Over Rev at Start

[ncgdub]

Hello for the first time. I've already learned a bunch about my fuel system by reading through several threads. Great discussions! But, I have a question I can't seem to find....

I have a 1985 Jetta GL, 1.6. It's been sitting for some time because after sitting for a few days it became hard to start. I assumed it was a seal going bad in the IP. But, I finally decided to attack it, found some bad line connections, bad bypass fuel lines, and the pump needed to be primed. I did that installing a clear line on the return side of the IP and sucked until I saw fuel.... Then I loosened a couple of the nuts at a couple of the injectors and cranked for a few seconds - and yep - there was fuel leaking out. So, I tightened them up and went to start it. After about 15 seconds of cranking it fire up! First time in a couple years!

BUT... it started to over rev and I shut it down right away. Then I loosened the injector nuts again just to see if there was too much pressure, but only a very little fuel leaked out, as if should. Then tried again. It fired and since it sounded like it was not in the red (the tach doesn't work until it gets revved up...) I let it idle for a few seconds, but it just kept creeping up toward the red, so I shut it down. In fact, I may have let it get to high... I hope not. By the way, it was smoking like CRAZY! It filled my garage with black smoke within seconds. It seems like it's getting way too much fuel to me.

Oh, also, I took out the two of the injectors, and they don't look great. Could bad injectors just be allowing a ton of fuel in?

Anyway - there's the story. Any thoughts of what to check next? If I let it run, I'm pretty sure it will blow itself up!

Thanks!!
Nathan

[Fatmobile]

Black smoke?
Mouse nest in the air filter?
How long did it sit?

Injector could be pissing.
Clear lines between the injectors, the small ones.

[82vdub]

The inlet vane in the injector pump could be stuck and giving too much fuel as well. By the fact that you can shut it off with the key means that it's not an oil ring and runaway issue. It'll be fuel, injector pump, injector related item.

[ncgdub]

Thanks folks!

It sat for almost two years, but mostly in my garage.
Yes, black smoke - and it sounded like it was a whole lot of "knocking/dieseling." It wasn't pretty....
No air filter at the moment, and no nest...
I've checked, and the lines are clear between injectors. In fact, they are pretty weak and almost rotten and should be replaced.

A stuck inlet vane sounds plausible, which means a rebuild for the IP, correct?

Thanks!
Nathan

[ncgdub]

Oh - do you guys recommend having the injectors cleaned or rebuilt, or should one just buy new ones?

Thanks!
Nathan

[TylerDurden]

Somebody will have to explain to me how a stuck lift vane can cause the HP section to deliver too much fuel.

My guess is the IP governor weights and control collar are sticky - that could cause the inital hard start and the more recent overfueling.

The likelyhood is it needs a cleaning and possibly a rebuild.

I'd try a hail-mary by filling the ip with naptha or Diesel Purge and letting it sit for a few days to dissolve any possible gum from wet veggie or other alt-fuels. Then I'd run it off a coupe quarts of naptha or DP and see how it goes.

If the governor and/or control collar are corroded, it might be time to find a better IP, or rebuild.

[82vdub]

Oops, wrong part of the IP.......

[ncgdub]

Great! That makes sense. I'll try the Diesel purge idea and see how it goes. It would sure be sweet if that cleared it up.

This car is not in the best of shape, so trying cheap and easy things first makes the most sense. If I can get the engine running smoothly, I'll start thinking about all the other little things, and not so little things it needs. On my list is struts, brakes, tires, a windshield, a couple door handles, and probably a few more mechanical issues I don't know about yet. All of the sudden it adds up to the price of one of these things in good shape....

But, first things first.

Thanks all.

[Fatmobile]

Clear lines to and from the pump and between the injectorsare the first thing.
Maybe back the max fuel screw out a little in case the previous owner screwed it in too far.
I'm thinking fuel left over after the burn, from a bad injector but Tyler could be right about the flyweights sticking inward holding the RPMs high. Especially if the pump was sitting dry, and it sounds like some of the fuel could have siphoned back to the tank.

An old '85 Jetta TD had stuck flyweights. It didn't rise RPMs slowly. It was like it was floored.
The flyweights are on a spinning shaft as it spins they fly farther out and push against a lever,.. basically back against your foot.
If they are stuck in, nothing is there to slows the RPMs,.. no governor.

[ncgdub]

Thanks. Your post made me realize that I didn't explain the rise of RPMs well. When I say I let it idle, I meant I didn't put my foot on the pedal. It was exactly like it was floored and jumped up to about 4500rpm (I'm guessing because the tach was bouncing all over), and then started to rise more slowly toward the red - just giving me enough time to shut down.

And, yes, it was probably sitting dry for the last two years - I'm pretty sure I remember checking the lines back then and they were dry - like the fuel had been siphoned back to the tank. I think we may be on the right track.

Thanks all! Time to go buy some diesel purge and turn a wrench or two now... I'll report back.

[Fatmobile]

You'll need a DGK 126 seal set if you remove the top to get to the flyweights.

[ncgdub]

Update:

I have diesel purge in the system now. But, I assume this is a "hail Mary," so where can read about how to get to those flyweights? I know very little about the IP, so it this something that I can work on without removing the pump? Time to educate myself.

Thanks!

[ncgdub]

It worked!!! I came out to try again and it revved up too high, so I shut it down and began to resign myself to real work. But, I had the thought that if the diesel purge had worked at all perhaps I could tap lightly on the IP and poof! That did the trick. It started up and just purred like it has for years.

Now I'll set about fixing lots of other little things.

Thanks for your help!!

[TylerDurden]

WHOOHOOHOOHOOO! Better living through carcinogenic solvents!

We'll call that a win for the team. (But honestly, it mighta just needed the whack. )

OTOH, a good soaking in DP can't do anything but good for an IP.

[ncgdub]

ok. I'm back...

The Jetta has been running great, but the IP has developed a leak at the seal between the main part of the body and the section where the fuel lines exit. Can that seal be changed without a full rebuild of the pump?

And, where can I order parts? Thanks!