Petrol injectors. A Godsend or a nightmare!

[saturnuranus]

Wotcha folks! For the benefit of anyone considering cleaning their injectors, I would like to add my experience of Jims cleaning service to this thread.

For starters, delivery time. As Jim has already stated, he cleans them on the same day he receives. I sent mine on a Tuesday afternoon, and they arrived back with me on Thursday morning via Royal Mail Recorded 1st. Make sure you send them in a heavily padded jiffy bag or preferably a box, as mine arrived at Jims slightly damaged. Lessons to be learnt!

Jim kept in touch throughout the cleaning process, and I have a picture of the flow-rate test before cleaning demonstrating that one of my injectors was duff, so had to be replaced. Fortunately Jim had a spare, but I now owe him for that one!

Once I received them back, I spent the rest of the evening re-assembling my renewed PCV system and fitting my cleaned injectors. I decided to replace the O-rings at the top and bottom of each injector and the small rubber washer that fits between the injector and the rail. I got all these for £10 from my local stealer, which Jim said is a bit pricey. I'll go elsewhere next time!

Jim was eager for some feedback regarding improvements in stability and performance of my engine, so I took it out for a blast that evening, only for a boost hose to pop off and the top hose to be leaking, which needed replacing. More lessons learnt!

After finally getting her roadworthy again, I was able to fully appreciate the magic of the work Jim had done. Straight away I noticed the car idling perfectly. For 150,000 miles I expect the odd stutter or lump when idling, but nothing, nada! Taking it on the motorway and a couple of dual carriageways I was able to relish the absence of an occasional misfire I used to get when accelerating from about 3/3.5k, not to mention vastly, and I mean vastly, improved power delivery. It's hard to describe, but immediately I found myself thinking this thing drives like new, it's great! She accelerates hard and smooth right round to the redline, as she should. Jims flow test showed one of my injectors delivering around 60% more fuel than the other 4, which as he described, will cause the system to compensate for the incorrect mixture by leaning it, meaning 4 cylinders are running lean and one is ok.

Lastly, fuel economy. I've been running round now for about a week with the computer reset, and doing my usual work run each day. My average pre-cleaning was about 23mpg. The meter is currently telling me my average is 25.8mpg, and improvement of 2.8mpg. I know these computers aren't perfect, but the journey I do is a pretty consistent sitting-in-a-jam affair, so the increase is quite believable to me. I'll report back in a few weeks time once I've got a few more journeys under my belt.

Overall? Im impressed. Jim's service is quick, easy, cheap and personal. He called to confirm I had received the injectors back and then gave me a full report on what he had found, and the work carried out. This all goes without saying that he's a jolly nice chap to deal with!

For the sake of the £40 or so it's going to cost and the couple of hours work removing and refitting, it's well worth it. My dad was also suitably impressed and will be sending his injectors to Jim within the next couple of weeks.

Bravo!

[jimathan]

Very pleased for you. Nice to know its running so well. Sound s like its made a hell of a difference, considering you didn’t realise you had a problem in the first place! Nice one
Jim

[pjay]

Originally Posted by jimathan

Hi peewee, im just outside Blackburn lancs. Time scale is in and out in one day. PM me for more info.
Regards jim

hi again jimathan- i live fairly close by, is it possible that i could bring mine to you and then collect same day, i have my sons car for the moment which by the way is a volvo 940s which if possible i would like done after i have my car back on the road, i will be more than happy if it gives that little bit of extra power and helps with the mpg, if you wish i have a mobile number you can ring and we can exchange addressesm so i can also arrange a mutual time for us to meet at yours, i am on -
07731361843. cheers - pete.

[jimathan]

PM sent
jim

[CTCNetwork]

Hi,

My 940 injectors will be coming off this weekend so hopefully I can sort out the details for this at the weekend or early next week...

Des. . .

[jimathan]

No problems Des, when your ready
Jim

[jimathan]

Many thanks to ctcnetwork. We now have a spare set of injectors for a 940.
Anyone wishing to do their 940 can now have these sent to them, to keep them on the road while theirs are being serviced.
Jim

[bb54]

hi Jim,does the regular use of fuel system/injector cleaners not sort out the varnish buildups leading to the problems you have mentioned ?

wayne

[jimathan]

Hi Wayne. Im sure it helps to some extent. What it won’t do however is remove the particulates that build up in the filter within the injector. They can only be removed by back flushing. Trust me on this, there is always loads of muck comes out. The fuel filters fitted to modern cars are very good but they don’t stop everything. In addition to the varnish type deposits, the moving parts of the injector become sluggish. This can make them slow to respond, making them stay open longer, or stay closed for longer. One thing I have noticed is that when they have been through the ultrasonic cleaner, they sound sharper or crisper. They also become more uniform when pattern testing at minimum demand at high revs. Say for instance when you just put your foot gently on the gas pedal at high speed. This makes the pick up smoother.
Think of it like flushing out a radiator. You can put all the correct chemicals in and drive around for a day or two, then flush it through with clean water. Then, when you decide its still not write, you take it off, shake it, and back flush it. You always get some more crud out of it.
Jim

[jimathan]

One other thing to consider, fuel filters are usually 4 micron. Injector filters are much smaller, when you use additives to clean out the fuel system, where does it all end up? Anything smaller than 4um will go strait past the fuel filter and get trapped by the filter in the injector. If it’s smaller than the filter in the injector, think of the damage it does to the needle and pintle on its way through.