Results 1 to 7 of 7

Thread: Mysteriously poor running engine after jump starting

  1. #1
    Join Date
    Jul 2016
    Location
    Austin Texas
    Posts
    192

    Mysteriously poor running engine after jump starting

    So I guess it's the season for stressed batteries (been seeing a few threads here lately). I'm having a strange problem with how my car runs sometimes immediately after a jumpstart.

    I'm been making some audio-related tweaks to the car, and the process sometimes drains the battery (lights on, amp on, radio on etc while car is off) while I've been working. That's pretty much just my doing. It might not be the greatest for the battery, but the battery is cheap and on the older side, so I'm planning on replacing it with a better one soon anyways.

    My issue is when I jumpstart the car, I sometimes have issues. I use a 300A jump box connected to the terminals under the hood, and pretty much only use it fully charged. I've used this jumper for a while and it's never given me any issues, usually jump starting the car easily.

    Here's what's been happening: when I crank the engine, it turns over somewhat reluctantly, but still definitely fast enough to start it. It might take 5 seconds or so of cranking, which is unusual. Okay. But when it does finally start, the engine runs EXTREMELY poorly, like it has multiple misfires. The traction light also comes on, and all the electronics dim horribly with the engine as it labors tremendously to turn over. Removing the jumpbox at this point makes it even worse.

    I always turn it off almost immediately, recharge the jumpbox and try to start it again later. It might repeat the same behavior, or the engine will instead turn over easily, and it will start and run fine, with no warning lights.

    My first inclination would be the alternator. But the alternator is an new Bosch installed only a few months back and it seems to have no problems. I've already replaced the grounding straps too. Again the battery isn't terribly new, but my mechanic maintains that it will have no bearing on how the car runs once it's started.

    Any ideas? EDIT: I remember someone else mentioning something like this happening, but can't find the thread.
    Last edited by usinjin; 07-07-2020 at 12:20 AM. Reason: Another detail added
    2005 Jet Black ZHP Sedan "Adriana" || TunedByDaniel || BMW Alarm + Fuel Lock || ORION V4s || Eagle Eyes || 435i Coupe Sport Seats || Perforated Leather X5 M-Sport Wheel || FLOW Designs Lip

  2. #2
    Join Date
    Feb 2013
    Location
    Austin TX
    Posts
    6,069
    Did you look for codes after the issue showed ? Sadly, I don't have other ideas.
    2005 IR / black / 6MT
    150,000 miles

  3. #3
    Join Date
    Jul 2016
    Location
    Austin Texas
    Posts
    192
    Quote Originally Posted by fredo View Post
    Did you look for codes after the issue showed ? Sadly, I don't have other ideas.
    Guess I could've checked when I went to the Advance earlier but forgot. I'm going to assume it was electrical related. Bought the biggest battery they had that would fit, which was a Duralast AGM H8 900 CCA. High internal resistance draining the current away from the rest of the car on a cold start? Who knows. At any rate, battery was indeed shot, and my starter has never sounded happier.
    2005 Jet Black ZHP Sedan "Adriana" || TunedByDaniel || BMW Alarm + Fuel Lock || ORION V4s || Eagle Eyes || 435i Coupe Sport Seats || Perforated Leather X5 M-Sport Wheel || FLOW Designs Lip

  4. #4
    Join Date
    Jan 1970
    Location
    Southern California
    Posts
    17,437
    E46s do weird things on weak batteries, including poor running. I don't know of any other car that's like that. So in theory, your mechanic is right. But not with these cars.

    Sent from my SM-G988U using Tapatalk
    Randeaux/Rando/John/jr - '06 Cic ZHP; Southern California
    "ZHP or not, I still like you"


    ZHP Performance Package, Cold Weather Package, Leather, Jet Black/Black/BlackCube, NAV
    ESS Stage 1 Twin Screw Supercharger, Sprint Booster, BMW Perf Intake, Magnaflow Exhaust, Dinan TB & STEP S/W, Ground Control Coilovers, UCC Sway Bars, Apex EC-7 18x8.5 ET38
    Dynavin D99+, Hardwire V1 (w/V1 Connection), BSW Stage 1 Speakers, Kicker Amp/Subwoofer
    BMW Performance Strut Brace, Orion V2 Angel Eyes, No-holes License Plate, SMG Paddle Shift Mod, Besian VANOS, Gold DISA, Fan Delete, M3 Side Mirrors
    Note: Actual car no longer resembles signature picture

  5. #5
    Join Date
    Sep 2018
    Location
    Austin, Tx
    Posts
    156
    These are classic symptoms of low voltage. When the engine is reluctant to start there is most likely a large voltage drop from a poor jump box connection. This causes control modules to act up, sometimes a misfire occurs and the DME turns the cylinder off until there is a key cycle.

