Testing injectors, ? Options

[Hammy]

How do I do a visual test/check on fuel injectors outside the car on the bench? Any way to tell they're spraying right? I don't want to install this engine and find the injectors are crap.

[Twystd1]

Zack,

I would send em out for testing if you REALLY want to be clear if they are in good shape.

I think you will probably find out you will need to send in 6-8 injectors to get a matching set of 4 good ones. This assumes you are using original injectors from 1976 or earlier.

I won't use RC injectors anymore. Too may complaints from the ricers.

You may want to change your post to read....
Who knows of an INJECTOR TESTER IN THE MODESTO AREA.

Cause you probably don't have the facility's to REALLY test them at home.

YOU COULD hook em up to your engine's fuel system. Ground the coil wire. (KEEP SPARK AWAY FROM FUEL)

Get yourself a glass jar and watch the spray. At least that will tell you if it has a pattern or is just puking fuel.

The best approach is to send em out to a pro. IMnonHO.

Cheers,
Clayton

[Hammy]

Zack,

I would send em out for testing if you REALLY want to be clear if they are in good shape.

I think you will probably find out you will need to send in 6-8 injectors to get a matching set of 4 good ones. This assumes you are using original injectors from 1976 or earlier.

I won't use RC injectors anymore. Too may complaints from the ricers.

You may want to change your post to read....
Who knows of an INJECTOR TESTER IN THE MODESTO AREA.

Cause you probably don't have the facility's to REALLY test them at home.

YOU COULD hook em up to your engine's fuel system. Ground the coil wire. (KEEP SPARK AWAY FROM FUEL)

Get yourself a glass jar and watch the spray. At least that will tell you if it has a pattern or is just puking fuel.

The best approach is to send em out to a pro. IMnonHO.

Cheers,
Clayton

Thanks Clayton.... any idea how much that'll run me ? I'm runnin' low on the 914 funds (IMG:style_emoticons/default/wink.gif)
I was hopin' to install this weekend but maybe it'll have to wait... The guy SAID the FI system was working perfect, but the injectors look perty rough as is. And I only got 4. How do I source good used ones for a reasonable price if need be?

[Twystd1]

Theres a place in San Diego that does it cheap AND does good work. Shoot over to the club board and do a search. There are a couple of threads over there that discuss that particular injector rebuilder. I forget the name dammit. Or ask Bradholio. He is on the club board this week. He knows off the top of his head.

The guy I use is kinda expensive. And you probably don't need that kind of nats ass perfection. (Joe Jill at Superior Automotive)

You will probably spend about 35 - 50 bucks per injector plus shipping.
Thats to clean and flow em. If ya get stuck. PM Slits, Joe Sharp, Leamon, post here for injectors or me... And we can see what we have in our stash.

Whatch U got.??? 1.8, 1.7, or 2.0?


OOOPs. I just remembered that Slits knows the place in San Diego as well as a couple of others injector cleaner shops.. PM him here AND at ClubNarp. And ask him.

Clayton

[Hammy]

Theres a place in San Diego that does it cheap AND does good work. Shoot over to the club board and do a search. There are a couple of threads over there that discuss that particular injector rebuilder. I forget the name dammit. Or ask Bradholio. He is on the club board this week. He knows off the top of his head.

The guy I use is kinda expensive. And you probably don't need that kind of nats ass perfection. (Joe Jill at Superior Automotive)

You will probably spend about 35 - 50 bucks per injector plus shipping.
Thats to clean and flow em. If ya get stuck. PM Slits, Joe Sharp, Leamon, post here for injectors or me... And we can see what we have in our stash.

Whatch U got.??? 1.8, 1.7, or 2.0?


OOOPs. I just remembered that Slits knows the place in San Diego as well as a couple of others injector cleaner shops.. PM him here AND at ClubNarp. And ask him.

Clayton

Eez a 1.7...... At 35+ I don't think I can afford it..... sheeeeit. I still gotta buy all the vacuum lines and other misc. stuff. Should I chance it and clean them in something at home and hope they're working fine?

