Holley Guru's step up

Discussion in 'General Ranchero Help' started by Doc76251, Jan 29, 2019.

  1. Doc76251

    Doc76251 In Third Gear

    Messages:
    203
    Location:
    Virginia Beach, VA
    So I've been futzing with my carb since I got the car (Holley 600 CFM, Street Warrior, Electric Choke). The basic issue is that I keep getting backfires through the carb and/or a hesitation then go when I floor it.I discovered a great many things along the way.
    - I had transmission fluid in my vacuum line from a faulty trans modulator (replaced and fixed). Multiple vacuum leaks in the hoses (all replaced).
    - Secondary throttle was WAY out of adjustment (adjusted and fixed). No kick down linkage (waiting on a pay check to get a Lokar).
    - Bad coil (Replaced).
    - Changed spark plugs to E3 diamond fire's.
    - Checked resistance on plug and coil wires (all weel within limits).
    - Unable to check timing as my alternator is in the way and can't see the HB, I have adjusted by ear to the point that the backfire goes away but then my idle is so high that it slams into reverse HARD! At that point I have no adjustment on the curb idle screw (hot engine). Cranked up the curb idle screw and backed the timing off so that it idled still have occasional pop's and backfires and it is dog a$$'d slow off the line.
    - Final change was to replace the shooter. Momma got me a Trick Kit for Christmas, the carb had a 31 in it to start ( no brass horns) so I tried a 28 w/ horns. Car ran and choked with heavy throttle. OK. Tried a 37 w/ horns, didn't backfire or pop but was dogging off the line, no tire spin. So after all that.........

    What is the deal with the little brass horns? What do they do for or to the car? Why choose them over no horns? The one on the right came out of the carb, the one on the left with the horns was in the box. Don't have a 34 or 35 to test. (Edit to add: Sorry for the crappy pic, both are 31's)

    [​IMG]

    Given all the above, any suggestions, thoughts, tips, tricks, ideas?

    Cheers,

    Doc
     
  2. aquartlow

    aquartlow In Maximum Overdrive

    Messages:
    1,264
    Location:
    Summerfield Florida
    I have found the shooters with the "horns" helps get the pump shot to atomize a bit better by having it hit the side of the venture booster and/or have the majority of the pump shot be in the center of the venture bore when the airflow velocity is high enough that the pump shot doesn't actually hit the booster. I would recommend getting some #61-80 pin drills with pin drill vice that would allow you to open up the shooter's orifice size. Pull the alternator and get an accurate timing #, guessing will usually bring problems, re-install alt after getting/setting the correct ignition timing. I thought you had the carb all "figgered" out a month or so ago :confused:. Hope this helps
     
  3. Doc76251

    Doc76251 In Third Gear

    Messages:
    203
    Location:
    Virginia Beach, VA
    Yeah I had it running beautifully in the drive way. Took it out and it was dog crap. Made it go back to sounding like a top fuel dragster and she burnt the rear tires off but I couldn't get the idle below 1200 RPM. Now I'm back to sputter and pop with minimal timing in and a bigger pump shot. May need to add more timing and deal with the higher idle. Also want to play with the accelerator pump, I have it barely touching now if not a bit loose, mebby add a bit of tension........ My problem is that I only get to mess with it in infrequent spurts and usually after dark. Worked all day Saturday and had this past Sunday slated for Midnight work but had to open "Dad's Garage" to change two blown head gaskets on Jr's Subaru. Now we are moving into go fast phase of my project at work so mandatory overtime and weekend work are all but guaranteed for the next 3 mos. I gotta get this thing figured out by spring, Momma wants to cruze to Dumar's for ice cream this spring.
     
  4. colnago

    colnago In Fourth Gear

    Messages:
    412
    Location:
    Ridgecrest, CA
    First, I'm not a Holley guy (my '67 F250 came with an Edelbrock, so I learned its eccentricities; the 'chero has an Autolite 2100). But I thought I read that a backfire through the carb could damage something in the Holley (accelerator pump?). Are you sure that nothing has been damaged?

    Just askin',

    Joseph
     
  5. pmrphil

    pmrphil In Overdrive GOLD MEMBER

    Messages:
    828
    Set the timing FIRST, then attend to other stuff. You will chase your tail otherwise. You have to start at the beginning, and that's the timing.
     
