TheSamba.com :: View topic

Tue Jul 22, 2014 4:29 pm

I have a '79 bus that has been sitting for quite a few years, it fires when I spray gas into the intake but it wont run.
I am assuming the injectors need pulled and cleaned or replaced.
I was also wondering if I should pull the gas tank because there is gunk in it.
Would it be easier to pull the engine to get to the injectors or is possible to do with out pulling the engine?
Is there anything else that I should clean? I already replaced the fuel lines from the tank to the injection system, with new filter and pump.

I don't know anything about fuel injection but I am willing to learn.
I have a fair amount of experience with carburetors so how hard could fuel injection be :P :lol:

Thanks for any help and info

Tue Jul 22, 2014 4:33 pm

If there's crap in the tank you've got to get it out before proceeding, you can pull the tank with the engine in but after sitting that long it's likely time for a new flywheel seal as well as the pushrods, fan hub and oil cooler seals. The injectors are asy to service in place, new seals under those too.

Tue Jul 22, 2014 6:10 pm

Before getting too involved with the tank removal, have you tried checking to make sure the fuel pump works and the filter is not totally clogged?

With the tank empty, really consider adding gas rated shut of valves between the tank and the fuel filter and the tank and the fuel pressure regulator. Makes it easier in the future to work on.

Tue Jul 22, 2014 6:33 pm

If you have fuel pressure, you might try goosing the injectors with 12V. Some people have reported good luck with doing this. Don't leave the 12V connected across the injectors for long, just momentarily apply it. Use a fused jumper from the battery to supply the 12V and run a dedicated ground wire. You can probably buy a spare injector wiring connector from a local FLAPS or a wrecking yard.

Tue Jul 22, 2014 6:51 pm

Wildthings wrote: If you have fuel pressure, you might try goosing the injectors with 12V. Some people have reported good luck with doing this. Don't leave the 12V connected across the injectors for long, just momentarily apply it. Use a fused jumper from the battery to supply the 12V and run a dedicated ground wire. You can probably buy a spare injector wiring connector from a local FLAPS or a wrecking yard.

Wildthings-
This is to force the injectors to open if stuck from varnish?

Tue Jul 22, 2014 7:07 pm

Lots of good advice so far...

start with basics....

-do you have fuel pressure?
-have you installed a new fuel filter with lines?
-do you have fresh gas?
-check and recheck and check again for vacuum leaks?
-check for injector pulse ?

Then and only then would I start swapping/cleaning/"zapping" injectors and cleaning fuel tanks!

Just went through the same exact thing and it turned out to be a combo for old gas, semi clogged fuel filter and a million littl vacuum leaks.

Tue Jul 22, 2014 8:35 pm

Thanks for all of the advice.
I have replaced the fuel pump with a inline pump (old pump was bad)
I have also replaced the fuel lines from the tank to the engine with new filter.
The shut off valves sound like a good idea, I'll stick some in it.
I ran diesel into the gas tank and let it drain out (with no fuel lines attached).
At first the fuel would barely drip out but after a while it was a full hose of fuel poring out. The fuel was discolored and nasty looking.
Maybe I can just keep running fuel into it and keep trying to wash it out.
I stuck the new gas line (with filter and new fuel pump) into a can of gas but the bus still wouldn't start.

I will probably just try and replace all vacuum lines.
How do I check the injectors for a pulse???

Thanks for all of the advice from everyone,
Hopefully I can get it going soon.

Wed Jul 23, 2014 5:20 am

74 Superbeetle wrote:
How do I check the injectors for a pulse???

Noid light... You can most likely get a single light on amazon or at harbor freight for less then 10 bucks.

Wed Jul 23, 2014 6:48 am

Buy the Bosch one please.

Wed Jul 23, 2014 9:52 am

Would hooking a voltmeter to the wires work? I could just look and see what voltage it is putting out? If not then I will buy a noid light, I was just thinking I already have the voltmeter.

Thanks again for everyone's help and bearing with me, with my first injection experience.

I'm going to get started as soon as I finish the brakes on my bug.

Wed Jul 23, 2014 10:04 am

No. YOU would need the noid light.

Why not just send otu the injectors to www.cruzinperfomance.com and get them cleaned and calibrated for about $100?

Sned the cold start valve also.

Wed Jul 23, 2014 12:16 pm

Ok,

I'll try my luck first with the tips everyone suggested, if I still can't get it then I will pull the injectors and try soaking and cleaning them my self.
Still if I have no luck then I could send them in.

Thu Jul 24, 2014 5:12 am

Any tips for getting the plugs off injectors?
They really seem tight and I don't want to break anything.
Just wondering if there is a secret to getting them off.
Thanks

Thu Jul 24, 2014 7:03 am

Pull straight back witha wiggle if needed.

Thu Jul 24, 2014 9:54 am

74 Superbeetle wrote: Any tips for getting the plugs off injectors?
They really seem tight and I don't want to break anything.
Just wondering if there is a secret to getting them off.
Thanks

You can take a dental pick and pop one side of the retaining spring off. Then when you have the injectors out, lightly file the back side of the nub the clip fits behind at a slight angle to the vertical so the plug will come off easier next time.

Thu Jul 24, 2014 4:52 pm

Got them off, thanks for the tip, I just didn't want to brake anything.

I checked them all with the Noid Light and they all seem to be working.

Thu Jul 24, 2014 6:19 pm

Have you replaced the injectors seals yet?

$5 well spent.

Thu Jul 24, 2014 8:08 pm

Not yet, I'm going to do some work on it and get up a list of stuff I need before I order.
Thanks

Sat Jul 26, 2014 8:46 pm

I tried some different things that everyone suggested and didn't have much luck. I have a temp gas tank set up on it with 2 filters and a electric fuel pump. I tapped the injectors with 12volt and one made a light buzz sound and non of the others didn't seem to do much.
I'm going to pull them this weekend, I figure I'll soak them and try to do a little cleaning on them to see what happens.

Sun Jul 27, 2014 4:28 am

Go through the FI trouble shooting manual available here on TS. Be methodical, and makes notes of test results. A Vacuum gauge, a pressure gauge, and a multi meter are needed. A test light comes in handy. Probe ends and alligator clips for the multi meter are really handy

When I rebuilt my original engine I had some FI issues- double relay not getting power to injectors (the main issue) vacuum valve on air cleaner no good, and AAR not closing (smaller issues, but the FI and vacuum leaks do not play well)