1997 Chevy Silverado

It's good to hear that you used OE tuneup parts. I'm going to suggest two more: AC Delco cap and rotor. Your engine has a funky distributor cap that I can only assume was designed using the 'style over substance' method. You will notice that the plug wires exit the cap neatly to the left and right sides, unlike on conventional caps where each wire is equally spaced around the diameter of the cap. Cool, huh? The problem is that to make the cap look like that, most of the cap's spark plug wire terminals aren't anywhere near where the rotor "fires" their respective cylinders. If you inspect the top of the cap you will see the molded-in routing that dictates which terminal is fed by which clock position on the distributor.

The real damning evidence here is that cylinder 5's plug wire enters right where the cylinder 7 terminal is inside the cap. It's the same for the cylinder 4 wire and cylinder 3 terminal. Now you can see why an ignition crossfire is so likely, and it is also likely that something like this would be intermittant, setting the misfire codes in no particular order. The 4/3 combination is *really* close on the cap, as is the 7/2. There are many problem areas where ignition crossfire is facilitated on this cap, so you could conceivably see more misfire codes in the future.

Try the cap and rotor for ~$50US and see if that takes care of it.

Toyota MDT in MO

Thanks, but there is no Cap....it is individual coil packs for each cylinder. I'm quite certain now it is the fuel pump.

Comboverfish wrote:

Then it is not a 1997 Silverado with a 5.7.

Geez, you ever get the feeling you just wasted 200+ words?

Is a 5.7 litre different in Canada than a US 5.7 liter? Hmmm...

Toyota MDT in MO

I, for one, do not understand why Comboverfish's comprehensive response--obviously laborously created to help one specific person out of his plight--called for or deserved such an insulting reply. His responses have pretty much all been unselfish sharing of real-world experiences, not mere quotes from repair manuals or highly theoretical guesses. He even admitted having been 'off the mark' about his analysis of an unusual vehicle when he said, "Geez, you ever get the feeling you just wasted 200+ words?"--obviously a self-deprecating remark and an apparent apology. Please continue offering your expertise, C-Fish, as many of us benefit from and appreciate your ideas. s

I agree, SD. Comboverfish is a professional and a highly knowledgeable contributor to this site, as are several others, and I would hate to see them get fed up with this sort of response.

Thanks, H. Now I'm blushing...

:) Toyota MDT in MO

Very kind of you to reply in this manner, Sdlomi2. I appreciate your contribution to this group as well.

I actually meant that the OP wasted my time by posting incorrect vehicle info, or not enough info to give a "correct" answer. If he really had a 1997 Chevy Silverado with 5.7, and I don't care what trim level, Suburban or truck, short bed, long bed, whatever, then he would have the Vortec with a distributor -- no coilpacks. His description of which pairs of cylinders were misfiring was a classic case of cap crossfiring based on the design of that tried and untrue cap design. Of course I had to find a picture of one online to verify which cylinder pairs were most suspect... Neil even replied that the OP must have a distributor if it is a 97 5.7. He lives up north and knows a thing or two about Canadian spec vehicles, so I figure his to be a well considered reply given the OP is somewhere in Canada (apparently). Now if the OP had a different engine or some aftermarket ignition system (not likely) it still should have been mentioned.

Enough soapboxing, I just heard the bell ring.... The decision... TKO! I'll take it... :)

Toyota MDT in MO

"General" wrote in news:1169341266.793872.106090 @s34g2000cwa.googlegroups.com:

97 /5.7 L/coil over plug?......not here in the land of plenty. now up there in the frozen tundra they may have built some bastardized 97 but down here it wasnt until late 99 when they switched to the 5.3 design......since you do have coil over plug ign. you should know...*coils fail intermittently*. yep. all the time.......i see it more in ford than gm but ive replaced many of single fire coils in the new trucks also. if you truley suspect the fuel pump a simple guage will tell you if pressure is not adequate when symptoms appear. if you decide to replace pump make sure you get one made in USA. those french pumps only work part of the time and surrender under pressure!

So what does a timing light tell you?

--scott

Good call on the stuck poppets. Shame on me, I've been using compressed air.

100% success rate though... (just ask my brother in law who's too cheap to use a bottle of Techron a couple of times a year.)

Hey Neil,

Do you have a homemade adaptor for the schrader valve, or ? What kind of PSI gets the job done without being dangerous? Which scanner do you bidirectional the solenoids with, or ?

Thanks for your time,

Toyota MDT in MO

I made an adaptor out of 3/8" steel line to fit the fuel line connection (O-ring) either at the back side of the intake manifold or at the fuel filter, the Mastercool flaring tool:

the GM O-ring fitting, the nut is available thru Edelmann as part number 109600:

100-120 PSI

I use my OTC injector balance tool:

see if the AE can command injectors on next time a Vortec comes in... This is all done with the engine off, if you block the throttle plate open, you can actually hear when the poppet un-sticks by the sound.

Watch your e-mail.

"Comboverfish" wrote in news: snipped-for-privacy@m58g2000cwm.googlegroups.com:

Please ignore the vomitous expellations of the anti-American Kommunist Kanadians.

Anti-Americanism is Canada's national sport. You'd have to live up here to understand the insanity. If you didn't see and hear it first-hand (every day), you wouldn't (couldn't) believe its pervasiveness, fury, idiocy, and banality.

Canada is America Lite: Tastes great, but not nearly the same thing. And don't the Canadians know this. And don't they resent the disconnect, with a passion!

I'm kind of surprised that you got one of these, but with all of the various drivability issues you tackle it has no doubt paid for itself in convenience.

I can't imagine Jay would leave that function out.

Unless your engine runs on air, then by all means, let it run :)

You got it.

Toyota MDT in MO

Indeed. I've had it since the late 80s and it sure has come in handy.

Did you buy AE yet?

I mainly mentioned that for the benefit of the OP.