Spark or fuel issue

[620fever]

     Hey guys my truck is turning over but won't start. The motor is an l20b with a weber 32/36 and electronic distributor, I think it's a spark issue. I ruled out the fuel pump and fuel filter, I ran the outlet fuel hose from the fuel pump into a bucket and when I cranked the motor it squirted plenty of fuel. The carb also seems to be feeding fuel as it should, I see fuel as I throttle. I checked for moisture under my distributor cap, didn't see any condensation at all. Swapped new spark plugs in. I had it running once, I used some carb cleaner and it coughed for a bit but after a minute it seemed to be running ok, then I let off the gas to see if it would idle, and it cut out. I did notice my vacuum advance was loose, the screw was lost somehow, I used another screw to temporarily tighten it, it's still a little loose, I'm not sure how big of an effect this would have. I'm not sure what the next step is so any advice would be much appreciated, thanks in advance.

[kelowg]

pull idle jets, check filter on carb inlet (its where hose connects). pull coil wire and crank over, do u have spark?

[datzenmike]

There is no vacuum advance at idle.

 

So it runs but won't idle is that correct?

 

So has this ever worked right, and this is a problem that has just happened??? Or are you starting with this problem???

 

Does this carb have an idle cut solenoid?

Maybe a vacuum leak around the carb base and the adapter plate.

[racerx]

do you spark? 

[620fever]

This is a new problem, it's been running great with both the electronic distributor and the weber for almost a year. I was only able to get it running once since I've been screwing with it, and the one time I was able to get it running the motor shut off when I stopped throttling. The carb doesn't have an idle cutoff solenoid. I should have checked for spark before posting this, I'll check then update.

[EricJB]

If it responded to the carb cleaner it probably has spark. check the idle jet on the primary side. It's a brass screw in the side of the carb body. Is there fuel in the bowl? Check for water in it as well.

[620fever]

I am starting to think this is a spark issue, I pulled off a plug wire and hooked up an old plug, it didn't look to have a spark when I cranked the motor. I reconnected the plug wires and after cranking a few times, it started for a second then shut off (I had used a bit of carb cleaner). Would it make sense for there to be intermittent spark on a ei distributor, what might cause that? Thanks for the replies.

[datzenmike]

I reconnected the plug wires and after cranking a few times, it started for a second then shut off (I had used a bit of carb cleaner).

Look down the carb and pump the gas several times. You should see a strong squirt of fuel into the primary barrel. Does your carb do this???? If not the accelerator pump is not working properly or the carb is out of gas.

 

 

Pour a couple of table spoons of real gas down the carb and try. If it even fires once the spark is there.

 

Is the choke on, on your weber???? You need a choke this time of year.

[620fever]

Got it to start without any carb cleaner this time. Choke is not on the weber, truck has started easy since last spring when I put the weber on, I will hook up the manual choke and see if that helps. I drove the truck around the block, it drives like it's either not getting enough fuel or is not timed correctly. I got the motor warmed up no smoke from the exhaust or anything, then jumped on the gas a bit and it sputtered and wouldn't move much. At idle it wants to die even after it was warmed up. I need to buy a timing gun and accurately time this thing so if nothing else I can rule that out. Thanks again for the help.

[racerx]

^{if you do buy a timing light, buy a dial one, this type has a dial on the back of the gun or get a digital one that has advance.  Spend a little more money and these types of timing light will help in the long run. You may even find one cheap on Cragslist.  Also make sure you have the right pointer and pulley fo L20B.  A lot of our cars have mix match parts and it will mess with your head, specially when you time your engine.}