Aaron81

Car has somwle kinks to work out obviously risk i took buying the half a** running 305 with a clean garaged body. Seeing the previous owner started to try N make power gains on a 305 for no good reason so as im trying to discover why it runs choppy no power im seeing little mods hea tried coolant bypass mod removed all ac components etc... Left some vaccum lines off ive testsd psi in cylinders is good Bank#4 is getting no fuel for some reason. I did new wires today noticed#4 plug was 3/4 left unscrewed Pulled it out and seems dry .
After wires i pulled each wire off dist cap as it was running and #4 made no difference in hesitation ita not functioning i know the rest are cause the idle gets choppy when i remove each wire from dist cap.
#4 Injector is pulsating fine did the screw driver test trick. Tested and Plug gets spark outside of the cylinder head. All in all 119lbs psi in#4 Good external spark but not firing#4 bank?
Car did sit garaged with 5 yr old gas but we put in 15 gallons of 93 octane and injector cleaner runs drives but stumbles with weak power.
I dont know if single plug is bad or if its a cap rotor issue or i injector. Seems to be fuel or one plug?

Tuned Performance

iTrader: (92)

Sounds like you need injectors especially if you have a 89-92 tpi.
They use horrible multec injectors. The choppy running could be from the number 4 cylinder adding air past the o2 and the ecm overcompensating for what it thinks is a lean running condition.

https://www.southbayfuelinjectors.co...fuel-injectors

Aaron81

i did the obd pin a b connection and no codes just code 12 3 times and still code12 after .
Was original 5 speed which i have to put in it .
115 119 psi seem ok for cylinder psi to me its plenty enough life left to run this until i can afford a 5.7 swap.
What else should i check or do besides new injectors. Car sat for 5 years in garage started only a few times each year gas was old but i topped off 15 gallons of 93octane. I havent done any flushes yet . I do believe valve seals are worn slightly light blue smoke at startup and if it idles to long but nevrr when driving and no oil at tail pipes. I tried half bottle rislone ring a seal fix . No improvements yet .
Main issue is what's the must do tune up for the scenario it in which it sat and wasnt ran for some years. Ive put 250 miles on it its a solid motor no noises just bogs for a second at wot and sluggish dont havw that kick down when you mash the pedal.
All i found so far was coolant by pass mod done and ac removed and one vacuum line off .
rest if it is cylinder 4 issue I thought the injectors were ok after hearing a solid tick tick tick from each using a flat head screw driver via Youtube video. Narrowing down to #4 with good spark with the plug outside of the head but no change in idle drop when i take off the dist cap wire for #4 plug. Just lead me to believe plug may be gone totally or no fuel being sprayed.
Thanks for the help Thus far

Tuned Performance

iTrader: (92)

Besides injectors you might want to check your tune-up items. Plugs, wires cap and rotor.
Spraying starter fluid through a small vacuum line like the hvac line on the passengers side plenum. Doing this if the rpm rises you know for sure it’s a fuel issue. The stumble would go away adding fuel. Other wise you might have a bad ignition wire. You could ohm the wires out.

Aaron81

Just pulled the dist to find this thinking this could be every bit of my problemRotor is 1/8 or more gap from cap all looks corroded this would cause alot my symptoms and even if #4 post on dist cap if rotor tab wasnt making a connection it would cause a complete misfire or no fire on cylinder#4. Let alone week spark on all cylinders

Tuned Performance

iTrader: (92)

The air gap looks fine. No carbon tracking. It’s hard to see if the terminal is corroded back far enough to cause a issue or not. It doesn’t look that bad . You should ohm that wire or put on a spark tester on number 4. I can’t recall the exact ohm rating on spark plug wires but I think it’s 1k per foot of wire.
You can compare two wires .

red rock

iTrader: (2)

How much 5 year old gas was in the tank? If it was Ethanol gas left in there for 5 years, the gas was total junk. Adding 15 gallons to rotten gas will only make the gas marginal at best. You probably have a plugged, clogged injector on #4. It wouldn't hurt to take them all out have them cleaned and tested. As for the cap, a new cap and rotor, plugs should be on the to do list.

Tuned Performance

iTrader: (92)

unless you have multec injectors there coils fail so it’s would be good idea to replace them.