Major Engine Miss above 3K

[Bob Eyres]

Thanks again Paul, I'll post how it goes when I find the $800.00 or so to get the job done.

[LGAFF]

Bob I am going to switch over to a different primary injector so I can run shorties....my accels are 2 years old....maybe we can set you up at a reasonable price if you would interested

Unless I forgot the primaries and 2ndries are the same

[rhipsher]

Bob this is what I suggest. With full power on run the car up to 7k. The car won't like it but I guarantee it will throw a code. I do agree that you should replace the original injectors but if it was bad injectors the car would run horrible all of the time. Not just above 3K or when the power key is on full. I had just two injectors go out on me and my car felt like it was only running on 4 cylinders and was shaking badly. Force the car to spit out a code and I'll bet you'll see code 61. Also if you want to know the poor mans method of checking codes I posted a video of how in the how to section. Vettmed could link it up.
I found it. here you go. http://s301.photobucket.com/albums/n...t=codes001.mp4

[Paul Workman]

Originally Posted by Bob Eyres

After sitting for a few months my 91',(60Kmi.), Has got a serious miss in the secondary induction system.

It looks like there's a plenum pull in my future. Any way to avoid that?

TIA, Bob.

Something I missed earlier... When you say "sitting for a few months", are you saying the engine was never started in the interval?

My reson for asking is this: I'm apparently a slow learner, or a thorough scientist (I prefer the latter ). I have experienced the result of fuel becoming gummy, and forming a varnish in everything from injectors, to carb jetting, to float seats.

I've got a fleet of 8 gasoline motors on "the ranch" that are idle during the winter. Over the years, I’ve experienced that if the fuel is not at least "stabilized" every winter, and/or the engine started at least once a month, it is not a matter of will one of them be gummed up but how many! And, I can report that when using a stabilizer (I've used Sea Foam and Sta-bil with equal success) and once a month starting and warm up, I've had ZERO issues with engines having treated fuel. In fact, it seems almost a given that if I don't dope the gas and don't start it a few times over the winter, small engines especially it is practically a certainty they will NOT survive!

Well, I'm not saying gummed up injector(s) is your problem; more likely the fact that alcohol has "had their way" with your injectors...OR both. But, as Marc said recently, "...it is a 100% certainty (that the pre 93 injectors will FAIL in the presence of alcohol)".

Most of us are methodical troubleshooters by necessity; we don't just change (semi-rare/expensive!) parts until the problem goes away. But, in the case of the injectors, this is one item that needs to be cleared off the deck before troubleshooting further, IMO. Sooner or later (if not already at hand) you'll be under the plenum anyway - it is "a right of passage" to being a ZR-1 owner! Fortunately, it is no big deal at all, AND you have a chance to do a little R&R of gaskets, starter solenoid, etc. "while you're in there".

Well, it is practically moot whether it is gumming or alcohol, if stock, da bastards needs ta come outta there. (BTW, mine were initially replaced by the dealer prior to my taking delivery. The issue was the injectors were replaced at a Chevy dealership with !@%#@* NOS injectors. They lasted 3 years before some went south - discovered when Marc was tuning my motor a year and some ago.)

If (like me) you wanna verify the injectors have suffered from the alcohol, warm the engine up good and then measure the resistance of each. Stock injectors should be ≈ 12.5 Ω, ± 1 Ω. LESS than that precedes issues, and by the time resistance gets to 8Ω or less, there is potential for the cylinder running lean, and all the attendant bad chit to go with it exists too!

Call Jon. Put it "on the card", and be done with it!

P.

[Bob Eyres]

Thanks Paul, and all you guys, for sharing the benefit of your experience. I'll probably go with the Accel's from Summit.
In 21 years the plenum has only been pulled once, not by me. Too much other work lately to tackle it, but that earns the $$$ to get the parts.
I might even get the DVD that Marc made on the plenum pull.
Whatever, if I get into trouble, I'll be back here looking for help.

Thanks again, Bob.

[bldavis11]

Originally Posted by Bob Eyres

Thanks Paul, and all you guys, for sharing the benefit of your experience. I'll probably go with the Accel's from Summit.
In 21 years the plenum has only been pulled once, not by me. Too much other work lately to tackle it, but that earns the $$$ to get the parts.
I might even get the DVD that Marc made on the plenum pull.
Whatever, if I get into trouble, I'll be back here looking for help.

Thanks again, Bob.

Bob, et al.

Accel #150821 are available on Amazon as well. Total set of 16 for about $545. Hope this helps!

Ben