bench cleaning fuel rail/injectors

[wbsterritt]

Greetings to all! A brief history is in order I believe. 1983 Fiat Spider(Pinin) with 14K mi. Car sat for ten(10) years in a salvage yard with gas in the tank(fuel pump removed-bad one in the trunk) with fuel feed line "shut off" with a 3/8" ratchet handle stuck into it. After getting the engine to "bark" with starting fluid, I hurridly (BIG MISTAKE) installed a new fuel pump and proceeded to kill the new pump using the existing bad gas. Have since relined the fuel tank. Now, knowing that the whole system is probably in need of a good cleaning, I have since removed the fuel rail/injectors/regulator and would like to try "bench cleaning" it. I'm pretty confident that the injectors aren't that bad (14Kmi.), and along with the fact that I'm so frugle(cheap), I'm planning on just trying to clean the system myself. The questions I have are this(to begin with)-WHAT IS A GOOD CLEANING SOLVENT FOR THE FUEL RAIL/INJECTORS, AND ALSO, DO THE INJECTORS FIRE WITH 12V OR SOMETHING LESS THAN 12V? I plan on applying vacuum to the fuel feed line, plugging the return line, and drawing the cleaning solvent backwards through the injectors into my hand-held vacuum pump by firing the injectors one at as time. Does anyone see any problems with this line of thought? I also have electrical issues with the car but will attack those at a later time and in a different forum. Thanks to all in advance.

[billstyer]

I used 12V when I checked mine & it didn't seem to do any harm. I would try carburator cleaner myself - somebody else might have a better idea. Good luck!
Bill

[So Cal Mark]

12v is okay and we have used carb cleaner. Try pulsing them on and off while pressurizing them with compressed air

[124cso]

I went thru this a few months ago, when car develloped a sudden 2 cylinder miss. Turned out to be an injector problem but in the process, all sorts of things investigated and discovered.
The local Bosch Diesel injection place offered to test and ultrasonically clean injectors for $15 each. Is it worth trying it yourself ?
I'd suggest replacing all the fuel supply hoses. New hose rated at 10 bar cost me $3 something a foot.
Probably worth replacing the filter too. If there was water (from condensation) in the tank, it could be sitting in the paper element (that's all there is in those aluminuim filters).

You mention you "relined " the tank ??? do you mean you used a sloshing compound / tank seal / POR type product ? I considered this as I had pinhole rust in the tank floor caused by either water in the petrol or condensation from sitting fairly empty. The FI tanks are well baffled (unlike the carby tanks I have seen) and you need a remote camera to see the pickup but it has a very guase filter.
I decided that if slushing compound would fill my rust pinholes, it would well and truly seal up the pick-up filter. I found myself another tank.

[wbsterritt]

Thanks for the input guys! One main reason I don't want to send the injectors out to be cleaned is, because the way I understand it, the cleaning company will want just the injectors themselves and not the whole fuel rail and all. Is that true? If that's true then I really don't want to cut off the attaching crimped-on hoses-I would like to keep everything on this car as original as possible. I failed to mention that I already have indeed change the fuel filter-good idea. As far as changing out the fuel feed lines, the jury is still out on that one. While I had the tank out I douched out the lines real well with some carb cleaner till it came out clean. Boy you got me thinking now about the pick-up in the tank though. Never gave it a thought. Yes, I did use a tank liner kit, but not POR, something off the shelf from a CarQuest store. I guess what I'll do now is do some sort of crude flow test when I get the system back together to see if I think it's going to be a problem. May indeed have to find a new tank ultimately.

[124cso]

I was only thinking of the 10" or so of fuel line under the bonnet, from the steel supply tube, up to the fuel rail. That is the piece of line that could be affected by engine bay heat.
The return line is not really that much of an issue as any crap comimg off the inside is sent to the tank (unless it is leaking of course).
Personally, I would say take as little as possible to any repair outfit - LESS FOR THEM TO LOSE. They'd probably just cut the hoses off anyway ( especially if you asked them not to). If you have blockages or hose deteriation, the 4x3" of hose from the rail to injectors should go too. Age and heat is what gets to fuel lines, along with the modern additives they keep putting in the crap fuel we get sold.
I have been told by someone in the know-quote- "avoid this biofuel petrol like the plague, it F**ks everything !"

[wbsterritt]

I have now-albiet, not very scientifically-bench tested my fuel injectors and cold start valve. What I have noticed is that the cold start valve sprays a nice conical shaped stream whereas the injectors themselves are more straight streamed-is this normal? BTW, two of the injectors would not trigger electrically unti I rapped on them with a wooden file handle. Came right back to life!

[majicwrench]

The cold start valve will spray a wider pattern.
I clean injectors with carb cleaner, compressed air, and 12v. Blowing back thru injector works wonders. I suspect that the injector winding would fail if left energized too long, so I use a push button switch and just momentarily open injector. Safety glasses, fire extinguisher.
The injector pintle were just stuck on those you had to rap on. Clean em.

[wbsterritt]

Fuel rail is back into car. Everything went well. Question now is whether 37 PSI is an acceptable fuel pressure or not. I'm seeing the specs as being around 43 +/- 3 PSI. Close, but no cigar! Is this lower than spec pressure going to cause any issues? Fuel feed and return lines are totally clear back to the tank. Possibly a somewhat clogged fuel pick-up in the newly relined tank? Is it worth the cost to try a new fuel pressure regulator?

[majicwrench]

37lbs probably OK. I assume this is with everything hooked up and engine off?? Where are you tapping into to get the pressure reading??
You can quickly pinch off the return line past the regulator and see if the pressure goes up. It should go up. Try it and see what it goes up to.
I would bet fuel pickup not causing the slightly low pressure.
I would not buy a regulator till you pinch off and see what pump can produce.

[wbsterritt]

Finally heard the engine run for the first time last night!!! Fuel pressure does not seem to be a problem. I tied into the system right at the cold start valve. I powered up the fuel pump directly to get my readings. I finally slept like a baby last night knowing that I didn't buy just a big boat anchor! Now fixing up the fun stuff can begin. BTW, the fuel injectors only draw +/- 2.5 volts to fire.

[majicwrench]

Glad you got 'er going!

"Draw" is term relating to amperage, not voltage.
Keith

[wbsterritt]

I stand corrected-the fuel injectors take +/- 2.5 V in order to fire. Took the car out on Father's Day for my first drive with it! Awsomely fun car to drive! Thanks to all for your interest.