Advice on Cleaning Injectors

[Hutty 10]

As a non-mechanic I was wondering how easy it is to remove and clean the injectors on my VR6?

Are there any special tools required? Any particular products?

 

The car has been into Steve at C&R Enterprises after 12 years of very little use. He's done an amazing job on it but it's not quite running as it should yet. It takes a lot of turning over before it starts and is pretty smoky for a minute or so. It also runs rough whilst cold. It's fine once things have warmed up. Rather than constantly paying for work I wondered if there were any things I could do myself.

 

I've run some good quality injector cleaner through a tank of fuel, but I think the injectors are probably still dribbling and causing the cold start problem.

 

Thanks.

[robrado974 1]

There will be reviews on you tube for the injectors. Regarding the cold start problem have you changed the blue temp sensor in the block ?.

[Geeba 0]

Sonic cleaning, or new ones would be my thoughts

[seanl82 23]

Mrinjector has good reviews for cleaning them and you'll get a report with flow rates pre and post cleaning. Aside from standard tools to remove the fuel rail, you should be fine but just be careful not to wriggle them too much or you'll break the plastic part of the tip. Just disconnect the battery and connection to the rail, and the vapour tube to the inlet and you should be fine mate. You can do it in a normal ultrasonic cleaner for jewelery, but you obviously won't know what the pattern and flow are like before and after

[Hutty 10]

Thanks for the info gents. I haven't changed the blue temp sensor so I'll look into that. Mr Injector sounds like the way to go, had no idea that sort of service was available.

[Dox 23]

Id run it for a few 1000 miles first to soften the lacquer deposits left behind from the stale fuel, 12 years is a long time being sat around and I think you’ll find the engine will respond well to being used enthusiastically and begin to run much better for it

[fla 9]

pull the spark plugs and have a look at the deposits and colour on them. It will give a good indication of how the injectors are performing. As above you can clean them well with a good ultrasonic cleaner. You can also get one of those injector pulsers which also allow for a can of injector cleaner to be sprayed through whilst being pulsed. I just bought one recently, not got round to using it yet as I've also just cleaned both my spare sets of injectors! Change the o-rings on the injectors as well.

[Hutty 10]

The spark plugs were changed last month when Steve gave the car a good service and going over. It's running a lot better but I'm still concerned about the starting which isn't improving. Having said that, I've only done 700 miles or so in the month since I've had it back from the workshop. Before that the previous owner had kept it largely SORN. Having checked through the MOT/service history I know it's only done 1000 miles in the last 12 years.

 

Maybe the best thing to do is keep filling with V-Power for a couple of tanks and see if there's any difference.

 

Any thoughts on whether putting another dose of injector cleaner in the fuel tank will help?

[Dox 23]

When cold and the engine is slow to start, how fast does the engine crank?

 

I presume the oil has been changed for the correct type?

 

Its been known for the oil pressure relief valve to jam providing too high a pressure to the tappets preventing the valves from closing completely, losing compression. This is worse when the engine is cold because the oil is thicker and the pressure higher.

[_Matt_ 32]

Have you checked there's pressure in the fuel rail and the pump is priming on cold start? Easiest way to get an indication would be to whip a fuel line off (have a rag and something handy to catch any fuel) before starting it from cold. You should be hear the fuel pump prime when you turn the ignition on too.

 

I have what I believe is a problem with my injectors but I don't have a cold start issue. Mine starts well when cold but takes many cranks when left for 20 mins after a drive. Having changed the coil, HT leads, sparks, cam sensor (fault code), crank sensor, fuel pressure reg, thermostat, the 3 sensors in the housing and the rad fan switch I'm still left with a warm start issue and a very slight occasional vibration at idle.

 

My theory is my injectors are leaking so when I try to restart when warm there's too much fuel in the chambers and the air/fuel ratio is off. My theory also extends to the vibration at idle - too much fuel is dripping in. I've had a quote for 83 quid to have them checked and fixed via mrinjector. I have to extract them though.

[Hutty 10]

There's definitely pressure in the rail because I had to replace the supply pipe to the rail as the joint had perished.

 

Oil pressure relief valve has been replaced and the engine cranks over at normal speed during starting.

 

Lots of good suggestions coming from the forum. I think the first priority has to be the integrity of the injectors.

 

Thanks for the help.

[_Matt_ 32]

Sounds like a good place to start (and hopefully end) then. I have read somewhere but can’t find now that VW expected the injectors to need servicing at somepoint (100k?). So with that in mind it’s worth getting them looked at as part of maintenance anyway (that’s my logic anyhow!)

[steveo29 0]

send them away for cleaning

 

all inj cleaner in the tank will do is loosen any deposits then they will collect in the micro filter thats inside the injector , its not a massive amount of money to have them cleaned and checked

 

if its smoking might be a stuck piston ring