Stumbling still...Thoughts?

[Paul Workman]

Thanks, Tom.

I appreciate you taking the time to go over some of these items.

I Ω'ed the injectors cold - all read about 12Ω w/in .2-.3. Don't apologize...Should I Ω them hot as well (wondering 'out loud' as it were)?

The EGRs...I'll have a look. Good point.

One other item I just remembered...On a couple occasions, after backing off the secondaries - between gears - and accelerating again, I noticed a loud howl like the sound a 4-bbl carb makes when you stand on it - like the LT5 makes when the secondaries are open at WOT. There was a distinct loss of power. Backing off entirely and back on w/o calling the secondaries, and it sounded normal and power was back up to normal, and when calling the secondaries again, everything was normal. Something is sticking, and it screams "mechanical!"

There's only so much I can do w/o taking the top off. I was hoping to not have to do that until I was ready to powder coat the top end. But, then again, this is as much a familiarization/learning exercise for me as much as anything, Changing plug wires would require taking the plenum off anyway, I guess.

Well, I'll check the EGRs and we'll go from there.

Thank you and Jeffvette and the rest for your hand-holding. Honestly, I'm not new to mechanicals or electronics by a long shot. But, I've learned long ago that knowledge is power, and a lot cheaper than bulling in and phocking stuff up. After all, the LT5 is definitely different from the SBCs I'm used to!! So, I'm glad to take advantage of the expertise on this forum. I'm having a ball pouring over the FSM. (The only problem is it takes a long time to look something up b/c I keep getting sidetracked by discovering info on other things I had questions on...[sigh].)

I'll keep plugging away, with y'alls help, and let ya know what the final solution is.

P.

[32valvZ]

Hey Paul,
I love your posts. You say just what I want to say sometimes, only more eliquently......I am on the same page as you as far as my familiarity with the sbc. I have rebuilt many & ported iron heads at home etc. The LT5 makes me feel like a moron sometimes. I lift the hood, look allaround it, get mezmerized by its beauty, then close the hood again!!

Seriously, the guys who have been around these engines say theyre a piece of cake......like a reg sbc to us. I hope sometime to have the same confidence on my LT5 as some of the "pros".

I do remember reading in Haibecks write-up that the injectors should be checked with a hot engine. Thats how I did mine.All mine (primary & secondary) checked out between 13.7-14.0 ohms

I'm getting closer & closer to pulling my plenum as well. Maybe we can console each other on the phone while working in our garages...

[Pete]

Originally Posted by Paul Workman

Thanks, Tom.

I appreciate you taking the time to go over some of these items.

I Ω'ed the injectors cold - all read about 12Ω w/in .2-.3. Don't apologize...Should I Ω them hot as well (wondering 'out loud' as it were)?

The EGRs...I'll have a look. Good point.

One other item I just remembered...On a couple occasions, after backing off the secondaries - between gears - and accelerating again, I noticed a loud howl like the sound a 4-bbl carb makes when you stand on it - like the LT5 makes when the secondaries are open at WOT. There was a distinct loss of power. Backing off entirely and back on w/o calling the secondaries, and it sounded normal and power was back up to normal, and when calling the secondaries again, everything was normal. Something is sticking, and it screams "mechanical!"

There's only so much I can do w/o taking the top off. I was hoping to not have to do that until I was ready to powder coat the top end. But, then again, this is as much a familiarization/learning exercise for me as much as anything, Changing plug wires would require taking the plenum off anyway, I guess.

Well, I'll check the EGRs and we'll go from there.

Thank you and Jeffvette and the rest for your hand-holding. Honestly, I'm not new to mechanicals or electronics by a long shot. But, I've learned long ago that knowledge is power, and a lot cheaper than bulling in and phocking stuff up. After all, the LT5 is definitely different from the SBCs I'm used to!! So, I'm glad to take advantage of the expertise on this forum. I'm having a ball pouring over the FSM. (The only problem is it takes a long time to look something up b/c I keep getting sidetracked by discovering info on other things I had questions on...[sigh].)

I'll keep plugging away, with y'alls help, and let ya know what the final solution is.

P.

This sounds like a collapsing intake duct.
Do a search,i don't know if Mark Coplon still selling the reinforced ducts.

Pete

[tomtom72]

Holy smokes Pete.....never crossed my mind...

I spent so much time at the net reg site before I got my car that I did a lot of the corrections listed in the common issues section even before my car saw pavement under my ownership.