[Spoke]

I'm in the same boat trying to get a FI system working again after years of sitting in a box. I have dual Weber carbs as a back-up but really would like to get the FI working.

I was thinking to test the injectors (I have 8), I would connect them to a length of hose, fill the hose with Kerosene, and connect the other end to my compressor.

Pump up to 30-40 psi, and connect the injector to a battery through a push button switch.

My goal is to see if the injectors work and if the spray pattern is ok by spraying into a jar.

Will this work? Will the kero damage the injectors?

Spoke

[blitZ]

I had this place refurbish my injectors. They will send you a before and after test and replace the seals and pintles (sp?) for the price stated. I thought they did a good job at a good price.

Cruizin Performance

[type11969]

Has anyone ever had any luck using a modern injector as a replacement?

Sorry for the slight hijack!


-Chris

[BMartin914]

You can buy an injector testing unit which will fire the injectors a set # of times (the one I use will pulse 10, 50 and 100 times.

Connect to a 12V battery, and with a can of carb cleaner, fill the injector, pulse it, and blow the cleaner thru with shop air.

Do it as many times as necessary until you're pattern is good. The tester has got to be under $40 but I did not buy the one I use.

As far as matching and flow-testing are concerned, witchhunter in Seattle charges $17/injector. But you're at almost $100 after shipping both ways for a set.

------------------------------------

You could also pull the injectors out of the runners, put them in small jars, pull the dizzy, turn the key on and spin the rotor. You can at least tell if/how they are spraying using this method.

[slim72914]

Actron makes an injector pulser so you can simulate the pulse the injector actually sees. Not an exact science but if you do the jar test you will be able to see if they are atleast all making the same spray pettern. Actron part #cp7819
I found mine on Ebay local stores dont carry em.

[BMartin914]

Actron makes an injector pulser so you can simulate the pulse the injector actually sees. Not an exact science but if you do the jar test you will be able to see if they are atleast all making the same spray pettern. Actron part #cp7819
I found mine on Ebay local stores dont carry em.

spot on. exactly what I was talking about.

[jk76.914]

I've tested mine a couple of times. Generally, when I had the time to work on it, I didn't have the bucks, so I had to figure a lot of things out. No 914world.com back in the 80's when I got started.

I use a long length of hose- maybe 6 feet. You don't need the spensive fuel injector hose, as you're using it for such a short time and outside the engine compartment. Regular American fuel hose works OK. Maybe $4 for 6 feet at NAPA.

Also, I made an extension cord from an old leaking injector- broke it apart and used the electrical socket, soldered to the end of a 6 foot piece of wire. The other end is a fuel injector pigtail that I cut off a VW bus in a junk yard. Cost me 50 cents plus a round trip to the junk yard on a Saturday morning.

Disable the coil, and ground the center wire. Hook up the injector using the long hose, with hose clamps on each end (don't have to be expensive FI clamps for this), and the extension cord you built. Stand as far away from the car as you can, point it at a piece of brown paper, and have someone else crank the engine. When you've had enough- probably 3 or 4 cranks, tell them to stop cranking. The thing you'll notice right away is how loud it is. Don't let it startle you into dropping the injector into the dirt.

There are four tests you can do yourself-
1. pattern. Check it out as it squirts, plus the pattern it leaves on the brown paper. You want to see small small droplets, coming out in a cone shape. Do all 4 and you'll see right vs. wrong. It's highly unlikely that all 4 will be bad, so you can learn what's OK by experience. It's pretty likely that all 4 will be OK. (reference- Bosch Fuel Injection and Engine Management Manual)

2. leakage. Unplug your extension cord to the injector you're testing, but keep the hose attached at both ends. Crank the engine. This will build up fuel pressure. With the injector pressurized, but not opening, you may see a drop of fuel form on the tip. Two drops every minute is a max acceptable. (reference- Clymer 914 manual) Use a watch to time it. Ideally it doesn't drip at all. Don't crank the engine for the whole minute though!!! You'll burn something out, like your starter. Several turns will pressurize it and the check valve in the fuel pump will hold it long enough for the test. If you're getting into EFI tuning, you really should own a fuel pressure gauge, and it should be hooked up for this, because it's possible your check valve isn't checking.

