It never ends!

[Uraijit]

Re: It never ends!

Mechanical.

 

[kellydee]

Re: It never ends!

Only a couple things cause a DRY float bowl.Starting at the tank
1:screen on bottom of pick-up tube
2:anti siphon valve
3:water sep filter(probably not,I think would take a lot to PLUG it)
4:Failing fuel pump(check with inline fuel pressure guage.)also,if float bowl is dry,crank it over a couple times and "crack" the line at the carb.If the fuel Sprays(not dribbles)you should have fuel in the bowl as long as the filter at the carb is clean.If not,stuck float.

You should noever have a dry bowl.If it runs at idle only,Could be internal carb probs but dry bowl=one of the above.Sometimes dry bowl,sometimes runs but only at idle,I'd say most likely gunked up carb.That happens when they sit a while with fuel in them.Is there a sight tube on the fuel pump to carb?Should be no fuel in this clear line,if there is ,the pump has internal leak.When the bowl was dry and you cracked the line,did fuel "spray"as if under pressure?

 

[hard-3]

Re: It never ends!

tee a pressure gauge in the line between the pump and the carb inlet. if 7 psi running pump is ok if less then there is a problem in the delivery . pump leaking , suction leak from pump to tank, crap sucking up blocking tank pick-up leak at water seperator if ya got one. generally needle and seat trbl is the float saturates with gas and causes it to pump gas all the time and flood. try running it from a gas can with the pump inlet stuck in it.

 

[Uraijit]

Re: It never ends!

Thanks guys!

Yes, fuel started spraying when I cranked the engine with the line cracked.

Water separator/filter is only a couple of weeks old.

I just pulled the screen off the pickup tube, and I'll see if that makes a difference.

Gonna whack on the carb a couple of times, and see if THAT makes a difference.

A buddy offered to rebuild the carb for me, so I'll probably just end up having him do that for now. At this point, I'm committed to converting to fuel injection.

 

[kellydee]

Re: It never ends!

Careful with the fuel mess.Didn't mean crack then crank.crank to pressure up,then with a rag under it,a quick crack and close again will tell you if its got pressure.Again,this will not tell you if there is ENOUGH pressure or flow,just a quick way to see if you are getting fuel to the carb WHEN YOU HAVE A DRY BOWL.Dry bowl but pressure on the line=stuck float!

Don't "whack" the carb.When the bowl is dry and you suspect a stuck float,LISTEN very closely and "tap" it with a screwdriver handle on top the float bowl.If that frees it you will often hear it drop if it's QUIET.

 

[Uraijit]

Re: It never ends!

There was some residual pressure when I cracked the line. It got a good strong spray when cranking with it cracked.

By "whack", I meant that I was gonna give it gentle love taps, and kind soothing words.

 

[kellydee]

Re: It never ends!

A buddy offered to rebuild the carb for me, so I'll probably just end up having him do that for now. At this point, I'm committed to converting to fuel injection.

Rebuild,good idea.Fuel injection,B.O.A.T.

 

[kellydee]

Re: It never ends!

There was some residual pressure when I cracked the line. It got a good strong spray when cranking with it cracked.

By "whack", I meant that I was gonna give it gentle love taps, and kind soothing words.

OK but,was the bowl dry when you cracked it with resid pressure?

 

[Uraijit]

Re: It never ends!

In my opinion, that's a thousand well spent. The ability to tune it from a laptop is much more appealing to me, than trying to figure out float height with paper gauges, trying to determine the best jets/rods for the elevation I boat at MOST.

I boat normally at about 4500' of elevation. Of course, if I go up to Bear Lake, I'm looking at 6000' of elevation, and I'll just be DUMPING fuel into the lake. Head down to Lake Powell for a week, and I'm at 3500'... Not too big of a difference, as compared to my home lakes, but head down to Lake Mead, and I'm at 1200' of elevation!

I'm thinking the cost of the conversion will pay for itself in fuel savings alone. Forget about the added benefits of more power, and less hassle!

 

[Uraijit]

Re: It never ends!

OK but,was the bowl dry when you cracked it with resid pressure?

As far as I know. I don't really have any way of knowing at what point the bowl stopped being dry.

1) It was dry at first (no spray from accelerator pump).

2) I cranked and cranked.

3) Still dry.

4) Crack line (thinking maybe the fuel pump needs priming).

5) Little bit of fuel comes out.

6) Crank the engine, immediately get spray, and engine immediately starts.

7) Shut the engine down quick, cause fuel spray isn't a good thing.

8) Figure while I've got the wrenches out, why not check the filter on the carb.

9) Pull filter--perfectly clean.

10) Re-assemble, and fire the engine.

11) Idles great.

12) Drive out of the marina at about 1000 RPM (takes about 7 min. to get out of marina).

13) Clear no wake zone, and give it throttle.

14) Engine won't go above 2000 RPM, and takes a while to get there.

15) Try giving it throttle in neutral--engine hesitates, then slowly revs up to 4500 RPM before I cut throttle.

16) Checked prop, to make sure there wasn't something wrapped around it.

17) Try driving for a few more min. to see if it will correct itself.

18) Give up, drive back to marina.

19) Pulling into dock, go to give it a little reverse to slow the boat.

20) Boat dies, but immediately restarts.

21) Kill boat, go get trailer.

