Welcome to CPGNation.com! Log in or Sign up to interact with the CPGNation community.

Surging idle hot start EZ-EFI 1.0

Discussion in 'FAST Support Forum' started by gremlinmt, Oct 21, 2018.

  1. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Yes. I was referring to the phasing. You could carefully drill a hole and use the old cap to see this from idle to full advance - with the engine running. Your phasing could be off at idle.
     
  2. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    Truck drove to work and home again, died going into the parking lot at the grocery store, it seems pretty happy except for the zone between 125 and 150. More learning should help. It's snowing to beat all right now, thinking it's a bad idea to pull the dizzy in the snow.

    Last night I was dreaming of computer controlled timing and not having to pull dizzy every time I want to make a change. Is there anything other than the MSD e-Curve or moving all the way to an Sportsman/2.0 system that does this?
     
  3. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    EZ EFI 2.0 does full electronic timing. If you can find one, there is also an add-on MSD 8981 timing computer. The MSD can sometimes be found on eBay, but only does a mechanical curve.
     
    Last edited: Dec 24, 2018
  4. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    Well, after a week of driving, I think I've got too much timing. It wants to die at stop lights and when the wheels get locked up from trying to stop on ice. There are days I hate Montana. Tomorrow is supposed to get to 41 degrees with above freezing temperatures around 11am. I'll back off the dizzy a bit, add some timing to the plate, put in the heavy spring, install plugs, wires, and cap and go from there. Oh yeah, and make sure the cap and rotor aren't hitting too hard and bending the spring.
     
  5. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    If the initial timing is not causing erratic vacuum, and vacuum is staying high and steady at idle in neutral, initial timing is not the cause. Increased initial timing provides more low-end engine torque - as long as the vacuum stays high with no vacuum needle fluctuation. The heavy springs should make the difference. The looser curve you currently have is probably overheating the plugs at speed, and causing some erratic fueling that causes the engine to die on return to idle. Be sure the vacuum booster isn't leaking when you apply the brakes.
     
  6. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    I guess I need a definition of erratic vacuum. An inch or two, or big swings of 7-10"?
     
  7. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Vacuum should remain steady at idle with no needle swings. Small movements of an inch or so of vacuum can also be stopped by adjusting the idle A/F. If still getting occasional larger swings of the needle at idle every few seconds, drop the initial two degrees until those swings stop. You are looking to find the highest initial timing that give the highest steady vacuum reading. Some of the small or larger infrequent occasional swings could be plug misfire and not due to improper adjustment. I expect 18 degrees initial to offer highest steady vacuum and best operation for your engine, but it could be slightly more.

    You should be able to find instructions Online for vacuum gauge use. It can be used to find many problems with an engine.
     
  8. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    Just came back inside from changing plugs, wires, cap, and rotor. Also pulled the distributor and switched to heavy spring. Set the timing at 14 initial with 18 on the plate for 32 all in. Ran the engine up and found all in at 2800!. Either the black spring isn't actually heavier than the silver or the amount of travel with the limiter plate in is keeping the spring from being fully effective.

    In regular driving I, after I parked I'd get a big dip in vac and rpm and then it would sort of stablize and you could feel it moving around bit even if you didn't see much movement on the vac gauge.

    plugs 12292018.jpg
    These are the plugs I pulled when I changed plugs and wires. 3 looks like crap and probably had a pretty regular missfire.

    With new plugs and wires I went about setting idle and timing but I've hit a snag. Idle won't come all the way down even with the IAC closed. I've got the throttle blade screw all the way off and it's still running about 700 rpm. I check connections at the throttle body on all vac lines and didn't find anything. Next I grabbed my line clamp and starting clamping various lines looking for a dip in idle. The only one that made a real difference was the PCV valve. It's got about 5k miles on it. I'll replace it just in case.
     
  9. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    Well, just went back out there and it would barely start, had to open the throttle blades a bit to get iac under control. Was idling at about 40 iac and I brought it back down to 22. Nothing got touched so I'm leaning towards the pcv valve as the only mechanical device effecting vacuum.
     
  10. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Jeez. Why did you back the initial timing off to 14? That is too low. I suggested 18. You could set that plate at 12 degrees advance and leave it alone. The two springs giving the most tension are the ones to use. Put the throttle back where it was. You likely have the rear throttle partially open - or a vacuum cap or hose off.
     
  11. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    Well, I was at 16 at the start of this and I occasionally had the engine try to die when coming to a stop. This was much worse when at 20. I thought I'd go the other way a couple degrees and see what it did. Plus, I know that worst case it'll just be sluggish and it won't hurt anything. I forgot to mention that I made sure I had clearance for the rotor contact. I've also figured out how to pull the plate and pickup out of the distributor without having to pull the reluctor. Not nearly as scary to take it apart now. It still has a slight surge at idle when hot. I'll see if that settles down with some drive time. At 20 it would take a big dip soon after shifting to park.

    I'd believe I had a cap off if I had any unpopulated ports and I'd believe rear plate open if it didn't magically fix itself after restart, plus I watched the plates while I was under the hood playing with the timing. The rear ports are slightly delayed, some slight slack in the linkage. I'm still leaning towards PCV valve.

