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  • #31
    Alright, finally car is on ground. Took car out of garage and for very short, like 1000 ft run, brake pedal has no vacuum boost. Was fine with carb, but not with EFI now. Was working to set higher idle, was set to 900, would idle 950 to 1050, then set out to increment my way up to 1300, to get vacuum increased, see if I could get my power brakes back without having to move to extra hardware. Well, about 20 minutes into the effort, all is fine, then control system goes wonky, IAC is hunting, AFR is jumping around, idle starts dropping to 500, can control it with throttle, then stalls. Can't get it to restart. Fires, and seems like it wants to, but won't stay running. Reset learning, re-loaded engine baseline tune, let it cool 30 minutes, still no start, will try, but won't idle and stalls, then floods. Let it sit overnight, disconnected PCV vacuum and plugged port to throttle body, was able to get it started, but, would not idle, stumbled, could not use throttle to adjust it one way or another, stalled, no start again, flooded. Checked all connections, everything is secured, tight, still good. Fuel pressure is 59 to 60 psi, 1/2 tank fuel. Distributor did not change, it is fully locked down and has been since install and initial 12 deg set point. When it attempts to run, do not hear any misses, and no backfire, so timing seems still good enough. Have not tried to start taking it apart to see what might be wrong yet. If I have to go there, will start with taking plugs out, setting engine position to number 1, @ 12 deg mark, check distributor alignment, take distributor out to check the gear. Don't want to go there yet if there is something else I can check or do? Any suggestions? Engine has been running fine up until now since May 31 post. Baffled as to what went wrong?

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    • #32
      BTW, the engine was idling fine at 1300 for about 4 or 5 minutes before it went wonky. Note I could not use the throttle to control it, not as i stated above. Just trying to give small throttle inputs seems to not help. Adjusted idle adjuster back off a bit just to see what would happen, still no change.

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      • #33
        TPS?
        Air Temp Sensor plugged in?
        Is the brake booster leaking?......higher idle means air leak.
        At 43,861 MPH Elon Musk now owns the fastest car in this Galaxy

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        • #34
          I was able to reset the TPS set point after setting new idle limit. All was fine for at least 5 minutes or so. Air temp sensor is plugged in and did not change location. Checked brake booster prior to doing the idle adjustment test, and it was fine, no leaks. My my vacuum was about -6 to maybe -7 max, mostly in -5 to -6 range at 900 idle, which is way too low for power brakes. With 1300 idle getting -8, still too low, but then the engine quit running so now that is moot point. Will disconnect the booster and plug that port on throttle body, then report back.

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          • #35
            " Reset self -learn "

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            • #36
              Did that yesterday after it stopped and after I reset the loaded tune. Also looking at possibly the charging circuit not being able to charge the battery at idle between cooling fan runs. The battery voltage is below 12 near 11, and dropping to just under 11 now, when cycling key to ignition on. Wondering if this is contributing to the issue at start. After adjusting the idle to 1300, it was taking longer for the fans to cool the engine to the point where they would shut off, much longer. Just a hunch. Also, when i activate the ECU and the fuel pump runs, engine not running, should I see the fuel pressure reach the regulator set pressure of 58 to 60 psi? I am not seeing that if so, gets to about 29 psi from the edelbrock guage display during the pump run before it stops.

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              • #37
                I reset the learning, again, and reset modifiers, battery is fully charged, so that's not an issue, left the charge system connected with a 40 amp boost to be sure no voltage issues. Still not able to start. Acts like it wants to, but will not. Floods. Try adjusting idle adjuster and still not able to change the result. Air temp sensor is working fine, 77 deg. IAC says its 50% prior to start, fuel pressure is like 29% by the time the tablet connects and the fuel pump is turned off after turning the ignition key on. I am assuming the ECU is turning the fuel pump off due to meeting required pressure, but seems like it should be reading 58% where I set the regulator. Is this true or false? I have no other means to measure the fuel pressure except using the edelbrock tuner application. Trying to figure out what failed at this point will be painful. I can take the plugs out, then set the engine to firing position, check the distributor. Then if that looks ok, then pull the distributor to see if something went wrong with the gear. I did change the gear to a howard cams carbon fiber gear rather than sticking with the bronze gears I have been using as they wear out frequently. I can see if that is the issue. Looking for where to go next?

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                • #38
                  PF3 does not monitor fuel pressure.
                  Tablet display -= is for visual reference.

                  Anything aftermarket ? Trans controller ? throttle body bracket for kickdown cable/accel pedal? etc?

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                  • #39
                    Actually the PF3 does have fuel pressure sensor and reads that pressure on the tuner app. It is how I set my fuel pressure regulator from 43 psi to 59 psi. It went up in small increments as I adjusted the regulator. Page 5 of the installation has a picture of the manifold. The fuel pressure sensor is on the input of the fuel rail passenger side of the manifold.

                    My car has a 6 speed manual, so no kickdown or other accel gadgets. Like i said in the post when this issue started, everything has been running fine on a daily basis since the end of May. In fact it started and ran fine the day before it died, and for a very short drive. The engine was idling for about maybe 20 to 30 minutes before it died, no issues up until it started having problems. I now have both the front and the back vacuum ports to the throttle body plugged, no PCVs and no brake booster connected. Everything in the fuel system is new, new tanks inc tank with in tank fuel pump, new holley ultra pro hose and fittings, new holley billet fuel regulator, new holley billet fuel filter, fresh gas.

