no spark 4.3l v6 1991, any ideas

[rewdan]

Hi, i have just changed my plugs, cap, rotor, and the bit inside the cap with the red and green stripy wires. I was getting a spark 2 days ago when I grounded a plug and turned the engine over (thunderbolt ignition). Then the ignition fuse blew (15 amp), traced the fault to the bi metal choke on the carb so unplugged the purple wire and the fuse stayed ok and the key worked again. Its hot here (37 deg right now) so I figgure no need for the choke I think. Anyway, no spark at all now, took the coil lead off the distributor and put a spark plug in it and grounded it and turned over the engine but no spark. Noticed there is a purple wire on the coil, is that my problem, some link to the choke pruple wire?
All advice welcome, I am a bit of a DIYer but have a small amount of common sense and want to get my boat going before my wife really gets the hump!

 

[Don S]

Re: no spark 4.3l v6 1991, any ideas

 

[rewdan]

Re: no spark 4.3l v6 1991, any ideas

Thanks Don, I feel like a complete dunse but it was a loose lead from the coil to the distributor, now getting a spark on all 6 but not firing. The boat has been dormant for 2 years whilst I replaced bits and bobs. When I move the throttle I get 2 jets of fuel, one into each barrel but nothing else. I get a bit of a cough if I inject fuel directly into the carb with a syringe whilst turning it over. the boat only had a bit of fuel in it when left 2 years ago. Do you think it could be this, drain it down and put some new petrol in?

 

[rewdan]

Re: no spark 4.3l v6 1991, any ideas

and to reinforce the dunse bit, can any one tell me how to drain the fuel from the tank?

 

[Don S]

Re: no spark 4.3l v6 1991, any ideas

It may very well bad fuel, just buy a cheap auto electric fuel pump and suck the fuel out of the tank. If there is a lot of water in the tank, you may have to remove the fuel pickup tube and hook a copper tube and hose the the pump and suck all the water out of the tank below the fuel pickup.
You may have a mess inside the carb too.
If you flooded the engine while trying to start it, try going to full throttle and hold the choke open while cranking.

 

[rewdan]

Re: no spark 4.3l v6 1991, any ideas

just a bit more info in case anyone needs it, the boat is a 91 searay 170 with 4.3 and alph 1. I have just uncovered the fuel tank under the deck, has a fat tube for filling, a thin tube to the pump and a third tube to somewhere which I am guessing is a vent. There is a round plate with 2 wires on the top, do I just remove this to get the fuel out? Its getting dark here now so I will stop for the night but hope you guys can help.

 

[rewdan]

Re: no spark 4.3l v6 1991, any ideas

Thanks Don, seems we were typing at the same time! How about if I remove the round plate and aqua vac the fuel out! Would really annoy my wife!

 

[rewdan]

Re: no spark 4.3l v6 1991, any ideas

top tip for draining the tank-
due to siesta here in Spain, I had to improvise. Attached a tube to the fuel delivery line but after many mouthfuls of fumes/ petrol I had a eureka moment. Hold the vacuum cleaner over the syphon tube and let it do the sucking. Worked a treat! All drained now.

 

[D Hayden]

Re: no spark 4.3l v6 1991, any ideas

top tip for draining the tank-
due to siesta here in Spain, I had to improvise. Attached a tube to the fuel delivery line but after many mouthfuls of fumes/ petrol I had a eureka moment. Hold the vacuum cleaner over the syphon tube and let it do the sucking. Worked a treat! All drained now.

You were lucky. Here's a video of what can happen when you use a vac to suck gasoline.
http://www.youtube.com/watch?v=Xj5M-nHIKXM&feature=related

The fumes and the sparks in the vac motor make a wonderful jet engine ;^)

Dwight

 

[rewdan]

Re: no spark 4.3l v6 1991, any ideas

ok, maybe it's not such a good idea so don't do it anybody, playing with vacuum cleaners and petrol can ruin your appliances.

That said, I have finally got my engine firing up, that makes it a very happy day for me as it has taken 2 years to get this far. Yep, 2 years...

I took your advice Don, ave it a couple of squirts on the throttle then left it wide open whilst cranking, after a few seconds she fires up and ticks over on around 2 thousand revs. After about 30 seconds of running the oil is up to normal and engine heat is climbing but she wants to stop. Any ideas any one.
There is only a couple of gallons in the tank but it squirts through the carb if I move the throttle. That said, my choke is still disconnected.

 

[kd7isf]

Re: no spark 4.3l v6 1991, any ideas

Sounds like the idle passages are plugged. Probably gonna need to rebuild and clean the carb

 

[rewdan]

Re: no spark 4.3l v6 1991, any ideas

here is a lesson for anyone out there that is as stupid as me. Having stripped the carb down and cleaned it with some weak acid (I don't have compressed air here), all was looking good and I started to rebuild, until I tried to screw the power valve and metering jets back in. I have burnt away the thread so that they just fall into there holes. I can see thread in the holes but it's not enough to screw them in. What a tw*t.
I guess I am in for a new carb now unless anyone has any better ideas. Glue them in?

 

[daydreamer1252]

Re: no spark 4.3l v6 1991, any ideas

rewdan that is a very sad tale.....am sorry that you are faced with that choice....another carb or don't go boating......I would not have thought of using acid and I will not think of it now either....thanks for mentioning it....there is a part (plug??) in the bottom of some common carburetor that is talked about here regularly (maybe a Quadrajet) that is "epoxied" in place and that seems to work for that....but I am skeptical about gluing jets and a power valve in place....the sealing is critical ....there may be enough "thread" left to make sure location is correct...not even sure how critical that may be....someone who has worked on the specific model and can give a better answer.....will be along shortly I am sure.....


But, on the other hand, what do you have to lose???? What you have now is of little value....not heavy enough for an anchor.....


Hope you find a solution that isn't several hundred dollars...

 

[rewdan]

Re: no spark 4.3l v6 1991, any ideas

true, it's very sad but hopefully I have learnt a lesson. Out of interest, does anyone think it would be possible to tap a new thread and sleeve the jet in the same way a spark plug can be repaired? If not then I am going to try a bit of resin around the top of the jets