How can you tell if the injectors are bad.

Are there any major signs.

Thanks.

 

Well mine wasn't bad, it was clogged, my 5.7L had a real bad miss, like a cylender was not firing.I checked all electrical parts...cap, rotor,plugs wires,plugs. finally took it to the shop after several tests,they flushed the system. runs better now and $500 poorer.

 

The first sign of an injector that is clogging or has a poor spray pattern is a loss of fuel economy. After that would be a slight but detectable miss, especially under 2,000 RPM. A completely clogged injector will finally create a completely dead cylinder detectable at all speeds.

Instead of $500.00 to repair, you can send your injectors to Cruzin' Performance and get them cleaned and flow-matched for about ten bucks apiece ($80.00). If you have a cold-start injector, you can usually get that one cleaned as well (I got mine done for free when I sent it with the rest of the set).

I've had a couple of very good experiences with their service.

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Later,
Vader
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"Get UP - Drop the bombshell!"
Adobe Acrobat Reader

 

Pull the wires off the injectors and test each injector with a digial meter, That will tell you which one is bad. Just did mine last week.

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Vader... you also have to mention the fact that there are technically 2 things that can cause a 'broken' injector...

1 is easy to take care of... an injector simply being clogged. The STP black bottle is the stuff to use, or if you wanna go hardcore and do it right, you send them to Cruisin' Performance...

2 is the fact that the injectors internal electrics break down... they can no longer function at par, not because they are glogged, but their internal break down prevents them... The test for this is as Suaveat69 says... If one tests bad, instead of paying out the a$$ for 1 from GM and to avoid mixmatched injectors (not the performance road) it'd be better to replace them all...

Also note that injector cleaner in a bottle wreaks havok on your O2 sensor... If you start going lean, replace the O2 before you start blaming injectors...

Hope that helps you guys out.

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1985 Camaro SC - 2.8L, auto.

http://www.xenodrgn.f2s.com/Frontright.jpg

 

I just failed emmisions with 3 times the normal rating. I paid a shop 112 to diagnose the injectors bad. There are several ways an injector can fail, and if you learn what I did, dont listen to this Listen to this
I talked to Rich at cruzin performance, and he said the exact same thing. I would have sent them to him to fix, but

A. he generally only unclogs and flow tests them.
b. I assume he does not redo windings on the little guys, because that would be a tremendous waste of time. (yeah how many other people have built a dc motor, you know what Im talking about)

and since my injectors were failing electrically, they are best replaced, and all 8 of them at that. Rich or Summit charge the same price for Accel injectors which I just replaced last friday (Fun fun!).

You can check for the injectors being bad by taking an Ohm-meter ($10-$30 at your local walmart, often part of a voltage meter) and checking the resitance between the two contacts on each injector. Mine ran about 15.9-16.2 which is good. Anything outside of 2% of them is failing. The lower, the more it hangs open etc.

Keep in mind however that testing the injector and it meeting the specs does not mean that it is not bad electronically later on, or plugged, or gummed. Nor does it mean that the injector is still working at 200 degrees.

Your best bet is to buy a kit of injectors from rich @ www.cruzinpeformance.com or go to www.summit.com for $250 and 10 dollars for 2nd day shipping, you cannot go wrong.

Look at it this way, and you cannot go wrong:

If you do it, do it right the first time.

 

My car was running bad most of the summer, after warm up it would cycle and stumble. Several mechanics thought it was the EGR valve, I replaced it and the problem persisted. I finally left the car with a local mechanic for 2 days. After a battery of tests he concluded the injectors were dead. Another problem I was having due to the bad injectors was a strong fuel smell commimng from the vapour cannister, it was filling up with gas because of the bad injectors. Well I bought a set of Acells from Cruzin performance for 229.95 + shipping and I'm glad to say my problems are gone.

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1990 Iroc convertible,305 tpi,Black with black leather interior,lowered,Taylor 8mm wires,K&N's

 

Mine is doing the same thing right now and Rich told me the same thing you guys stated above. I borrowed a friends digital meter but I'm not sure how to test each injector? Does the key need to be on without the car running? Does the car need to be running? What's the correct way to do the test? I went through the archives/FAQs and no luck. Thanks, Jeff

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1991 G92 Auto L98 - 3.23 71,000 miles

BBK 52mm Throttle Body, Ported Plenum/Runners, Edelbrock TES Headers (JetHot coated),
Dual Cats, American Thunder 80 Series Catback,Accel Wires (8.8mm), 160 Thermostat, TPIS AFPR (48psi),K&N Air Filters.

Rebuilt 700R-4. Thanks "Transfixleo".
1st time at the track, guess I should learn to launch right.

60ft: 2.15
Qrtr: 14.20
MPH: 98.49

<A HREF="http://
http://www.geocities.com/ssgtmcmichael/.html" TARGET=_blank>
http://www.geocities.com/ssgtmcmichael/.html</A>

 

Disregard previous post. Just got back from pulling off caps on the injectors and checking each one. Six of them gave me a reading of 16.2 to 16.3. One gave me a 11.3 reading and another gave me a 13.4 reading. At least I know the problem now. Guess I'll be ordering 8 new replacements from Rich. Any suggestions on the best ones to get from Rich?

 

Get the 23# Accel's. That's what I just put on and my car starts up like you wouldn't believe now.

Bob

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350 TPI, 700R4(rebuilt), K&N's, MSD 6AL, Headers, Flowmaster, 160* stat, airfoil, MAF screens cut out. 13.88 @ 101.18 mph