engine stethoscope (what should my injectors sound like?)
Discussion
Your stethoscope is designed for exactly that, you are listing for something different to other components, so it looks like you have found your problem. As for what the problem is, I think you need to start stripping it down if thats possible and take it from there.
What are the symptoms of what caused you to start listening to them in the first place?
What are the symptoms of what caused you to start listening to them in the first place?
thanks for reply
car start runs, idles and drives fine......except for one minor issue.
if left overnight/longer for the first 30-60 seconds of warm up. the car will have a terrible bog/hesitation between 1800-2000rpm.
it runs fine either side of this rev range during warm up too.
over this brief warm up period the problem reduces gradualy (less severe bogging) until it disappears
i can turn the car off an leave it for a fair few hours (9hr work shift) and the problem doesn't return.
ive replaced almost every engine sensor at this point. no phantom inlet vac leaks or exhaust leaks. new coil packs, spark plugs all look good/even colour. well maintained otherwise.
only got the stethoscope out for a "joke" was a cheapy amazon thing i got a year ago....might of done its job
my thinking is, hot engines mask poor spray patterns.
this one injector sounds muted and like its flowing a lot.
like the pin seat is gummed up resulting in a muted clunk and maybe its bypassing/leaking more fuel than normal, hence the wooshing.
if it is bypassing/leaking more fuel it could mean my other injectors arnt seeing as high a pressue reducing their spray pattern.
if its leaking overnight, it might pool fuel in my inlet....causing other issues.
it could just not be opening enough aswell making that one cylinder lean.
its a weird problem...the boggy 200rpm band between 1800 and 2000rpm make me think ecu/electrical i.e. a sensor fart
but as its only a cold start problem....it feels like it should be more of a mechanical/physical problem.
thanks again for the input
car start runs, idles and drives fine......except for one minor issue.
if left overnight/longer for the first 30-60 seconds of warm up. the car will have a terrible bog/hesitation between 1800-2000rpm.
it runs fine either side of this rev range during warm up too.
over this brief warm up period the problem reduces gradualy (less severe bogging) until it disappears
i can turn the car off an leave it for a fair few hours (9hr work shift) and the problem doesn't return.
ive replaced almost every engine sensor at this point. no phantom inlet vac leaks or exhaust leaks. new coil packs, spark plugs all look good/even colour. well maintained otherwise.
only got the stethoscope out for a "joke" was a cheapy amazon thing i got a year ago....might of done its job
my thinking is, hot engines mask poor spray patterns.
this one injector sounds muted and like its flowing a lot.
like the pin seat is gummed up resulting in a muted clunk and maybe its bypassing/leaking more fuel than normal, hence the wooshing.
if it is bypassing/leaking more fuel it could mean my other injectors arnt seeing as high a pressue reducing their spray pattern.
if its leaking overnight, it might pool fuel in my inlet....causing other issues.
it could just not be opening enough aswell making that one cylinder lean.
its a weird problem...the boggy 200rpm band between 1800 and 2000rpm make me think ecu/electrical i.e. a sensor fart
but as its only a cold start problem....it feels like it should be more of a mechanical/physical problem.
thanks again for the input
Years ago a good article said for running problems, start with the injectors and work out. Which can make a lot of sense....apart from injectors usually being very very reliable.
You could pull them out and send them to ASNU for a test/clean etc. At least that would rule them in or out.
You could pull them out and send them to ASNU for a test/clean etc. At least that would rule them in or out.
stevieturbo said:
Years ago a good article said for running problems, start with the injectors and work out. Which can make a lot of sense....apart from injectors usually being very very reliable.
You could pull them out and send them to ASNU for a test/clean etc. At least that would rule them in or out.
^^^^Wot 'e said.You could pull them out and send them to ASNU for a test/clean etc. At least that would rule them in or out.
That would also be my first step.
A while ago I have a Volvo v40 which would "missfire" slightly at lower revs in higher gears, actually it obviously did it all of the time but was more noticeable then.
Sent the injectors off, 1 was sub-standard. Got another.... Sorted.
stevieturbo said:
ASNU
That's the phrase I was trying to remember. Yes, a flow and leak test would probably be worth it on such old injectors, but be ready to be told they're all scrap. 
In the meantime, leave it over night, take the sparkplug out and stick an endoscope in? You'll soon see if there's a puddle of fuel in there.
