mopar_padawan24

so i have a 77 pickup with a 360. i bought it mid february and drove it home about 45-50 miles. i couldn't put my foot in it at all or it would die. so its been sitting in my drive way since then. i recently started working on it, doing a tune up. summit has a carb on sale that decided to put on. now i can't get it to fire up.

if i spray starting fluid it'll fire long enough to burn it away. or if i constantly pump the gas it'll kinda run but not idle. i've tuned the carb the best i can. i'm not sure what to check next. i thought timing but i didn't think it would still fire that little bit.

i'm thinking of putting a new fuel pump in but don't wanna waste the money. any help would be appreciated. thanks.

Silverick

I would install a new fuel pump.

78D200

You need to see if you are getting fuel to the carb and spark to the spark plugs. You can pull the fuel line off the carb and have it dump into a bucket. As you crank it over, fuel should come out. There is a test light that you can buy at any decent parts store that will plug in between the spark plug wire and spark plug. Every time it gets spark, you'll see the light come one (pretty cheap tool).

I'd start with that.

Mopar_71

Yep... Sounds like no fuel.
X2 n pulling the fuel line to carb and cranking it over to see if fuel comes out.
Let us know what you find.
Good luck!!

440roadrunner

Could be other things other than the pump, although that is a possibility. You have a service manual?

Here's a link where you can download a couple, they are good to have There's a 72 and 66 car manual, but the fuel pump stuff should be very similar

http://www.forabodiesonly.com/mopar/...al%2C+download

If your carb is connected with clamp on stuff, just get about 6' of fuel hose and a couple extra clamps, as well as a new filter (metal). I recommend EVERYBODY have a vacuum/ pressure gauge, only about 15-25 bucks at most any parts store.

You could have a plugged fuel line, starting with the pickup in the tank, all the way to the pump. There is usually a hose at the tank, another at the pump, and either of these could be kinked/ plugged/ deteriorated/ leaking. The tube from front to rear could have some pinholes and be leaking.

This is where your hose and vacuum ga. come in. If you cannot get the starter to produce fuel, using a hose on the outlet into a bucket, Unhook the inlet to the pump and hook your vacuum ga. to the pump. It should "pull" at least 12" vacuum. If not, replace the pump

If it does, "rig" a hose into a small tank of gas to the inlet, hook up to the carb, and see if it runs. If it does, concentrate on tank/ pickup/ fuel line problems.

READ the shop manual. Lot's of good stuff.

You know how to look for an acellerator pump shot at the carb? If the carb is getting gas, and the thing isn't too gummed up, working the throttle should result in a squirt of gas into the intake.

Another thing you can do ( to check the carb) is unhook/ plug the pump, and "rig" a hose from a small gas can to the carb, starting a siphon. Hang the gas can from a stepladder or the garage overhead. With gas siphoning into the carb it should start and run OK

SIMPLE troubleshooting methods can often save you money.

Or you can just pick some parts, buy 'em and start "throwing parts" at the problem.

lunati318

THe problem does sound like it would be the fuel pump. I just bought one for my truck and it only run 36 dollars. But, if you don't have the money for the test light 72D200 suggested. "no insult some people just aint got the money" Justr put the plug wire near a ground and roll it over to check for fire.

rickyr

I would unhook the fuel line from the carb and put the end in a can or something like that
than turn the engine over and see if it is pumping fuel
if not you will need a new pump

mopar_padawan24

so i got the little spark tester and i got spark. replaced the fuel pump but still not starting. its getting dark here so i'll check the lines tomorrow for leaks. there is a new metal filter in between the tank and the pump and also a new one between the pump and the carb. new plugs, wires, cap and rotor also.

held the choke open and pushed the throttle and watched gas squirt in also. i have a hanyes repair manual also.

78D200

Have you checked the timing at all? Being a 77 is that still points in the dizzy? Have you checked compression?

You need three things to run: fuel, spark and compression. As long as you have three and the timeing on each it correct, the motor should run.

TVLynn

I would check all of the rubber hoses back at the fuel tank. The fuel pump may be sucking air.
Also what you might do is align the timing marks on the crank damper and check the rotor position in relation to # one cyl, make sure it is on compression stroke. If it has a lot of miles the timing chain could be suspect

moparman63

You can begin by removing the line off the fuel pump going to the carburetor. Have someone spin the engine and see if there is a good strong stream of fuel coming out of the pump. If there is not, it is very likely the fuel pump. However, one thing that I always do no matter what when I buy an older vehicle is remove and flush the tank. It is a little work, but years of crud in fuel builds up on the bottom of the tank and can cause mayhem on the fuel system over time. If the pump is bad, that debris could well be what caused it. Even if you discover the pump is bad, replace it and get it running well, you probably will not have fixed the actual cause of the problem. If it was mine, I would remove the tank, drain it, flush it out with dawn dish washing detergent and water....hot water if you have access. Replace all of the rubber hose in the fuel supply line. There won't be a lot. The rubber hose can break down over time and cause even more debris to clog the filter and can even get through to the carburetor. Once you have the tank good and clean, make sure to get all the water out. Having pulled the tank, it would be wise to replace the sending unit with a new one. They are cheap and you will know you have a new one installed when done. That will be a clean tank, new sender, all rubber lines replaced in the fuel supply line and don't forget a new filter. I also recommend flushing the fuel line out with the same soap and water sollution while you have it all apart. Just blow it out good with compressed air. I wouldn't want my new carburetor on there without doing everything as I outlined. You don't want your new carburetor getting messed up.

mopar_padawan24

before i reply i want to thank everyone for the help and ideas. i really appreciate it.


so i lined up the crank to tdc and the rotor matched, both at number one. i would like to clean out the tank but don't really have the time to do that right now. no leaks in the fuel lines. i have replaced a couple when i put new filters in.

here is a short video of what happens when i constantly pump the gas.

http://www.youtube.com/watch?v=IsA_6g_ctyc

Silverick

It sounds like it's trying but, the fuel supply and/or pressure isn't constant. Maybe the cam lobe for the fuel pump has gone flat. I had this happen with a 383 and ended up with an electric fuel pump.

rickyr

Did you ever run the fuel line into a can and turn the engine over to see if it is putting out fuel?

440roadrunner

Look, you need to stop screwin' around and take a logical approach

Go re-read what I posted.

YOU MAY HAVE introduced new problems when you replaced the carb.

Do you have a gasket leak at the carb?

Vacuum leak? did you forget to plug some port, like the PCV port?

Idle? Did you try backing the idle screws way out rich?

================================================== ==

You mentioned "cleaning out the tank." THIS IS NONSENSE. Troubleshoot the problem, and don't worry about the tank until "you get there."

Re--read what I posted.

Go download the manuals I posted and read the section about fuel pump troubleshooting.
================================================== ===

Here's the FIRST next steps I would take
No1, put the old carb back on for now

No2 Get some fuel hose and a small gas can, and "rig" a siphon overhead. Hang the can from the hood latch if you don't have anything else, like joists above in the garage. See if the engine runs OK "off the can."

If that works, attack the pump problem. Run your hose from the can, on the ground, into the inlet of the pump. Run some hose into an empty can and time how long it takes to pump so much gas.

A good pump should pump a quart in 1 minute at idle. It should pull at least 10" of vacuum on a gauge at idle

Dirt? Did you shake out the filter or examine the old carb to see if there was dirt getting into something?

You cannot fix these things by throwing parts at the problem. Actually, sometimes you can, but it is gonna cost you a lot of money.