1.6 IDI bad fuel knock after new IP

[GenericName]

1989 1.6 NA jetta with 35X,XXX miles

Car was running great other then some faulty glow plugs(My DD for about a year) Finally got around to re-wiring the GP system and installing some good GP's, had a new pump and injector lines lying around for a abandoned build so i thought id go ahead and swap out the old for the nice clean new stuff. Get everything back together and set timing at .97 and it fired right up but now its got a really nasty knock that I can only assume is a clogged injector? Id normally go test it with the butt dyno and re-adjust lol but im not comfortable driving it with the amount of noise its making right no.

any thoughts or recommendations on troubleshooting the problem would be much appreciated!

[TylerDurden]

I'd loosen the fitting on one injector line at a time and locate the bad runner, then swap that injector with another to see if the issue moves with the injector. If it does, the injector is the culprit and should be inspected/cleaned/repaired.

If the bad runner does not move when swapping the injector, I'd swap delivery valves and see if the problem moves with the delivery valve. If it does, the valve is the culprit and should be inspected/cleaned/repaired.

If the bad runner does not move when swapping the injector or valve, the issue may be in the head, so checking the valves, lifters, timing etc. is in order.

[GenericName]

Got the fuel knock figured out, I believe they sucked up some sediment when i was troubleshooting the pump off a can. Took all the injectors out and had them cleaned and tested.

The car will start and idle fine but when you give it some throttle it will not rev back down when you let off the pedal. Its a rebuilt pump from {removed by moderator] that I had purchased about a year or so ago, could the governor be hanging up inside the pump? throttle cable and the lever on the pump all seem to be moving smoothly and freely so it makes me think its internal issue with the pump. its for sure not running away because the motor shuts off when i shut off the key and the filter is not saturated with oil.

[sgnimj96]

turn the fuel screw down, Idle up as needed

[greg lousy]

could the governor be hanging up inside the pump?

yes, anything sticking in the governor assembly could cause this. I had a seized control collar that caused an extreme version of what you are describing.

if adjusting the fuel screw doesn't help, getting some diesel purge in there for a while, then running a can or two through the pump may be worth a shot

this is just a thought, but I might also back the idle screw out all the way and move the governor assembly back and forth as far as I can a bit, both running and not.... in case somethings sticking (maybe a piece of that same sediment)

[Fatmobile]

If you have white smoke along with it, there might still be a pissing injector,... even though it doesn't knock anymore.