Why is this happening?

Discussion in 'Street/strip 400/430/455' started by duke350, Oct 2, 2020.

  1. duke350

    duke350 Well-Known Member

    Few issues going on as I bring my car back to life. I recently did aluminum heads and a TA310 cam swap, rebuilt the 2004r to stage 2(Lonnie @ extreme automatics), disc brake conversion, and minor other body work things. Listed below are the issues I’m having and I don’t know why:

    when braking, pedal is soft despite 6 times of bleeding with no residual air shown for two consecutive attempts at bleeding. If I pump it, car stops fine but engine dies. By pump I mean, press once, pedal goes to floor, then release and press again and the car stops but the engine shuts off.

    2400-2600 stall converter installed. I have a 3000 stall converter, should I swap? The thought is the current one is perhaps too tight.

    off idle sputter-Holley 850 DP carb, fuel level about a 1/8 inch above the bottom of the sight windows front and back. Mixture adjustment screws are about 7/8 out from full closed or lean. This setting seems to produce the best idle. Timing is 16 initial, 34 all in by 2200rpm per the power time thread. Car hot starts without issue.

    there are other weird anomalies, but I’ll start with these. Thoughts?
     
    Last edited: Oct 2, 2020
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Duke, there is no such thing as a 2400-2600 stall converter, or 3000, or any number for that matter. There is only where it stalls in your car. Does the converter feel too tight? Does it drag the RPM down a lot when going from Park to Drive at idle? Where did the converter come from? Jim Weise has a nice line of converters for the 2004R. You might want to talk with him.

    Sounds like there is still air in the system, or the MC is bad. Sounds like it is exhausting the brake booster and stalling the engine, sort of acting like a big vacuum leak. Are you using a hold off or combination valve? Did you hold the valve off when bleeding? Maybe try gravity bleeding it for a while and see if you get a steady pedal that way.
     
    Max Damage likes this.
  3. Max Damage

    Max Damage I'm working on it!

    Totally sounds like a Vacuum leak in the Brake booster, assuming there is one... That would explain both the dodgy braking performance and the dying after pumping.
     
    chrisg, GS464 and DasRottweiler like this.
  4. DasRottweiler

    DasRottweiler -BuickAddict-

    Check engine vacuum with a vacuum guage . Adjust your idle mixture screws using guage to find max vacuum. 1 to 2 turns out from in/lean, 7/8 out is alot...
    If it is below 15 , you could possibly benefit from a vacuum cannister and/or pump , providing the booster is working properly. Jim
     
  5. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    Pumping the brakes evacuates the booster and acts like a big vacuum leak. The fact that it's stalling indicates to me your engine is very lean at idle already. Try turning the screws out some and make sure you don't have leaks elsewhere.
     
    Last edited: Oct 2, 2020
  6. duke350

    duke350 Well-Known Member

    Thank you guys for the prompt responses. I’ll troubleshoot more with the carb when I get home. I didn’t have a vacuum gage at the time, but just purchased one for this tuning. I’ll report back the findings on that issue.

    the converters I have are billet 9.5” ones from Lonnie at extreme automatics. The “3000 stall” one is the original unit I bought with the trans when it was built as a stage one set up behind the original 350. When I swapped to the 455 and rebuilt it, I added then, the 284-88h cam with the full rebuild and ended up over torquing the trans. When I swapped these aluminum heads, I shipped the trans out to be freshened up and upgraded to stage 2 so it could handle the increased torque. I ended up buying another torque converter at that time, fearing the previous one (much more loose) was damaged when the trans crapped out. This new TC was stated to have a 2400-2600 stall. I now think it’s too tight for my liking and am contemplating switching back to my other one. This new one drops engine rpm ~275 or so from park to drive. The other one barely dropped rpm at all and would flash to 3k when you floored it. I haven’t beaten on this new set up yet to see the stall speed as the brakes are unreliable and things are still breaking in(trans/engine).

    brakes are from “Pirate Jack” and have an 8” power booster that is new with the kit. How can I check for vacuum leaks on it?
     
  7. duke350

    duke350 Well-Known Member

    the kit also came with a disc/disc combination valve that I installed as well.

    7/8 out on the carb, as in not quite one full 360• turn out from full lean/in is where I’m at. I’ll adjust these again with a vacuum gauge for best results. It seems like I’ve got a few gremlins going on.
     
