Cleaning Injectors Advice

[944_science]

I took off the fuel rail and then injectors while trying to do speed sensor, I got slightly side tracked. http://forums.pelicanparts.com/showthread.php?t=455823&highlight=cleaning+injectors

After reading through some posts, I think I will just try to clean them up myself. Thinking of sonicating them in either ethanol, benzene, or isopropanol while pulsing the injector. I was just wondering if submerging the whole injector was good idea?

[John_AZ]

I used the article written my AFJuvat from our TECH SECTION above ^^^radio button.
http://www.pelicanparts.com/techarticles/944_fuel_injector_clean/944_fuel_injector_clean.htm

Sending them to www.Witchhunter.com will give you a perfect matched flow set.

GL
John_AZ
1988 924S + 1987 924S

[944_science]

Thanks, nice write up. I guess I'll sonicate them in benzene and methanol (basically break cleaner) and then back flush with methylene chloride (carb cleaner). I can't seem to get the hats off though, and don't want to damage the injectors. They look to be in good shape as well as the o-rings. Maybe I'll just leave them? Or any tricks to getting them off?

[John_AZ]

Hats will crack-held in place with groove on injector tip. I suggest to get new gaskets as well.
Your yellow seal ring was like mine. I went to a local VW parts house to get replacements. Some of the kits sold as OEM have grey or light blue seal ring and the "hat" is taller. The injector spring on tall hats is too deep and may not give the correct spray pattern. My cost at VW shop was $4 per kit. Take along one injector for eyeball measurement.

GL
JOhn_AZ

[KitCarlsonEMS]

Here is a trick. Wiggle a 8mm ID hose fuel over the cap and use it to pull the cap off.

Actually, first use the hose to back flush the injector by filling with cleaner then use air pressure (about 5 psi) while pulsing the injectors.

The problem now is to get the cap out of the hose. It is best to replace the cap with a new one. Otherwise carefully cut the hose. Danger!!! It is easy to cut fingers.

[944_science]

Thanks for the info guys. I couldn't seem to get the caps off and didn't want to force it so I just cleaned them up by sonicating in methylene chloride. They cleaned up pretty nicely and most of the loose paint came off, the gaskets are a little swollen but i think they will return to normal. Thinking I will paint them with high temp paint before I put them back. On to cleaning the intake while decide what to do about my stuck speed sensor........

[porsche4life]

If they still dont flow right witchhunter is fairly fast. I just got a set back from them for the VW. Dont have them in yet however so I will tell you how good they did when i know.

[944_science]

Yeah, let me know. I flow tested them with pressurized air/solvent but didn't really have a reliable way to compare the flow from injector to injector. The spray pattern looked pretty good though. I guess I'm trying to save a few bucks but if I still have problems down the road it was easy enough to pull them to have witchhunter clean them up for me. Man I'm trying to finish up the this power point presentation and all I can think about is wrenching and getting her back on the road!!! Spring is near, which is good for those of us who don't have a garage to work in...

[944_science]

I put everything back together, torqued fuel rail mounting bolts, jumped fuel pump and I'm leaking from injectors 1-3 at the intake. I opted not to replace o-rings and hats because they cleaned up well and didn't have any noticeable damage. Oh, and I used a bit of motor oil on the o-rings to lubricate before putting together. Has anyone had leaking problems after removing rail? Should I use some other lube when putting injectors into intake, it's possible the oil wasn't enough and the injectors aren't sitting right. Thinking I should have just replaced hats and o-ring to begin with. Any thoughts would be great.

[porsche4life]

I havent had any leaking problems on that VW that were rail related. I have one hose that has developed a leak. The guys at witchhunter really did a good job on those injectors. They looked like new and the car pulls even harder now. Especially when you get the g-ladder wound up.

[944_science]

OK, So I used some silicon grease and reinserted the fuel rail/injectors into the intake ports. Jumped fuel pump and now only 1 and 3 are leaking. But wait, with only the pump jumped and without cranking the engine, I shouldn't see any fuel coming out of any part of the injector correct? When I was bench cleaning them I flushed them under pressure but maybe only 5-10 psi and no leaks. I guess I will pull them and pressure test at a higher psi.

[djnolan]

replacing the o-rings is not expensive and they should be available locally. they may be out of round or baked. did you also clean the port in the intake where the injectors seat with gumout or berkley 2+2? if you are going to all of this trouble replacing the hats or pintels is also recommended. they could be eroded inside and affect the spray pattern. if you did all of this could it then be the pressure regulator causing the leak?

[944_science]

Fuel pressure regulator is new, I guess I'm just concerned with the injectors leaking fuel when they're not firing. I did clean the injector ports with cotton swap and solvent, I will re-clean and replace o-rings and hats.

[944_science]

Before I buy new hats and o-rings, I was just wondering if someone could confirm that the injectors should not be delivering fuel with only the fuel pump jumped?

[porsche4life]

They shouldn't fire if the key isnot on they have their own power supply independent from the pump

[944_science]

That's what I thought, so I guess I'm dealing with leaking injectors? The car was running rich with a broken FPR, changed the FPR and still running rich. I guess this could be why, injectors leaking fuel into cylinders even when not firing. I think I might have just made them worse when I pulled the rail. This could explain some of the rough starting issue I'm having. Car runs like it's flooded for about a minute when I first start it.

[hpaulb]

I did a writeup some time ago. I take them in to a local injector pump maintenance shop. They put them on a test jig and run cleaner through. Jig also measures flow rate with simple measuring cups under each. 4 at a time. at different speeds. Total cost with new seals is 17$ for the set. Can't beet that.

[944_science]

Thanks, for the info. There are some local places here, but again the injectors are leaking fuel under pressure, which I don't think they should be. I'm not sure that new hats and o-rings are going to fix that, any thoughts?

[porsche4life]

Whitchhunter does all of what hpaulb describes for 18 and you dont have to mess with it all.
Also I would leave them alone after the cleaning. To me paintings sounds like a very bad idea.

[944_science]

Thanks guys for the info on cleaning/flow testing but no one has yet to directly answer my question about the injectors leaking. With the injector under pressure from the fuel rail and not firing, should the injector be leaking fuel? When I look at the injector, the o-ring and small spacer seem to function as a seal when the injector fires, keeping the fuel spray from exiting out of the intake port where the injector sits, is this correct? The spacer and o-ring don't function as a seal for the body of the injector, as fuel is only supposed to exit out of the small "mushroom" at the tip of the injector while firing?

My options:

1) $35 for an injector seal kit, if the injector itself is leaking this won't help.
2) Approx. $100 for whitchunter to do their thing, do they charge if injector is bad?
3) $149 shipped for a set of new Bosch 02800150159 injectors.

I guess I just don't want to throw money at the problem, and end up having to go route 3) in the end! Your wisdom is greatly appreciated!