VN V8 timing

[Asho88]

Kinking*

[Vrv8hz]

Blocked injectors? Maybe you have pressure?
I've had multiple 304s with seized injectors that sat a few years.
Did you definately have injector pulse? Checked with a noid or something similar?
Can you hot wire the fuel pump relay and listen if fuel is returning to the tank?

[Asho88]

I had one jammed open the others had no fuel on the plugs. Yeah I checked with a test light can definitely see they’re pulsing. Yeah that’s what I’ve been doing to run it longer to attempt to build pressure. Yeah sounds like fuel is running into the tank though kinda plays tricks cause it should be running into the surge pot though if I can hear it must be pretty decent flow to the tank via return.

[vlad01]

The injectors do get blocked/stuck from the residual fuel oxidizing, breaking down and turning into varnish. Clean fuel doesn't dissolve that stuff, sometimes the pintle breaks free and they get going but they flow badly for a long time due to the stubborn varnish. I haven't tried this myself yet, but I know general purpose thinner dissolves that stuff pretty easily. So if you have stuck/blocked injectors from commonly sitting for years, take them out, whip them backwards at arms length several times (don't let go of them! and make sure line of aim is clear of injector and it's fuel/gunk) the g-force will fling all the old fuel out of them, dribble some thinners into them until they are full, let them sit for good while, repeat as needed. It should in theory dissolve out most of the gunk and at least soften any remaining that once the injectors are run it should free up and blow out remaining crap and clear up quicker.

[antus]

I think I have this problem on one of my cars. Was planning to put them in an ultrasonic bath with petrol in the near future, might do it with thinners instead now.

[vlad01]

I prefer to use used injectors and get them going that way than to have them serviced with the typical ultrasonic cleaning. The main reason is all injectors I have had serviced this way weep fuel after where previously they didn't. Like literally 100% of them fail in this same way after a professional service in my personal experience. So that results in the car flooding and hard starting when sitting for 15-30min after being hot and I jump back in.

My hypothesis is the ultrasonic waves could be causing the pintle and seat to erode or pit, either from cavitation bubbles or the pintle and seat violently pounding together at multi Khz repetition. The result is they just slowly dribble at the end. I feel like a failure analysis after ultrasonic cleaning and a before cleaning under a microscope, possibly under an electron microscope would reveal all if anyone has the time and means to do so.

When I need fresh and good injectors, I look to what The1 has or get something genuine and new that suits my needs, send them up to him for the data generation. Once I have done this with a few common injectors, I can keep buying the same ones if available and I have the data for them.

Note that genuine new injectors from anything is hella expensive, so not something I have done much of. Some injectors I bought new simply don't exist anymore and no trace of their existence on the net other than on this forum. There is always that risk.

Messing around with serviced injectors is a waste of time and money in my personal experience. I often go to the wreckers and get a good set of used if I am only needing replacements and be done, they usually work flawless anyway if the fuel system on the car they came off was in decent condition and not full of rust and corrosion. Just check if the spray looks good and for obvious issues, few extras at the wrecking yard is always a good idea. Some wreckers track ks and what car they came from, so that can help to pick lower k and fresher injectors. Most are help yourself deals, so pot luck there.

The thinner trick should hopefully help save good but otherwise gunked up injectors from the bin and worse the ultrasonic leak generator

[VTXU8]

Not sure why but i've seen where some workshops recommend using brake fluid in ultrasonic cleaners for cleaning injectors.

[Charlescrown]

Brake fluid OMG what next. I'd have to have a look at what I'm using ATM. I'm sure it's a caustic cleaner.

[delcowizzid]

We use proper injector cleaner ultrasonic fluid smells a lot like simple green lol.i just had to do my alloytech ones they were stucknshut from sitting and I pulsed them all on the car and got it running but we're still dirty enough to have the flow all up the shit.runs great now they are all clean and flowing the same amount lol

[Asho88]

Back to the original topic I’ve got fuel pressure! Pulled the pump back out the weird joiner thing was majorly on the piss likely my issue of not having the pump tight enough and it had a split. Replaced it with submergable hose thought my gauge shat itself was sitting on 80 psi! Turned it down and she’s holding well. I’ll test to see if it starts on its own accord tomorrow thanks for all the advice and suggestions cleaning my injectors will likely be my next job lol.