Depending how convenient it is for you to take the injectors out, I'd be tempted to give it a dose of PEA based injector cleaner first and see if that helped. Also check the exhaust header temperatures when you get the stumble and see if the cylinder with the dodgy sounding injector is running cold, supporting the theory it's got a misfire. Then take that plug out and see whether it's wet or dry. (Wet just confirms that it's got a misfire, but dry might indicate it's misfiring due to insufficient fuel, which further supports your diagnosis.)
fuel pressure tester came today....my fuel pressure seems within spec despite age. please confirm
pump on, engine off, 3.2bar
pump off, engine off, sits at 2.6bar (no leak down in 10 minutes)
pump on, engine on (idle) 2.6bar
pump on engine on (reving up) shoots straight to 3bar and slowy drops down to 2.6bar as engine revs increase (is this bit normal?)
multimetered the injectors pins and all have an even resistance.
ive fished 4 old injectors i have in my parts bin from a previous gti6, i think ill take them along with the car to an injector specialist.
new and used injectors for this aint cheap
pump on, engine off, 3.2bar
pump off, engine off, sits at 2.6bar (no leak down in 10 minutes)
pump on, engine on (idle) 2.6bar
pump on engine on (reving up) shoots straight to 3bar and slowy drops down to 2.6bar as engine revs increase (is this bit normal?)
multimetered the injectors pins and all have an even resistance.
ive fished 4 old injectors i have in my parts bin from a previous gti6, i think ill take them along with the car to an injector specialist.
new and used injectors for this aint cheap
jimmyhackers said:
fuel pressure tester came today....my fuel pressure seems within spec despite age. please confirm
pump on, engine off, 3.2bar
pump off, engine off, sits at 2.6bar (no leak down in 10 minutes)
pump on, engine on (idle) 2.6bar
pump on engine on (reving up) shoots straight to 3bar and slowy drops down to 2.6bar as engine revs increase (is this bit normal?)
multimetered the injectors pins and all have an even resistance.
ive fished 4 old injectors i have in my parts bin from a previous gti6, i think ill take them along with the car to an injector specialist.
new and used injectors for this aint cheap
Surely they're a fairly typical Bosch style injector ?pump on, engine off, 3.2bar
pump off, engine off, sits at 2.6bar (no leak down in 10 minutes)
pump on, engine on (idle) 2.6bar
pump on engine on (reving up) shoots straight to 3bar and slowy drops down to 2.6bar as engine revs increase (is this bit normal?)
multimetered the injectors pins and all have an even resistance.
ive fished 4 old injectors i have in my parts bin from a previous gti6, i think ill take them along with the car to an injector specialist.
new and used injectors for this aint cheap
their code is IW204
i cant find new ones tbh. in think they are out of production
used set of 4 is 100 quid on ebay.
ive looked into "newer style 4 hole replacements" google AI found me a forum thread where someone used 206RC injectors, OP said they worked fine, but others said dont use.
im going to a localish injector specialist with an ansu machine 2morrow.
maybe they can recommend me a more upto date replacement.
i cant find new ones tbh. in think they are out of production
used set of 4 is 100 quid on ebay.
ive looked into "newer style 4 hole replacements" google AI found me a forum thread where someone used 206RC injectors, OP said they worked fine, but others said dont use.
im going to a localish injector specialist with an ansu machine 2morrow.
maybe they can recommend me a more upto date replacement.
jimmyhackers said:
their code is IW204
i cant find new ones tbh. in think they are out of production
used set of 4 is 100 quid on ebay.
ive looked into "newer style 4 hole replacements" google AI found me a forum thread where someone used 206RC injectors, OP said they worked fine, but others said dont use.
im going to a localish injector specialist with an ansu machine 2morrow.
maybe they can recommend me a more upto date replacement.
Looks like a bog standard very common Bosch style. Google suggests 265cci cant find new ones tbh. in think they are out of production
used set of 4 is 100 quid on ebay.
ive looked into "newer style 4 hole replacements" google AI found me a forum thread where someone used 206RC injectors, OP said they worked fine, but others said dont use.
im going to a localish injector specialist with an ansu machine 2morrow.
maybe they can recommend me a more upto date replacement.
This would be very close, just get a wiring plug adapter or make up new connectors.
https://finjector.com/eng/ev14_12_ohm_273cc_e_30_u...
Although I'm sure your ASNU guy will also be able to either clean/check yours and get them working well again or supply something that will do.
There are quite a few of the actual ones on ebay, but obviously they're all very old now and you'd never know their history either.
jimmyhackers said:
fuel pressure tester came today....my fuel pressure seems within spec despite age. please confirm
pump on, engine off, 3.2bar
pump off, engine off, sits at 2.6bar (no leak down in 10 minutes)
pump on, engine on (idle) 2.6bar
pump on engine on (reving up) shoots straight to 3bar and slowy drops down to 2.6bar as engine revs increase (is this bit normal?)
Pressures are fine.pump on, engine off, 3.2bar
pump off, engine off, sits at 2.6bar (no leak down in 10 minutes)
pump on, engine on (idle) 2.6bar
pump on engine on (reving up) shoots straight to 3bar and slowy drops down to 2.6bar as engine revs increase (is this bit normal?)
jimmyhackers said:
are you sure about the last one?
google says it should rise to 3 bar under wot and stay there.....
My mistake, sorry, I missed the second part of the last line, yes it should stay up at WOT pressures.google says it should rise to 3 bar under wot and stay there.....