  8. DasRottweiler

    DasRottweiler -BuickAddict-

    Oh, I misunderstood.
    What kinda carb? Perhaps the jetting is too lean . Is the 310 a borderline cam as far as powerbrakes? Jim
     
  9. Bens99gtp

    Bens99gtp Well-Known Member

    Do you have the correct hole on the brake pedal......if you are using power brakes but have it in the top hole on the pedal your ratio will ve jacked up and alway you to nlow right through brakes from too much input pressure.

    I would try turning the idle screws out some......is this 2 corner idle or 4 corner.....its sounds a little too far in to me.....

    Check the air gap adjustment on the squirter on the front bowl.......you shoukd see the pump arm start to move the instant the main throttle arm moves.....if the pump srm isn't moving its going lean for sure......there is plenty of videos about adjust the accelerator pump on holkeys online
     
  10. duke350

    duke350 Well-Known Member

    holley 850 double pumper is my carb. TA sight says power brakes okay for the 310. I’ll report back my vacuum readings after troubleshooting with the gauge hooked up at idle
     
  11. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    You need 10" of vacuum minimum for power brakes. My engine makes 15" in Park, 12" in gear, and I have no problem with my brakes at all. The same converter will react differently depending on engine torque car weight, and gearing among other things. That's why I said there is no such thing as a ____ stall converter (fill in the blank). The same converter will stall higher behind a big block than it did behind a small block. It will stall higher in a heavier car. It will stall higher still with taller gearing. Lots of variables. If you think it's too tight, it probably is. If you had any kind of transmission failure, have the converter gone through and flushed out.
     
    Oldskewl59 likes this.
  12. Schurkey

    Schurkey Silver Level contributor

    I have no idea how a 200 4-R can hold up behind a big-block in a moderately heavy car.

    Air still trapped in the system, or
    Faulty master cylinder--front or rear hydraulic circuit failed
    Low-drag calipers without a Quick Take-Up master cylinder, or
    Rear brakes WAY out of adjustment.

    If the master cylinder is tipped "up" in front like most are, there could be a considerable amount of air trapped in the master that will NEVER bleed out until you raise the back of the car, or unbolt the master from the booster WITHOUT REMOVING THE BRAKE TUBES so the master gets tipped "down" in front. Then tickle the brake pedal or press the primary piston with a wood dowel or Phillips screwdriver to release the air into the reservoir.

    I don't know about "sight windows".

    7/8 turn on the idle mixture screws seems VERY lean to me. Are the venturis dripping gasoline at idle? What is the idle speed in Neutral? In "Drive"?

    First Guess: Advance curve is way too quick. 34 total at 2800--3000 would be better. What about the vacuum advance?
     
  13. duke350

    duke350 Well-Known Member

    No vacuum advance hooked up. But something else is wrong. I went to start the car today and there was a misfire that I couldn’t isolate. It ran very rough. Finally after checking everything, I noticed the HEI cap was worn irregular at the carbon brush area. Replaced cap and rotor with a spare I had but it still doesn’t seem right. I can get it to idle, best of 8-9” of vacuum, sometimes 10-11 but only for a brief second. Sporadic pops and black smoke out the passenger side exhaust pipe. Something is off. I removed both valve covers and took video of the rocker geometry and it seems normal. But Something isn’t right. Too much timing maybe? Just a WAG, which doesn’t even make sense to me. Best idle came from 1 1/8th turns out from lean on the four corner idle. I was way off there originally.
     
  14. duke350

    duke350 Well-Known Member

    My fear is something catastrophic like a whipped cam lobe or something. I had two lifters break post rocker arm swap a while back. Details of that event are in the “head swap questions” thread I wrote as I worked through that issue. But the car had been running and idling well since until today. Oil is fresh 10-30 with a Lucas oil zinc additive to not have this issue and I broke the cam in properly prior to this oil change. Just has me stumped.
     
  15. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Have a look at the spark plugs Duke.
     
  16. Bens99gtp

    Bens99gtp Well-Known Member

    Are wires crossed????? 5 and 7 are a common oops
     
  17. duke350

    duke350 Well-Known Member

    dangit wizard! How’d you know they were heavily laden with soot?! I’m going to file them with sand paper and clean them all. I’ll recheck gap. Right now the posts are perpendicular to the electrode in the center which is what I thought was right. Obviously I’m in the ASE infancy stages with mechanic work. Learning with each failure!
     
  18. duke350

    duke350 Well-Known Member

    21E44BEC-A8BA-4426-B672-4A3DBF4DEA45.jpeg FE9B685B-F1C2-4778-B53C-C5F1E1F80EB1.jpeg # 4 plug. They have all looked the same so far. Cleaning with brake cleaner and light scrub with 120 sand paper.
     
  19. duke350

    duke350 Well-Known Member

  20. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

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