Need help fast! 4-barrel carb issue
 

Alright, heres the background information.

I drive a 1989 GTUs. I honestly have no idea how many miles are on the engine or chassis as the cluster isnt origional, the motor isnt origional, and the whole interior has been changed. I have no idea if the engine is a S4 or S5, but it has a 4-barrel double pumper 660CFM holley on it but only 1 of the pumps is hooked up.

I was about to leave a friends house last night after we did a little bit of partying (no drinking involed [honestly] ) and I start my car like normal. It fired right up, sounded normal, revved normal. So I push in the clutch, put it into first, give it a light rev and start to let out the clutch to get it rolling when i hear a pop. Since then, the car hasn't been running right. The tach maxes out at about 4.5k and i have to hold the pedal to the floor for a good 30 seconds for it to reach there. It feels like the car literally has no horsepower. It is very hard to start and I had to turn the idle up so it wouldn't die at stoplights. If I have the idle set any lower than 1200, it'll die at the stoplight.


I popped the hood the day after it happened to take a look at how everything was working. Shut off, everything looked completely in order. A quick run over of the engine showed no issues visually. I started the car and continued to look at it and decided to give it a little bit of throttle via the throttle arm on the carb. I noticed that only one of the jets for the carb was spraying.


I know the symptoms sound like a popped a seal, but I was wondering if a dirty carb could cause me to have great power loss, lumpy idle, lawn mower sound, etc.



Anyone have any ideas?

Thanks in advance.

check the compression by pulling one plug from each rotor housing and then disabling spark. Crank the engine over and you should hear a series of chugs from each rotor. If it doesn't sound right then a seal may be blown. But yes a stuck jet on the carb will cause massive power loss.

Would I want to pull the leading or trailing plug for the comp test?

And I'm new to carb'd setups. How would I disable spark? Pull the wire off the distributor cap as well?

Also, should I cut off the fuel for when I crank the engine



EDIT: I'm just going to mention now, the jet was EXTREMELY clogged. When I pulled on the throttle lever, one of the jets would actually spray. The other would semi-spray but it wasn't in a stream. Their was nowhere near as much gas coming out of the 2nd jet.

If it makes any difference, the jet spraying poorly is for the rear rotor.

leading is better. bigger hole for you to hear the sound. Pull the spark wires off the distributor and if you can disable fuel (not sure how) do that as well.

If the rear rotor jet was clogged it may have gone lean and popped but this is unlikely.

Well, i'm not sure how long its been running with dirty jets. I'm quite poor and was planning on rebuilding the entire carb this weekend for that sole reason of the jet being dirty and not spraying 100% of the time.

And I was just going to use a pair of vice grips to crimp the fuel line connected to the carb. That or go into my hatch and unplug the fuel pump.


For all I know, I've been driving it with 1 rotor running lean for the past month that i've had it. I never really checked anything on the carb besides the accelerator pump. I usually just checked oil and coolant on the car.