22) Boat fires for the wife, she drives it onto the trailer.

23) Drive home in disgust.

 

[kellydee]

Re: It never ends!

I'd check the fuel pressure as someone said earlier to see if i wanted to replace it WHILE I WAS REBUILDING THAT GUNKED UP CARB.

 

[Uraijit]

Re: It never ends!

I'd check the fuel pressure as someone said earlier to see if i wanted to replace it WHILE I WAS REBUILDING THAT GUNKED UP CARB.

Aye, planning on doing that as well.

Gonna go put it in the water this evening, and check the fuel pressure, and give the afore-mentioned "whacks" to the carb...

Summer's already darn near over, and this thing's only run right (if you don't count the oil gushing out the side of the oil pan as "not running right") for about 2 hours total!

I'm gonna get this thing working for the rest of the season, and put the EFI in over the fall, so it's ready to go come spring time...

 

[Bondo]

Re: It never ends!

since it's a Q-Jet, and I've never touched a Q-jet.

Ayuh,....

It sounds to Me, that you'd better get Crackin' if you're going to get that EFI goin',.....

Otherwise,..... You need a Carb..........

 

[Uraijit]

Re: It never ends!

Your lack of confidence is completely underwhelming...

Like I said in a previous post, a buddy has offered to do the rebuild on the carb for me.

The EFI is the long-term solution. The carb is just a band aid fix to get through the rest of the summer.

Don't worry though, I'm already hard at work on the EFI side of things...

Already building an ALDL cable... Real-time data feeds, and data-logging! Holy underwear batman!

 

[ziggy]

Re: It never ends!

The carb is just a band aid fix to get through the rest of the summer.

it worked right when it was new. why can't it work right now? ya do that efi thing with a fuel delievery issue. it won't work right either.

Gonna go put it in the water this evening, and check the fuel pressure

ya don't have to put it in the water to check the fuel pressure. just t in your fuel pressure gage between the fuel pump and the carb.
yer carb. may well need some help. but if ya ain't feeding it.... well, ya get the idea....
don't be scared of that carb. so it's got a lotta pieces. take pics and go slow. clean it up proper, set it up proper. with the paper gages or what ever ya have. give it a try.... ya might be surprised..... i ain't rebuilt a qjet in a long time. but i have been successful with a rebuild.... i'm sure others have been too. so it can be done......

ya might give this thread a look too... i think i would be....

http://forums.iboats.com/showthread.php?t=167561

 

[Uraijit]

Re: It never ends!

Well, I put it on the water, to test the fuel pump and try thumping the carb. I don't have a water hose at my house, and my friend who lets me use his, is out of town...

I didn't have a T fitting for the fuel gauge, but I did have enough fuel in the carbs to run the engine for 30 seconds, with the line pulled off the pump.

Couldn't get the thing to do anything more than idle at 600RPM.

I got 4.5 PSI at the pump. manual says 5.25-6.5 PSI at 1800 RPM. No idea what that means for my pressures at 600RPM...

Is this thing a turd, or what?

 

[MikDee]

Re: It never ends!

Have you checked your fuel tank vent, you can run it without the cap temporarily. Or, maybe the fuel line is collapsing inside? By the way, I happen to like Qjets, they're a well proven good basic carb, (I didn't always feel this way, but I've come to know them well) and they're not hard to work on! or figure out how everything works. The main items to check as well as clean jets, & float level, are how the accelerator pump, primary power valve, & secondary butterflys are working. Shoot, it might be something as simple as having debri clogging up the fuel passage after the in carb filter, before the needle valve on the float.

 

[Uraijit]

Re: It never ends!

Yup, checked the fuel tank vent.

Let me clarify, I don't have anything against Q-Jets specifically, I just prefer fuel injection over carbs. I'm not familiar with Q-Jets. In fact, the only carbs I've rebuilt were motorcycle carbs (4 at a time! No fun).

Fuel injection is just better in every aspect--easier to deal with, more fuel efficient, and gives you better startup, more power, and more versatility (Ie: being able to boat at 6000' of elevation one week, and then at 1200' of elevation the next, with no adjustments, or dumping tons of $4 fuel into the lake). It's easier to diagnose, easier to tune, and you don't have to worry about bad gas sitting in a bowl and vulcanizing, ruining a whole week+ of boating...

Like I said, I'm fully committed to doing this conversion. I've already bought most of the parts.

 

[JustJason]

Re: It never ends!

It's easier to diagnose

hehehe.... carefull with that one
Its not always so easy.......

 

[hard-3]

Re: It never ends!

try bypassing the fuel tank- lines and water seperator. get a gas can and hook it up to the fuel pump inlet and run it. a clean outboard tank would be better, but a 2 gal gas can will suffice as a temporary tool. ya need to figure out if its a delivery issue and/or a carb issue. Talk to the guys at the local chevy dealer parts counter and see if they recommend anyone to ya to rebuild the q-jet. Chevy used them for years ,very reliable, on most high performance and heavy truck applications. check with the vo-tech school and see if they might rebuild it for ya. lots of options out there. The best option of course is to get a bucket of carb cleaner, a rebuild kit and do-it-yourself. Believe it or not there is no magic in that chunk of aluminum. Just read the instructions, clean it good, blow it out and put it back together with the new kit.