Found a bad/low flowing injector L98
 

I discovered that I had a few lower injector O-rings that were leaking vacuum a while ago and I ordered a new O-ring kit. I decided today would be the day to pull the injectors, flow test them, ultrasonically clean them, and flow test them again and reinstall them with new O-rings.

In the course of this process, I found out that I had a single injector that was flowing about 7cc to 10cc less fluid at 40psi for 30sec than all the others. It was the injector that feeds the #6 cylinder, and it also was one with a leaky lower O-ring. The car ran pretty decent other than when I would first start it cold, it almost felt like it had a dead hole but would smooth out as the engine warmed. This injector and the O-ring leak was probably the cause of that.

Got online and saw that Autozone sells the New replacement Lucas Injector so I went ahead and ordered one and it will be here tomorrow.

The machine I own is an older ASNU 001 Cleaning Machine. It was a garage sale score a few years ago for very cheap and I spent about $300 on it to get it back to fully operating condition. I've probably made 10 times that amount cleaning injectors for a local auto shop.

Here is an overall view of the equipment I use.

Here is the first go around of flow testing before cleaning.

Cleaning the tips after cleaning the bodies.

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Results after cleaning. Not much change meaning that they weren't even dirty to begin with. I've brought quite a few injectors back from the dead with this machine though.... GM Multec injectors have been the worst to clean so far as it usually takes multiple cleaning cycles for 1-2 out of 8 to get them flowing correctly again.

I ran the low flowing injector through 5 cleaning cycles and there was zero change in flow meaning that it has an internal mechanical problem.

The thing that sucks is having to wait for a new injector. It is Vette driving weather in Western Washington today and I was looking forward to a sunset cruise today!!

A garage sale had that cleaner? What sort of garage?

How many miles since the last clean? I'm curious since I usually have way more than that after 3 or so years in the C4 or 100K on other gas cars. Or more precisely, the change is much greater. That I have 42 pph injectors might be something since they have larger volume so it might cause a bigger drop if it gets plugged.

Why did you change just one injector? Were they newer?

How do you clean the Multec injectors since they say you are not supposed to have any solvent in it for fear it might corrode the insulation of the coils? Or is the cleaning solution not considered a solvent?

The gals father passed away and this was amongst some stuff she cleaned out of his storage unit. It was in pretty poor shape cosmetically and functionally, It had been allowed to sit with the old flow solution in it and it had dried up. Required complete disassembly and cleaning, new filters, new seals, etc. ASNU still sells all of the parts for it which was great.

I also bought a Ferret 40 Charging system analyzer super cheap from her as well. It needed a pair of replacement LCD screens that came out of China for about $8 total.

Couldn't say how many miles since the last clean, or that they have ever been cleaned. Car has 122K on it.

I saw no reason to replace any of the other injectors, they passed multiple tests while flowing at different RPM's and different MS. They aren't perfectly balanced but OEM injectors rarely are.

The cleaning solution isn't a solvent..... that is unless you consider Windex a solvent. The sales guy at ASNU said that is basically what the "Blue Goo" solution they sell is. I use a 50/50 mix of Simple Green and Water in my larger U/S Cleaner.

Jared

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Stopped by Autozone on my way to work and picked up my replacement injector. Just got home and got it set up in the flow bench to see the difference.... and the difference was 10cc over 30sec at 40psi. The other 7 injectors are 60 to 63cc.

Before I left for work I also media blasted the other 7 injectors and got a fresh coat of semi gloss black paint on them.

Hopefully I can get it all back together before I have to leave for work tomorrow.

Jared

Got it all back together and when I fired it up I immediately noticed how much smoother it was running.

One more project down!!

Jared

dam, just caught this thread, I just swapped out my stock injectors a couple months ago, you could of had my old ones, with that machine probably could make most of them like new again

Assuming you had anything but Multec injectors, sure. If you did and those looked like Multecs, I wouldn't since they chain me to using a few gas stations. Now you can go anywhere.

op is local to me, I was saying he could of had my old ones instead of ordering a stock replacement like he did. Im happy with my bosch

As long as they are Bosch I would have no issues using them again.

My injectors were Lucas, and when I cross referenced them it seems they were only used in 87-88 in the L98 Vette, Camaro, and Firebird.

I certainly appreciate that you would have made the offer though!! Luckily enough I got a new one next day.

Jared

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edit, wtf how did this post end up here

You probably scrolled down to post and you wound up posting in a "Related Thread"

I went into my Control Panel and turned that stupid "Related Thread" feature off.

Jared