3. While you're waiting for drops to form at the tip, carefully check around the body of the injector for seepage. The body is formed from a few tubular pieces, stacked on top of each other and sealed with o-rings. They can leak, which is dangerous, in addition to causing hot start problems by bleeding off the residual pressure in the system. (reference- Bosch Fuel Injection and Engine Management Manual)

4. resistance. This is the easiest and safest test. Just measure the resistance across the two pins on the injector. The spec is 2.4 ohm, but anywhere between 2 ohm and 3 ohm is OK. (reference- Porsche factory shop manual.)


Things you can do- for #1 and #2- put it all back together, and then run a can of Chevron Techron Fuel Injector Cleaner through with about 8 gallons of gas. It's amazing stuff! There's a good chance that's all it needs and you're done. If you still have the problem, you can try sending it off to a fuel injector cleaning service, or you can put that money towards new injectors.

For #3 and #4- replace the injectors. I'm currently having no problem with my Niehoff injectors for 1974 Mercedes 450 SEL. They were only $49.99 at PartsAmerica.com brand new- not refurbished. I only have 2000 miles and 2 years on them though, so it's early to tell how the reliability stacks up.

There's no such thing as a "rebuilt injector", though some advertise them as such. The cleaning services clean them in solvent, back flush them, and replace the inlet screen, but they don't "rebuild them", which implies replacing worn parts. Important to note though- they also measure fuel volume and assess spray pattern. Fuel volume you can't easily or safely do at home, in my opinion.

That's what I've learned after 24 years with my '76 2.0.

[jimkelly]

www.witchhunter.com cleans the worst looking injectors to look pretty amazing compared to what I sent them - they test before and after several things - they engrave each injector to match the number on their report too.

--

450sel pn seems to be 57512

at www.partsamerica.com

http://www.partsamerica.com/ProductDetail....677&PTSet=A

the other jim kelly in DE

[p914]

In Portland there's a place Automotive Products.
They check em for $10 each.
Clean and repair for $22 + parts each.
Just had all 4 of mine done and it ran $135 all together.
They are all matched up now and the flow is better than original at around 362cc compared to stock at 317cc.

Also I've included a chart I found with injector part #s and details
 fuel_injector_part_numbers.xls ( 172.5k ) Number of downloads: 1961

[orange914]

have you checked the fuel injection shop on 9th st, i think its called api

mike

[toon1]

Has anyone ever had any luck using a modern injector as a replacement?

Sorry for the slight hijack!


-Chris

Yes, it can be done, it takes a little work.

[euro911]

Have any of you cleaned your injectors by dunking them in an ultrasonic tank (the hot water type) for a specified period of time?

[toon1]

That may work, what happens to the inj's is the tip of the pintle(plunger) gets worn and then the tip leaks.

Also the body starts to leak.

Neither one of them can be fixed

[type11969]

What injectors work and what are the modifications that are necessary?

Has anyone ever had any luck using a modern injector as a replacement?

Sorry for the slight hijack!


-Chris

Yes, it can be done, it takes a little work.

[toon1]

What injectors work and what are the modifications that are necessary?

Has anyone ever had any luck using a modern injector as a replacement?

Sorry for the slight hijack!


-Chris

Yes, it can be done, it takes a little work.

to use different inj's with the current fuel system, you will need to find an inj', that is,

Low imp.
21lbs/hr@ around 29psi of fuel pressure. with A new fuel pump and reg. you can run higher pressures and still get the same inj. fuel flow

A fuel rail will need to be fabbed because the newer inj's have an Oring ontop not a hose barb,no big deal.

The pulse width on the stock system cannot be changed so the flow rate of the inj's have to be close to the same as stock.

I am going to be running ford prob inj's that flow 21lbs/ hr @ 43psi HIgh imp. BUT I am using megasquirt so I can adjust things

There are plenty of options, avail for the stock system.