    I personally would not worry about it while you are discharging the battery like you are. Finish your wiring, replace the battery and clear the entire vehicles fault memory. If it still continues to happen start diagnosing at that point.
    Current Garage... '00 R11S, '09 HP2S, '12 R12GSA, '00 Gray 332iT, '00 Black 323iT (wife's), '02 Alpine 325iT (Eileen, Track Wagon), '02 Japan Rot 325iT, '04 IR ZHP Sedan

    Instagram @ HillPerformanceBimmers
    Email to George@HillPerformance.com

  6. #6
    Join Date
    Jul 2016
    Location
    Austin Texas
    Posts
    192
    Thanks all for the replies!

    Quote Originally Posted by GeorgeH View Post
    These are classic symptoms of low voltage. When the engine is reluctant to start there is most likely a large voltage drop from a poor jump box connection. This causes control modules to act up, sometimes a misfire occurs and the DME turns the cylinder off until there is a key cycle.

    I personally would not worry about it while you are discharging the battery like you are. Finish your wiring, replace the battery and clear the entire vehicles fault memory. If it still continues to happen start diagnosing at that point.
    Agreed, I think that must be it. It seems strange that once the car was started and the alternator is spinning, there could still be a voltage starvation. I know that the battery likely had a high internal resistance due to age, which would greatly diminish the ability to drive the electrical load of starting it, but once it was started, I'm not too sure about how that would play out.
    2005 Jet Black ZHP Sedan "Adriana" || TunedByDaniel || BMW Alarm + Fuel Lock || ORION V4s || Eagle Eyes || 435i Coupe Sport Seats || Perforated Leather X5 M-Sport Wheel || FLOW Designs Lip

  7. #7
    Join Date
    Sep 2018
    Location
    Austin, Tx
    Posts
    156
    Quote Originally Posted by usinjin View Post
    Thanks all for the replies!



    Agreed, I think that must be it. It seems strange that once the car was started and the alternator is spinning, there could still be a voltage starvation. I know that the battery likely had a high internal resistance due to age, which would greatly diminish the ability to drive the electrical load of starting it, but once it was started, I'm not too sure about how that would play out.
    There likely isn't but that modules have already seen the low voltage and put themselves into a "failsafe" state. They wouldn't return to normal operation until a key cycle.
    Current Garage... '00 R11S, '09 HP2S, '12 R12GSA, '00 Gray 332iT, '00 Black 323iT (wife's), '02 Alpine 325iT (Eileen, Track Wagon), '02 Japan Rot 325iT, '04 IR ZHP Sedan

    Instagram @ HillPerformanceBimmers
    Email to George@HillPerformance.com

Similar Threads

  1. Dinan e46 engine software and intake. Anyone running it?
    By Xcessive46 in forum General -- ZHP Related
    Replies: 12
    Last Post: 02-03-2018, 07:15 PM
  2. Engine rattle, SES light and rough running...
    By Zaks in forum Mechanical | Troubleshooting
    Replies: 3
    Last Post: 11-15-2017, 07:42 PM
  3. WTB: non running ZHP in need of an Engine/Trans
    By gfortner in forum ZHP-Related Parts & Accessories (no vehicle sales)
    Replies: 0
    Last Post: 05-13-2015, 07:16 AM
  4. Poor Engine Performance
    By NorCal-Dimitri in forum Mechanical | Troubleshooting
    Replies: 63
    Last Post: 02-03-2015, 11:37 PM
  5. Poor running
    By prowlerflyer in forum Mechanical | Troubleshooting
    Replies: 11
    Last Post: 11-23-2014, 07:26 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •