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Discussion Starter · #1 ·
Hi guys.
I'm back working with HEI again.
I need some input on what is the initial setup (is it the same as the original 8 BTDC from factory setting)?
My setup is #1 @ 6 o'clock and 8 o'clock for the vaccum advance pt.
It's firing OK but when I'm driving, aroung 600-800 RPM it hesitated and OK again after that.
I checked Larry's page for possible fix but no go.
Is there any other HEI page out there?
Thank a bunch.

Dody

 

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When you say "driving" .......at 600-800 rpm ...... you've got to mean "starting out off of idle"......
I've swapped HEIs out in older chevy motors and experienced some coast/power hesitation which required a "recurving" of the distributor ...... but off idle hesitation?????? You did plug the vacuum advance for initial timing setup didn't you?...and you're sure that you didn't knock off a vacuum line somewhere else in the process? Unless the vacuum advance is going to physically hit something that will prevent you from turning it for ajustment ....... and your plug wires are going to the proper respective cylinders.........you should be able to have the distributor in any way you want .........just as long as when #1 is up .........the rotor is pointing to the post that #1 plug wire is attached to.
Just a few thoughts.
GeeAea

 
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Discussion Starter · #3 ·
Dody,

Fill out your profile so people will no what vehicle we are talking about. What year is your jeep?

If it is 82 or up then plug the vacuum advance and set the timing with the engine at 1600rpms. 8-9 BTDC is a good starting point. Try using a different type of vacuum.... there is nothing etched in stone about what is better - manifold vs ported.

Keep us posted.

LarryM
85 CJ7, 350TBI ,T19 4spd
'00 TJ Sport
 
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Discussion Starter · #4 ·
It's 81 Jeep CJ7, Weber carb.
Well, I meant both driving and during idling only between 600-800 RPM (or when accelerating at low RPM).
I did plugged the vaccum just like any other dist. setup.
I use Weber so there's only 1 direct vaccum line to the HEI.
One thing I wonder is setting the gear one tooth back like Larry mentioned but does it matter (since you can rotate the housing anyway)?
Also I have that adjustable vaccum canister system mounted on the HEI.
So I wondered what's the bug?
Thanks

Dody

 

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I just finished the HEI installation on my 84 CJ-7 last week, and I also have the Weber (k15538 DGES).
Here's what I came up with. I use 87 Octane, and live 750 ft above sea level so YMMV. I started with 10 degrees of advance with the vacuum line plugged. I used the Crane Cams adjustable vacuum advance unit, and ended up with 2 blue(heavy)springs for the cent. advance. I then had to turn the adjustable vacuum advance 6 turns out. Just about perfect!

 

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I also bought a recurve kit and was wondering where I would want the vacume advance to start? some new springs came with the adjustable vacume advance kit too but I didn't use those....

 
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Discussion Starter · #7 ·
I have the advance curve chart on my webpage...it shouldnt be too different for most 258's.

LarryM
85 CJ7, 350TBI ,T19 4spd
'00 TJ Sport
 
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Discussion Starter · #8 ·
Now that you mention it, my 89 Wrangler with HEI has that same tell tale 600-800 miss, haven't noticed it until you mentioned in your post. I am not sure how to fix the problem, which way to go with recurving the distributore etc.

Symptom: 1st gear rolling let RPM drop below 800 then punch the throttle. It miss like a big dog for a few seconds. Once it gets to about 1000 rpm it goes like a rabbit. This is not an accelerator pump problem at all. The post about heavy weighted springs may be the ticket, but why??

TIA


CB
 
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Discussion Starter · #9 ·
I still am having problem with the way it runs (not that smooth for stop and go traffic).
I tried the 2 heavy springs (blue colored) and 6 turn counter clockwise for the adj. vaccum and still ran like crap.
The weights on my HEI were rusted so I sanded them down (didn't know if it matter).
I will replace the weight and see what will happen.
In theory, HEI should work OK with the right gear (I believe it's out of 360's distributor).
So, I'm just gonna try until it's working right.

Dody

 
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Discussion Starter · #10 ·
I haven't purchased the Vac Advance kit yet, I would be interested in hearing how it turns out on your ride. So far my miss hasn't bothered me- even in traffic. I generally keep up above the 900rpm mark anyway. But for rock crawling or slow trailing I can see where it would be a challenge.

After thinking about it for awhile, I suppose the only thing to do is to change spring weights and vacuum advance until you figure out if it is not advancing enough or it is advancing too much off of idle. I love the way it runs in general it is 10 times better than the old setup....keep us posted. BTW I haven't disconected or disabled any of my other emmissions equipment, just tapped the HEI dist into the switched 12V line going to the ignition module. I am running a Carter BBD stock on a 5spd.

Later,


CB
 

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I am running the HEI and a weber 32/36 on an 88YJ, automatic. I had the crane adj. advance, but took it off - too many adjustments. I use the stock vac advance can, one heavy spring and one light spring to flatten out the advance curve, and it doesn't ping at any RPM, I have the advance off of manifold vac, she takes off nice from idle, no skips or misses, goes great right up to high RPM (on the highway with 4.10 gears and only 31s for the winter RPMs are a bit high). I am very happy with the whole setup. Oh, and my 258 is only about 3 months old.

Jsut what works best for me. Everyone's setup seems to vary...
Good luck
Pete

88YJ,4"susp,33"BFGMTs,9000#winch, hm swing out TC/HL mount ,258,999,4.10,weber32/36,GMHEI.
 
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