  6. Hillbilly

    Hillbilly In Maximum Overdrive

    Messages:
    5,337
    Location:
    Winchester, TN.
    A backfire can damage the power valve diaphragm on both the Holley and the Ford carbs. With a damaged diaphragm you will never be able to set anything correctly. The usual signal of a bad diaphragm is having an over - rich fuel mixture at any rpm. Lock in your dwell and timing first then go for the carb or you are wasting your time. The Ford 2-V carbs are just the front half of a Holley carb, dirt simple if your rubber parts are in good order. Oh, ethanol crap fuel mixes vastly shorten the life of those rubber parts so start with known good parts so you don't beat yourself to death chasing simple troubles.
     
    PonyExpressRider and Dyno like this.
  7. pmrphil

    pmrphil In Overdrive GOLD MEMBER

    Messages:
    828
    Luckily he doesn't have to worry about the power valve - the newer Street (and race) versions ALL have anti-backfire protection built in.
     
  8. beerbelly

    beerbelly In Maximum Overdrive SILVER MEMBER

    Messages:
    1,727
    Location:
    Portland OR
    Every time I ever had backfiring, it was a timing issue.
     
  9. colnago

    colnago In Fourth Gear

    Messages:
    412
    Location:
    Ridgecrest, CA
    Come to think of it, I had backfiring issues on my 352FE, before the rebuild. Turns out that the heads had never been rebuilt, and the valve seats were all worn, especially the input valve on #1. Since #1 never sealed properly, I would get the occasional backfire from the ignition coming back through the intake manifold. You didn't say, but what's the health on the rest of the engine?

    Joseph
     
  10. Doc76251

    Doc76251 In Third Gear

    Messages:
    203
    Location:
    Virginia Beach, VA
    Overall condition of the motor seems to be pretty good. I haven't done a compression check on it yet but between the time that the new heads were put on it and now I don't think she's gotten very many miles under her belt. The original owner used to post here under "bseberle" and chatted often with another local guy "Fomoco8" The upper half of the motor had World Jr. Heads, Edelebrock dual plane performer intake, a mild Comp Cams 260H grind installed in 2007 along with the MSD 6A and billet Distro, FMX and shortened drive shaft with 3.73 LS gears (haven't been able to make both tires spin yet tho). There was another owner between "bseberle" and the young Marine I bought it from that had a little work done. The fella I bought it from had the car painted (nice 20' paint job), new wheels and tires and put the Street Warrior Holley on it (I have the Holley he took off ) as well as bought a bunch of spare parts that he didn't have time to put on but I certainly found useful. When I got the car it would backfire occasionally and cut off for no apparent reason when braking and turning at slow speed. I've done all the stuff I listed at the top and am seriously thinking about adding a timing indicator (bent wire bolted to the block) on the driver side and mechanically finding TDC to put on timing tape. All of my issues are at slow speed or launch. The thing runs like a raped ape above 40 MPH. I don't think the young Marine was much of a diagnostician but was more inclined to throw parts at it as I still have a brandy new fuel pump in the box of goodies. Right now it's too damn cold to work on it so I am concentrating a bit on finishing my custom dash and gauges since the original crumbled in my hands. This of course lets my mind wander......

    Cheers,

    Doc
     
  11. pmrphil

    pmrphil In Overdrive GOLD MEMBER

    Messages:
    828
    Doc, on the small block Ford there are 3 different possibilities of pointer positions. Instead of a bent wire (which WILL get hit and bent again :rolleyes:) how about getting another factory pointer or at least making one rigid enough to withstand contact. Then find TDC and file a mark in the damper (highlight it with tire marker) and use a dial type timing light to set it.
     
  12. colnago

    colnago In Fourth Gear

    Messages:
    412
    Location:
    Ridgecrest, CA
    "This of course lets my mind wander......"

    Yep, I know that one! This weekend, I was working on my heater core. Took it out for a spin, and the speedo was making a clicking noise. Looked down, and the odometer wasn't updating. So now I have a broken speedometer/odometer, AND my heater still doesn't work! Always something!

