into the tank through the return line. Observe that the connector at the rear of the fuel rail is a high-pressure threaded type, to handle the high pressure from the pumps; the return is simply a hose and clamp style as the fuel is draining freely back (well O.K. under residual pressure from the rail) but there is no resistance at the other end (tank) i.e. no real pressure to speak of.
It would be very difficult to imagine how things could ever be hooked up "backwards", as the fittings for the fuel and return lines are quite different; the car would not even run if this were the case as any fuel released to the rail by the FPR would immediately drain back to the tank.
Regarding your second question, I think you would get a very limited benefit from the type of cleaning you have described. The scenario would be "hit-and-miss" depending on how the cleaner was distributed among the injectors and how many times they were actuated during your cleaning process, difficult to monitor with any accuracy. I suppose it couldn't hurt, although any cleaner that you DO manage to get through the injectors is going to drain right down the cylinder walls and into the oil pan, perhaps not the most appealing scenario...
Rather, as a preliminary cleaning step I would try a high quality fuel system cleaner added to the fuel tank in liberal amounts, added before fueling to ensure good distribution. Err on the side of a higher proportion of cleaner to fuel, say one bottle for a half-tank of premium gas. Then drive it like you stole it; repeat the cycle for a week or two and see what happens.
The actual concentration of cleaner will be less with this method than with yours but as it is constantly being pumped through the fuel system you are giving everything a bit of a cleaning, not just the injectors. Everything in the system will also be "soaking" in this diluted concentration for as long as you keep the fuel system cleaner in your brick, which may help kick some old deposits loose. This is not the final solution to cleaning your injectors, but I did notice definite improvements after doing this on my 745, although that was probably is worse condition than yours, in the beginning, due to neglect by the previous owner.
The real solution to injector cleaning is to remove them and have them professionally cleaned and balanced. This is a relatively inexpensive process ($25 or so each), and the injectors are quite easy to remove. During this process, the injectors will be ultrasonically cleaned, flow tested and spray-pattern tested. You will get back 4 basically new injectors that should be good for many thousands of miles of trouble-free driving. This will also allow you to replace the injector seals (may be included with the pro cleaning, depends); these little o-rings seal the injectors in the manifold and with age eventually allow a bit of leakage, causing rough running and other problems.
Check it out and give a shout.
Cheers,
--
Scott 'Bricking on Japan time' Night shift is ON
--------1993 945 GLT 74,000--------1973 Suzuki Jimny 'Brute' 61,000--------
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