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88 caprice carb 305 engin problems

 
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DougP10 DougP10
New User | Posts: 1 | Joined: 05/17
Posted: 05/10/17
05:10 PM

Following a starter failure and replacement. Car would start but with in a minute or less run crappy and fail.  ECM light dose not light with ignition switch, fuse is ok, replaced ECM computer no change. Rebuilt the carb a few years back seems to be working the inner solenoid/pump? Fuel is there.  Is there some fusible link to ECM?
where to next?  Confused.  

Just Try It1 Just Try It1
Moderator | Posts: 2121 | Joined: 08/14
Posted: 05/10/17
07:13 PM

with a carb.. do you have a mechanical fuel pump.

install a long loop of fuel hose between the fuel tube coming out of the frame and the pump inlet. once you get the long loop of fuel line installed.. chop into it and install a 1990 ford ranger fuel filter.. you will need clamps but the hose will push over the ridges on the filter .

this is one installation before i got a ranger fuel filter bracket for it.

Dx9hfmq

here is one on a ford  

Rbohc20

why... because i have been fighting sediment in the fuel pump check valves since 1983.

the next step is to disable the ignition system.  using a wrench to hold the big filter nut while you loosen the tube nut on the fuel line at the carb..  this can cause issues hooking them back up.. .. but i stick a piece of hose over that line end and then shove the open end of the hose into a clean clear plastic bottle.  i get somebody to crank the engine for 15 seconds.. i do that 3 times..  this flushes the fuel pump check valves and diaphragm cavity.

please use extreme care hooking the inverted flair line back up to the carb.. i usually have the carb loose when i hook them up..  so i can thread the tube nut in all the way before even putting  wrench on it..

you do have a second choice...

get the engine running..  use a pair of long long nose pliers to squeeze shut the fuel hose between the new filter and the fuel injet. with one hand holding the pliers closed the other hand taking the throttle to around 1800 to 2000 rpms. when the carb runs out of fuel and the engine starts to die.. release the pliers.  the fuel clean fuel will surge thru the fuel pump and wide open needle and seat..  do this 2 or 3 times..

this should cure your problem.. it has for so many of my friends..

if the fuel pump check valves are held part way open with sediment.  you won't have enough suction created by the pump to pull fuel up from the tank..   you also won't be keeping close to 5 pounds of pressure in the line to the carb.  when you shut the engine off.  the fuel drains back to the tank.. so the carb is low on fuel when you start it cold.. the fuel pump because of the sediment cannot pull fuel up from the tank before the carb runs out of gas.  so you end up cranking and pumping for a minute or two to get gas back up to the carb.

do you happen to have a DWELL Meter..

can you see a green wire with a green connector on it near the passenger side of the carb..

set the dwell meter to six cylinder scale.. this is what the manual was written with..  at idle you should have 28 to 35 degrees of dwell warmed up.  bring the engine speed up to about 2500 rpms and you should have 25 to 45 degrees of dwell.  this shows your carb is working..

don't try to adjust the carb without instructions.  these are some tricky carbs.. i know as i used to do them weekly.  

Just Try It1 Just Try It1
Moderator | Posts: 2121 | Joined: 08/14
Posted: 05/10/17
07:16 PM

you may want to also stick a big strong magnet to the bottom of your fuel tank. to attract the sediment to it.
https://www.harborfreight.com/66mm-round-magnet-96650.html

Description
This extremely versatile round magnet is rated up to 95 lb. for a variety of applications around the home, shop, office or garage  

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