Can anyone tell me the typical symptoms of a leaking injector?
Also, how can I test for a leaking injector?
Thanks
Typical symptoms of a leaking injector.
Moderator: martauto
-
staley_turbo
- E30 Zone Camper

- Posts: 1391
- Joined: Tue Jan 19, 2010 11:00 pm
- Location: Leicester
Poor starting or missing when cold.
Take the rail out with the injectors in, turn key so the pump primes and look for a drip.
Take the rail out with the injectors in, turn key so the pump primes and look for a drip.
-
jimbom30cab
- Tech 1 freak
- Posts: 7634
- Joined: Mon Oct 12, 2009 11:00 pm
- Location: in the garage
that's the easyest way, you could also put a pressure guage on a pressurised fuel rail and do a drop test, if there is a leak the pressure will fall off overnight, but that doesn't help ID the faulty one. I bought a new set from the USA for about £40 which was cheaper than getting them refurbished.
I have a cold running issue thats becoming much more frequent, when I start my car from cold, for the first 15 seconds it's very lumpy like is on 5 cylinders.
I can wait and it sorts itself out after around 15 secs or I can push the revs past 3k and it then blows a rich sooty plume out the arse and then idles as it should instantly.!
I'm thinking I have an injector thats dribbling overnight... and by revving it, it's purging the excess fuel from the affected cylinder. Sound plausible?
I can wait and it sorts itself out after around 15 secs or I can push the revs past 3k and it then blows a rich sooty plume out the arse and then idles as it should instantly.!
I'm thinking I have an injector thats dribbling overnight... and by revving it, it's purging the excess fuel from the affected cylinder. Sound plausible?
-
staley_turbo
- E30 Zone Camper

- Posts: 1391
- Joined: Tue Jan 19, 2010 11:00 pm
- Location: Leicester
Sounds like it could be injector. I can say (and a few others on here) that an injector recon is a good idea anyway. There 20 years or so old now.
-
jimbom30cab
- Tech 1 freak
- Posts: 7634
- Joined: Mon Oct 12, 2009 11:00 pm
- Location: in the garage
-
staley_turbo
- E30 Zone Camper

- Posts: 1391
- Joined: Tue Jan 19, 2010 11:00 pm
- Location: Leicester
£100 will see a good recondition of your original injectors.
-
jimbom30cab
- Tech 1 freak
- Posts: 7634
- Joined: Mon Oct 12, 2009 11:00 pm
- Location: in the garage
Not yet tbh
The 535i injectors (Bosch 203) are 185cc/min.
They can fuel up to 222hp at 100% duty cycle (assuming they are flowing 100%) at 85% duty cycle they can feed 189hp or so.
185cc/min = 17.6lb/hr
So am hoping they should be ok and the ecu map will be ok also
I got loads om genuine m30 ones to swap back to if needed
Ta
The 535i injectors (Bosch 203) are 185cc/min.
They can fuel up to 222hp at 100% duty cycle (assuming they are flowing 100%) at 85% duty cycle they can feed 189hp or so.
185cc/min = 17.6lb/hr
So am hoping they should be ok and the ecu map will be ok also
I got loads om genuine m30 ones to swap back to if needed
Ta
-
jimbom30cab
- Tech 1 freak
- Posts: 7634
- Joined: Mon Oct 12, 2009 11:00 pm
- Location: in the garage
Might be joining you if these refurbd ones are no good, I'll get the car on the RR and see if it leans out at high revs.
Need to get the lump back in first though, so much to do but now have everything to finish off the build apart from an m3 exhaust and Danthe fan loom. Just need a free weekend to get cracking but got the kids this weekend
Need to get the lump back in first though, so much to do but now have everything to finish off the build apart from an m3 exhaust and Danthe fan loom. Just need a free weekend to get cracking but got the kids this weekend