    Temperature is plunging and wind is in excess of 15mph and getting worse. I guess that's as far as I can get today.
     
    Last edited: Dec 29, 2018
  12. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    Well, did some around town driving today and made three videos:
    Cold Start

    Warm Start

    and Warm Idle when I got home:


    Obviously not better. I've got enough time to put a couple more degrees into timing. Weather took a weird turn, I've got time to pull the dizzy if I start within the next hour. My experiment failed, I'll do exactly what you tell me to do this round. :)

    Sorry for the music, you may want to mute it. Next time I'll remember to turn the darn stereo off. The hot idle has some surging that easy to see on the vac gauge. Is that timing surge or mixture surge?
     
  13. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Your MAP sensor is bad. 80 key on, engine off, indicates this. Your camera is too far back to read the numbers well.
     
    Last edited: Dec 30, 2018
  14. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    80-90 is normal here. I'm at 3500ft. Key on was 88. I'll take a better shot in the morning.

    It's actually a new MAP sensor, my old one was acting strange and I had just moved to a single plane intake so it seemed like a good idea. The rubber gasket had a flap that was covering the intake port. It still amazes me that it worked at all. I only noticed it on a WOT run down a hill on cool evening. The reading went above 105 which should be completely impossible with maybe seeing 92 on a high pressure day. New MAP sensor went in the next week.
     
    Last edited: Dec 30, 2018
  15. fabr

    fabr Member

    Joined:
    Jan 23, 2017
    The old wisdom of making only one change at at time comes to mind here.
     
  16. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    Yeah, I got to aggressive but the window in the weather made me push hard. The wife put me on christmas light duties today. I had time to dial it up to 16btdc where I know runs OK but then the weather closed in. I've got multiple inches of snow on the ground now. Gonna -1 tomorrow night. Think I'll stay home for New Years.
     
  17. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    Big problem. Truck wouldn't start today. It's stupid cold but it should start. FAST unit wasn't seeing rpm on crank, so I started at the MSD box and checked the gray wire. With ignition on connecting and disconnecting the gray wire to yellow tach wire resulted in injector fire. Moved up to the magnetic pickup wires on the msd. Shorting and releasing caused spark after the coil so it's working. Moved up to the distributor. Plugging and unplugging the dizzy output resulted in injector fire. Therefore distributor pickup. I bought a new distributor, Pulled everything apart and moved heavy springs and limiter plate to new distrubutor. Stabbed it back in and it started up super easy. It was pretty advanced so I brought it back to 17 degrees and let it warm up. Everything seemed good. Checked curve, we are all in about 3500rpm which is faster than requested but I don't know how to slow the curve down beyond here. :/

    Anyway, I plugged the vac advance in and everything went to hell. Timing didn't appear to advance on the timing light but it was jerking around if I reved the engine it backfires out of the throttle body. Mopar distributors can only be installed correctly or 180 degrees out of phase. I don't think I installed it backwards. Would it even run backwards?
     
  18. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    If the magnetic pickup is backwards, it will cause problems. Check you didn't install the distributor one tooth off. Double check the plug wires. The engine wouldn't start 180 out.
     
  19. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    You could still have a MAP going bad. Backfiring will kill those mounted in the TBI fairly quickly.
     
  20. gremlinmt

    gremlinmt Member

    Joined:
    Mar 13, 2013
    Update: I found that my 'ported' vacuum had almost 13 inches at idle. Further checking shows throttle blades not going all the way closed. Rear blades have some slack as well. If they were adjusted a little closer, I'd be able close the blades more. Fiddle farted around with that until I didn't have vac there. Looks like I need more spring on the throttle blades. I'll deal with that in the morning. New vac can is super aggressive. It was pulling in 15 degrees of timing at 5 inches of vacuum. Old can only pulled in 10 and pulled in about 13 inches of vacuum. We adjusted the vac can until it started moving around 12 inches or so. I can't adjust the amount it pulls in so I'll have to see if I can find a less aggressive can. Unless you think it'll be ok to pull in that much?

    Looks like summit has one that produces 5 - 7 degrees at 15 inches. With the standard canister, you can adjust how much vac it takes to pull it in, but not how much advance it has. It appears the summit does the opposite. It adjusts how much advance but not when it comes in.

    Mopar distributors don't have the cam gear on the shaft, it's just a flat blade screwdriver looking thing that stabs in. No way to end up off by a tooth or two. It's either on or it's 180 out. It's interesting that it drove just fine without the vac can hooked up. Honestly, hot restart is better without the vac can. I think it's the cause of my surge on hot start. Hopefully throttle return springs will help.

    I set plate advance to 12 degrees all in at 3500. I'm back at 16 base timing because it was safe. Not sure if I'm going to be able to get a slower curve than that without going to an aftermarket distributor. Both heavy springs out of the Mr Gasket kit are installed.

    I understand your concern about MAP sensors, readings are steady and seem to agree with my vac gauge when running. For now I think it survived.
     

Share This Page