Only caveat would be I assume you are looking at these off load?
Can you monitor when on-load?
off load testing yes,
i dont really fancy/trust having the meter hooked up while im driving about.
thats another point i will need to investigate :S
in other progress..... collected my injectors today.... report is somewhat telling (of my messings in the past).
one injector started good and ended up good
the other three started off bad and ended up good
in the past when i did my inlet manifold i swapped in spare injectors i had from another gti6 (these had been serviced in past) but didnt fit one as it had a damaged o-ring.
annoyingly....MR ASNU pointed out despite them all flowing the same flow rate after servicing the one different one had a vaguely different spray pattern to the other three.
i.e. instead of two even fan shaped jetting patterns.....the odd one had the same two fan shaped jetting patterns, except each fan had three more pronounced lines/zones in it.
luckily they are set/date stamped from factory.....so i can easily tell which is from which set.
leaves me with the predicament of.....
what exactly do i refit. one injector, three injectors, all four.
im leaning to re-matching all four.....so only replacing the duffer, meaning maybe in the future ill need to get 3 more injectors serviced.
live n learn
i dont really fancy/trust having the meter hooked up while im driving about.
thats another point i will need to investigate :S
in other progress..... collected my injectors today.... report is somewhat telling (of my messings in the past).
one injector started good and ended up good
the other three started off bad and ended up good
in the past when i did my inlet manifold i swapped in spare injectors i had from another gti6 (these had been serviced in past) but didnt fit one as it had a damaged o-ring.
annoyingly....MR ASNU pointed out despite them all flowing the same flow rate after servicing the one different one had a vaguely different spray pattern to the other three.
i.e. instead of two even fan shaped jetting patterns.....the odd one had the same two fan shaped jetting patterns, except each fan had three more pronounced lines/zones in it.
luckily they are set/date stamped from factory.....so i can easily tell which is from which set.
leaves me with the predicament of.....
what exactly do i refit. one injector, three injectors, all four.
im leaning to re-matching all four.....so only replacing the duffer, meaning maybe in the future ill need to get 3 more injectors serviced.
live n learn
not sure how well the reports been filled out tbh, only has static flow numbers, dynamic flow and flow rate in cc/min has not been calculated...
they initially flowed 60, 55, 59, 61 with a fair, bad, bad, bad, spray pattern.
after servicing they went to 62,61,60,61 with good, good/fair good/fair good/fair spray pattern.
the first of each set of 4 being the odd one out
its weird as the "newer/better" injector is the one i didnt swap in from my much older phase1 gti6 (scrapped now
)
it was one of the learner cars silverstone track owned/used for event days.
maybe they put new injectors in it over its lifetime.....
the ones that came with my current car are/were nasty. flakey chrome on outside.
my gamble is are the 3 good injectors in the car as decent as the one i had serviced.
or do i swap in all four i had serviced as a mismatched set and send the four that come out for servicing (another 80 quid ), then rematching and refitting a set of 4 when they come back.....
wallet vs car ocd :s
they initially flowed 60, 55, 59, 61 with a fair, bad, bad, bad, spray pattern.
after servicing they went to 62,61,60,61 with good, good/fair good/fair good/fair spray pattern.
the first of each set of 4 being the odd one out
its weird as the "newer/better" injector is the one i didnt swap in from my much older phase1 gti6 (scrapped now
)it was one of the learner cars silverstone track owned/used for event days.
maybe they put new injectors in it over its lifetime.....
the ones that came with my current car are/were nasty. flakey chrome on outside.
my gamble is are the 3 good injectors in the car as decent as the one i had serviced.
or do i swap in all four i had serviced as a mismatched set and send the four that come out for servicing (another 80 quid
), then rematching and refitting a set of 4 when they come back.....wallet vs car ocd :s
well....i fitted all 4 injectors i had serviced.....i wont know until tomorrow when the cars cold to see if its helped my "from cold hesitation".
the 4 that came off the car....annoyingly had 3 different date/manufacturer codes...
one to complete my set of 3 in the car, one that matches the odd one in my car and two of another code.
im going to send the one off to get serviced (only 20 quid) so i have a matched set.
and i think my fuel pressure at WOT problem was me being a fanny....i didnt open the throttle enough. its sit at a bouncy 2.8 to 2.9 bar
if i disconnect the vac line while running/wot it sits at a constant 3 bar...
im thinking i probably will have to test it under load.
the 4 that came off the car....annoyingly had 3 different date/manufacturer codes...
one to complete my set of 3 in the car, one that matches the odd one in my car and two of another code.
im going to send the one off to get serviced (only 20 quid) so i have a matched set.
and i think my fuel pressure at WOT problem was me being a fanny....i didnt open the throttle enough. its sit at a bouncy 2.8 to 2.9 bar
if i disconnect the vac line while running/wot it sits at a constant 3 bar...
im thinking i probably will have to test it under load.
Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff