Injector(s) dying? Whos got the cheapest legit 12's
- Thread starter colo_evo
- Start date
Pretty sure it's machined off. It's to perfect to be hand ground.
I don't even know if I'll put them in. Most the big retailers sell the vdo injector, so they can't be total junk.
I still don't know if my injectors are bad. I was really hoping the car would throw a misfire code for a cylinder but that hasn't happened yet. I wish some people with experience in the starting issue I'm having would confirm that an injector swap cured their problems.
Here's a test you can do. Let the car get up to temperature (oil > 160*) and park it. Wait 30-45 minutes and go restart the car. Does it long crank, or stumble / sound really weak on startup?
If it does either of those, there's a good chance its the injector - it leaks fuel into the cylinder and given a short time to accumulate it becomes way too rich to ignite until you turn it over a few times and and purge that cylinder so you either get a long crank or a really weak-sounding startup.
Cold starts and immediate warm restarts don't have that issue as fuel either didn't have time to accumulate in the cylinder, or has totally evaporated.
If it does either of those, there's a good chance its the injector - it leaks fuel into the cylinder and given a short time to accumulate it becomes way too rich to ignite until you turn it over a few times and and purge that cylinder so you either get a long crank or a really weak-sounding startup.
Cold starts and immediate warm restarts don't have that issue as fuel either didn't have time to accumulate in the cylinder, or has totally evaporated.
Thanks for the input. Hot starts it's intermittent whether or not it has issues. I would guess 90% of the time it starts great when soaking for less than 8 hrs. Cold starts it immediately fires and hesitates for a few seconds after crank.
The funny thing is the initial crank and run-up is awesome, no labored or weak cranks ever. It hits 1200rpm a split second after the starter hits. It's only after the initial rpm spike it has trouble idling.
The vdo are the same Siemens blah blah blah it like control arms with logo ground off I pretty sure they are oem injectors I don't think they a remanufactured either but could be wrong
Mine is the same way. It never has trouble starting from dead cold but stumbles for a bit because I run full e85. Are you running any ethanol at all or straight pump gas?
Alternatively if you have a borescope you could start the car from dead cold, shut off after ~5 seconds, and immediately pull all plugs and borescope cylinders looking for fuel. The high pressure fuel system runs at 2,000+ psi even at idle on a cold start until coolant exceeds 104*F, as opposed to ~7-800 psi at idle normally.
They smell like machining oil, solvent or a mix of the two. They just don't look new to me, so that's why I assume they're remanufactured. I'm far from an expert in this arena.
I'm running straight e10 pump gas.
My next plan was to cold start it and let it run for 1 or 2 seconds while it's still stumbling then turn it off and have a look at the plugs to see if there's a smoking gun.
Another thought I had was flash to a high boost map and see if I could get a misfire code. Running higher boost exposed a weak coil a few months back. Maybe it'll do the same thing for a faulty injector.
Good luck with that... I made 692whp on 30 psi with a bad injector LOL
I would hope vdo would not pull shady tactics like that if you check the serials online shows as genuine and new
For me i feel like new injectors helped part throttle most half throttle feels almost like wot now and smoother but only difference that not subjective is at idle i no longer get random hiccup don't know if that helps