    Sounds like your engine is as physically fit as it can be. If it runs great at speed, but it hesitates when you floor it, then it sounds like your accelerator pump needs to be adjusted to give a bigger shot. If it's cutting off for no reason at slow speeds, check your oil for moisture. Long story short, on my 352FE, the PO had removed the PCV valve, and just had a breather cap. Since the gasses weren't being pulled out of the crankcase, it built up moisture. This caused the oil to get washed out from the pivot on my mechanical fuel pump, so when the eccentric pushed the lever down, the lever wouldn't return. No pump, no fuel. I put in a new PCV circuit, fuel pump, and oil, and my low-speed stalls never happened again.

    On the timing pointer, I agree with pmrphil. You can get new pointers on ebay for less than ten bucks. Mine was missing when I got my Ranchero, so I got a new one and painted on new timing marks, then double-checked my TDC mark with a piston stop.

    Joseph
     
  13. PonyExpressRider

    PonyExpressRider In Overdrive

    Messages:
    866
    Location:
    Sutherlin, OR
    DWELL (if applicable), Timing, Vacuum… My Holley 735 is a bear to set as well... but I have found it never hurts to have the Vacuum gauge on the Distributer Vacuum, while setting the timing and while messing with the carb... or just doing a tune up.

    might have missed it, have you checked syntrifical advance springs?
     
  14. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    8,472
    Location:
    Everett, WA
    PER has a point. With breaker ignition, you have to ensure that the points, breaker plate, centrifugal advance and vacuum advance all work in conjunction with each other. And only the points and vacuum advance require setting. So, start off with your dwell--it must be set before setting timing, as a change in dwell will cause a change in timing, but not the reverse. Timing will not change dwell.
     
  15. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    8,472
    Location:
    Everett, WA
    Disregard my last--I got confused, thought you had a Falcon Chero with an inline six, but you have a '77 V8 Ranchero...d'oh!
     
  16. Doc76251

    Doc76251 In Third Gear

    Messages:
    203
    Location:
    Virginia Beach, VA
    PER & Andy, I'm not sure if dwell is applicable as I have an MSD 6A ignition box and a MSD Billet Distro but your commentary leads me down the road of centrifugal vacuum advance springs. Somewhere in the past of that car was a catastrophic heater/coolant hose failure there are signs of it all over the motor as well as INSIDE the Distro.

    [​IMG]

    My intention was to get the car to launch and idle correctly in gear and then address the Vacuum Advance and springs as vacuum essentially drops to zero on acceleration so my vacuum advance is not immediately applicable.

    In saying that. Yes I need to figure out what my timing is so that I know how much I can put into it on the curve (as well as when and how much via the springs) my understanding is that around 34* ish is about max and the little rubber bushing limit the max so determination of the bushing size has to have a base line. On my slightly lumpy cam I am understanding that I may need more initial timing than the stock 12 - 15*.

    So I will probably pull the carb and take a look see at the accelerator pump to see if it is blown. Find a suitable pointer and get some timing tape.

    Now if I can just wrangle a day that is above 40* F where I am off ............

    That said the dash is coming along nicely.........

    Cheers,

    Doc
     
  17. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    8,472
    Location:
    Everett, WA
    No, I just have the DS II, and the work I did last year corrected performance issues I was having during cold operation, but I also have a bone stock engine. SEFI is planned, but definitely in the future.
     
  18. pmrphil

    pmrphil In Overdrive GOLD MEMBER

    Messages:
    828
    Corrosion in the MSD distributors is very common, it looks like someone installed the "blue" springs in yours. There is also a replaceable bushing under the weight plate to adjust how much mechanical advance you want, it varies according to the bushing diameter. 16-18 is about as much initial as regular engines can handle without hurting start-up reliability. I'd check the vacuum advance unit also to see if it's operating properly.
     
  19. PonyExpressRider

    PonyExpressRider In Overdrive

    Messages:
    866
    Location:
    Sutherlin, OR
    I missed that it was a 77.... :( I didn't see the year, that's why I added the qualifier (If applicable).

    just reading it sounded like everything else had been checked and double checked... distrib advance usually gets overlooked.

    Vacuum Advance Module possibly going bad is a good call also!
     
  20. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    8,472
    Location:
    Everett, WA
    Or not under proper control. That's a problem I solved on Babe, so that cold operation timing wouldn't give as much in order for the engine to warm up faster, and using the proper vac source depending on engine temp.
     

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