Paul, I have a b/n duct that I never used. If you wanna try this out I'll send it to ya & I'll dig out the bill & you pay me what it cost if you want to keep it. I never used it as I did a "dryer vent/exhaust tube" fix to my OEM soft as all get out duct...I called Mark C & he said "send me your's & I'll sleeve it"....well I bought a spare from one of the vendors, CC or MAMW or Eckler's to send to Mark C. I never did it because my "hardware store fix" worked so well & who sees the inside of the duct anyways??

Tom

[Paul Workman]

Originally Posted by Pete

This sounds like a collapsing intake duct.
Do a search,i don't know if Mark Coplon still selling the reinforced ducts.

Pete

In the words of Artie Johnson (Laugh-in): Veddy intorestink!!

(Yeah, yeah...I've really dated myself now, huh?)

Thanks for that. I noticed those things are pretty soft, huh?

P.

[Paul Workman]

Originally Posted by tomtom72

Holy smokes Pete.....never crossed my mind...=D>

I spent so much time at the net reg site before I got my car that I did a lot of the corrections listed in the common issues section even before my car saw pavement under my ownership.


Paul, I have a b/n duct that I never used. If you wanna try this out I'll send it to ya & I'll dig out the bill & you pay me what it cost if you want to keep it. I never used it as I did a "dryer vent/exhaust tube" fix to my OEM soft as all get out duct...I called Mark C & he said "send me your's & I'll sleeve it"....well I bought a spare from one of the vendors, CC or MAMW or Eckler's to send to Mark C. I never did it because my "hardware store fix" worked so well & who sees the inside of the duct anyways??

Tom

Well, hot damn! (And, thank you very much!) Love this board! But, among some of my other talents, I can do some interesting things with sheet metal - built manifolds for heating and air sytems a "few" times. I just might take you up on your terrific offer, but now that the (one collapsing flex intake tube) problem might have been identified, AND the cost of a foot or two of aluminum flashing is about nill, I recon I could sleeve the sucker internally, and probably smooth the air flow to boot! (That accordian shape has to be hell on air flow characteristics. Who knows...I might make a few spares for other folks to try)

Lemme get back to ya on that. (I really like your hardware store approach!)

As somebody said, these cars are up there in years, and I have a feeling I have a plethera of little items that are contributing to the over-all characteristics. Oh, there's nothing that is constant...Just a bunch of what appears to be un-related and mostly intermittent nags. After years of trouble shooting rifles to peak their accuracy for competition (another hobby of mine), I've developed a set of things I do to them before I ever take them out for the first time - curing a host of common issues whether or not the issues initially exist - being easier to just "overhaul" certain things than discover them one at a time. I have a feeling some of the folks on this board, certainly the pros, have developed a set of routine "dos" that are applied first. Then, if something else needs attention, it sypmtoms are not clouded by other niggling contributions from some other problem(s).

Well...Rambling as usual here. If I have no luck with the hardware store solution, I may take ya up on your fine offer!

On my way to "ACE" and to get a vacume test set and see what a set of gaskets is going to run me for the plenum (gad!).



P.

P.

[guinnessdood]

Funny you mention the sheetmetal. That's pretty much how the Coplon ducts are made...only Mark used stainless inside the duct. O have one on my car...works great and looks OEM.

[tomtom72]

Well hot dang....a tin knocker too!

Okay on my dryer fix....the 8" stuff is what I used...ya know the garbage 18 ga stuff comes in 2' (?) sections, and it's flat & ya gotta roll & hook the seam? Well after I cut it to the lenght for the duct, and inserted it, I found that I could squash it in the middle. I took it out & used a joining plate for wood framing...ya know same hdw store ....it was long enough to bend two tabs for feet/mounting points, opposite of one another ofcourse ....stand it up at the mid point of the duct and I used peanut screws from the outside of the sheet metal with a bit of red loctite....viola, instant air duct support courtsey of backyard/redneck technologies, INC.


Tom

[bradslt5]

back yard fixes are what i love about hotrodding . when one finds a simple no cost fix its like xmas allover =D>

[Paul Workman]

Originally Posted by bradslt5

back yard fixes are what i love about hotrodding . when one finds a simple no cost fix its like xmas allover =D>

Oh, hell yeah! And if that air foil thingy is good for 5-10hp gain, then the smooth air flow afforded by the smooth metal ducting should be worth at least 25 hp, no? I'm kidding!

But, yeah. Sometimes there' such a thing as "over engineering" a problem. This solution is not visible and does it's job. Hard to beat that!!

P.