Need Dual Holley tuner

[Michael C Henry]

I'm out of my element here. I've done and checked everything I know to do.Ten minute drive and the plugs are pretty well fouled .
Know someone in the Tacoma area that does this?

[kidcobra]

Give Scott Johnston a call at RHP AirFlow Development.
253-988-6648
He did a powertune on my cobra and is a wiz at the stuff.
And he is just off of Portland Ave and 512
Matt

[Michael C Henry]

I talked to Scott and dropped in on Turbo Technology. They think it may be ignition related.I have an all Mallory system. 38 series distributor,#29440 ProMaster coil ,HyFire VI 685 CD box,# 700 balast resister, 29351 active power filter.and Pro Sidewinder plug wires. Anybody experienced with this stuff?

[kidcobra]

I had one hell of a time dealing with my Mallory set up. I spoke with a good friend of mine Animal Jim and he said junk it and go with a MSD set up. So I did.
From what I was told the Unilight Dist was not made to handle a lot of hard take offs and or off road runs. When I dropped in the new MSD dist I noticed a hugh differance. Before the old dist would jump the timing around more then it should and with the new MSD it is right on the money all the time.
I didnt really noticed any major changes when I swapped out all the other componets to MSD. So I would call Scott again and see if he can put your dist in his machine and get it dialed in for ya. It just might be just out of wack or not advancing properly.
Matt

[Michael C Henry]

My thing is this car ran .It had a problem so I tried to improve this ,then that . The Mallory system in the car Mallory 38 series distrib ,29440 Pro master coil,and an old HyFire IV CD ignition box were there .It had an knob adjustable rev limiter built into the dash that I thought was working .I descovered that it only was meant for distributor and coil ,no CD. So I descided to change to a new CD box that had a programable rev limitter. It came with many features that I will never use but I was happy with two programable rev limits. and a programable automatic start retard.It was supposed to take less electrical power to operate and could handle heat better. Ah heck! the decal was gone from the old HyFire IV and a correct one wasn't available. Tomorrow I'm goin to try new NGK plugs and bypass the balast resister.I'm getting tired ov changing the spark plugs.

[kidcobra]

Okay Mike
What did you change to make it run not so good? Did you replace your dist??
If it is one tooth off you will be way out of wack.
Matt

[Michael C Henry]

It felt like I had made a difference so I went to my sons house and took him on a few close trips. It turns out the wire that I disconnected was the resister starting bypass . less than ten miniutes of driving and a few cool downs.Went to get on I5 at S56th north bound. It started to miss at s 74th , so I was getting off at 512. The missing got worse trying to nurse it home. Idle was ok but driving or accelerating was rough and jerky . I have installed new NGK spark plugs (Removing material with a rotary file around #6 hole because it would hold my socket when I installed a plug) ,grounded the box itsself, checked programing modes and made the three wire harness that supplies the distributor with power filter inline a little longer so I can elliminate the filter if I desire to.The balast resister is bypassed now . I'm waiting for better weather conditions to test. If this doesn't cure it then I want to get the car to a facility with testing equipment and maybe a dyno roller to determine if the fouled spark plugs caused the missing or the ignition system causing a miss fouled the plugs. and see if it is a time from start thing .I can't beleive it is temp related I'm running without a hood.

[W2zero]

Ever go to Bill's Dyno Tune on south G street? It's across from Lincoln High School. They Steve's car on the rollers and tuned his dual quads to perfection.

[SCOBRAC]

Do I dare ask what power valves you are using? What is the manifold vacuum at idle? If the vacuum is equal to or less than the power valve number at idle you need to use a lower number power valve.

If lets say you have holley 1850's which come stock with a 8.5 power valve but your dual carb monster idles at 5.5 inches of vacuum, you need a #3 power valve. Try to keep the power valve 2.5-3.0 points below the manifold vacuum at idle.

The other big problem people with big cams experience is the idle transfer slot is completely exposed due to the amount of air required to keep your car running. You may actually be running on the cruising circut all the time or most of the time.

Address the power valves first, always one thing at a time... Let us know what you find then we'll correct the transfer slot condition.

[Michael C Henry]

I have 4.5 power valves ,carries 9-10 at idle I can actually accelerate slightly without droppnig below 9.
I'm now questioning if it is the fouled spark plugs that are causing the miss = carb problems or is the miss causeing the fouled spark plugs = ignition problems.
It has only crapped out while driving , usually within ten minutes from starting the actual drive . No hint at idle or in neutral. I do a warm up to get oil temp before I start getting into the throttle . The carbs may need some finite tuning still but they look great they are dry and not drueling gasoline any longer.the carbs dont fume once the engine has stopped either.I have checked the powervalves( not blown or leaking) and the backfiring happened months ago before I had the carbrueters redone . For the next test, I have now bypassed the new balast resister .Just received that message from Mallory teck. " Balast resister is used only when eliminating the CD box with the shorting plug "so car could be driven with just the distributor and coil.system gets full voltage with box in operation . that wasn't made clear in the wiring diagrams I read . I'm now waiting for my neighborhood towing service to be home waiting by the phone just in case.

[Michael C Henry]

I bypassed the balast resister as directed by Mallory tech support.System is getting full voltage. after a lot more driving than I was able to do before I did take the car onto I5 then to the Bridgeport exit. I stopped at Bud's machine shop for a short show and tell .I left the car idleing. When I leave I get a block away and the car starts the missing and stumbleing. So home I go, limping. I get the car into my garage and proceed to bypass the Mallory HyFire VI 685 ignition box using the supplied bypass plug and rearange the wires at the balast resister so the resister is suppling power and It is running on just the Mallory 38 series distributor and mallory 29440 ProMaster coil. worked great. so even more test driving..No problem .I've used almost a full tank of semi pressious 92 oct gasoline. So I bought 14 gal of fresh 92 oct gas and started driving some more.I have more miles and time on this test than any test before. I'm satisified that the box is to blame.The carbs may need a little finite adjusting. I'll be sending the box in for replacement or repair.
So it turns out that the miss caused the fouled plugs

[Big-Foot]

Mike - that's GREAT news!

Congratulations!!!!

[Michael C Henry]

So here I am again waiting for another thing to be resolved.Leaving the hood off will make the box R&R easier.Wonder what hoops Mallory will try to make me jump through to get it serviced or replaced?It's new very low miles little time and a big pain in my a*(

[Big-Foot]

It's been a couple of years since I have had to deal with Mallory's repair department, but the guys there did their best and it all worked out.

[Michael C Henry]

Sounds like Summit will just send another ignition box. They received my old failing unit the 28th and new units are on the shelf. Summit was't verry concerned about what the old unit was doing . I should have a new ignition box by a couple of days after the first of the year.I realy think I have it kicked now it starts and runs without hesitation. A year ago I thought I was almost where I am now. Ready for interior and top. I have learned alot about Holley carbs during this ordeal.

[Big-Foot]

Clouds and silver linings... Maybe a shred of truth to that!