                    Anyhow at this point sure would be nice to be able to log data to look at while its starting up to see what the control system is attempting to do and what the other inputs were reading.

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                    • #40
                      I realize that support seems to come from this forum exclusively, and that is very useful when looking for solutions to isolated issues. But, when something goes bad all the sudden and it is not something easy to figure out, like my problem detailed above, sure would be nice to have some trouble shooting guidance, like a "how to trouble shoot significant problems" document. I know, yeah, one can go back through the entire setup, and check the distributor alignment, timing alignment, all electrical connections, and see if each sensor has a legitimate input value on the Etuner app, but, that only goes so far. If a sensor is not operating properly, all the sudden, how does one figure that out, if it appears when the system is turned on it is operating? Being a controls software engineer for a very large aircraft jet engine company, my background will help in finding and hopefully isolating the problem I have, maybe. For the work I do however, we have data collection that really helps diagnosing issues. With out a data logging capability, that really limits what one can do debugging wise with ECUs. So I have come up with my own plan to isolate subsystems as operating or not, or setup or not. And if say fuel and ignition look good, that leaves other sensors and the ECU itself. So for each sensor, guess I will have to go on the internet and search for testing methods, and possibly pickup all the necessary test equipment to do the tests. But wait, I have a fancy ECU but it can't help with that, cause it can't log data. So, investing more money on top of the significant level of investment already, not to mention the amount of time too, to find a problem that out of nowhere shutdown a completely working system. Yeah difficult to accept. Hopefully these comments don't offend the moderators, it's just the simple truth. You all do a great job, but, some customers, when significant issues occur, need a little more direct help.

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                      • #41
                        Question ?

                        Since your issues started, have you " Reloaded Firmware & reloaded the MAP ?

                        if not, please try it. 1st -- clear self learn 2nd. reset modifiers 3rd. reload firmware 4th. reload your specific MAP........Dont Run the Setup WIzard.

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                        • #42
                          Did 1, 2 and 4 multiple times prior, but, did all of these, one more time, in the following order: reloaded firmware, cleared learning, reset modifiers, reloaded map 32225. Still no start. So took plugs out and set timing to 12 deg mark, distributor setting is still dead on where I indexed it, no slop in distributor gear, all is good. Plugs are no where near normal, fouled a bit, not real bad, but not good either. This fouling could be due to the period of time where it was killing itself slowly into stalled state. The plugs are R25 with gap set at .045. I was running an HEI with high output MSD coil before switching to the EFI. I am running an MSD 6AL CD box, old version, but not many hours on it. I am also using a Summit solid state coil 850615, https://www.summitracing.com/parts/sum-850615, purchased new for this conversion. The alignment of my low tooth is spot on in the distributor as well. Pictures attached showing timing mark 0 at 12 deg advanced, distributor low tooth alignment, distributor number 1 cyl alignment and spark plugs right side is 1 to 7, left is 2 to 8, bottom right is 1.

                          I will be checking fuel pressure next at the regulator once my analog gauge comes in so I can attach it to the regulator pressure output port.
                          Attached Files

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                          • #43
                            Have you tried to remove CDI box & run coil direct? Use Blaster 2 coil ---primary resistance .7 ohm.....Dont use a high current coil or may injure the ECU.
                            Just for testing isolate the 6A box...

                            Then check operation ----Orange coil wire to + white wire to -.
                            Last edited by 2700 Cast; 06-18-2020, 08:22 AM.

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                            • #44
                              Update after getting back to this after being out of state for a week. I installed new plugs, fresh fuel, added an analog fuel pressure gauge to the regulator pressure port, and checked the MSD box plus coil. MSD box and coil are fine. Fuel pressure on gauge is 58psi before pump is shut off after ignition is turned on. Gave it a go and it started right up. So fouled plugs and maybe the gas went a little funky after 2 to 3 weeks from when it was purchased. Good that it appears, at least, that it is not due to some other difficult to find component failure. Did two idle runs, second one trying to setup idle to 1200 rpm in attempt to get vaccum higher for brakes. Pulled couple plugs after 2nd idle run, seems like it is running rich still. I saw another post on running rich issue where the response was the vacuum reference needs to be made to the regulator. Thought that was needed just for boosted applications, but have not done that, so will to eliminate that. I will also seal up the passenger side exhaust header collector and pipe where the O2 sensor is as I suspect that is not sealed completely yet. Not sure that will contribute to rich condition.

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                              • #45
                                "With a return system, the base pressure is set with the engine off, but the pump running. For a GM, this pressure is usually set to 58psi (factory fuel pressure in the rail). The vacuum/boost referenced regulator will help to change the pressure in the rail based on the pressure in the manifold. When an engine is idling, it may be pulling 20 inHg of vacuum, which translates to roughly 10psi. The reference to the regulator will allow it to adjust and lower the pressure in the rail to 48psi, resulting in 58psi effective pressure, which is the same as the base pressure."

                                Link: http://injectordynamics.com/articles...ughly%2010psi.
                                At 43,861 MPH Elon Musk now owns the fastest car in this Galaxy

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