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Issues Holding Idle & Starting

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Old 09-13-17, 10:54 PM
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Issues Holding Idle & Starting

So my car is having issues idling ( what a shock on the forums )

basically it starts every time i crank it but its like theirs a misfire and it wont hold idle. TPS is fresh and adjusted but still does the same thing

i was pulling the car into the garage one day and it stalled and then backfired. started right back up. but did the same thing. ever since then it has gotten better idle wise, ( dosent backfire as much anymore ) by replacing TPS and putting Plus Gas and new two stroke oil after draining the gas tank.

while taking apart the top end to see if my injectors maybe needed a cleaning/rebuild. i noticed the gasket between the throttle body and intake manifold wasnt there? so could that be apart of the issue? Vacuum leak? while im under the intake manifold im replacing the vacuum lines in hopes that the issue will go away but i'd like some opinions on what it is i should do to fix this issue.

No. i havent compression tested it bc im scared to do it lmao.

just throw some suggestions worst case scenario if i do fix everything i possibly can and it does the same thing ill compression test it and if its blown. well off it goes to a new owner

here are some videos for a basic understanding of what its doing,



5 Months Ago When The Problem Initially Started.

https://www.youtube.com/watch?v=8RPq4wy3K6U

Starting it with old TPS.

https://www.youtube.com/watch?v=93Xtq1_hw-w

Starting it with new TPS.

https://www.youtube.com/watch?v=feT-KRHnmmE

( yes i know i held it for long but that was to make sure i was getting gas after putting new fuel in )

any help will be appreciated. i will post an update after replacing top end gaskets and new vacuum lines. as well as deleting the secondary throttle plates.

Thanks!
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Old 09-14-17, 03:56 PM
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anyone?
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Old 09-15-17, 12:26 AM
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Did you check your plugs? Are you breaking up in higher rpms?
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Old 09-15-17, 12:31 AM
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That gasket is absolutely essential in any case.
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Old 09-15-17, 11:53 AM
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There is no gasket between the dynamic chamber and throttle body. Just a phenolic spacer. Stalled and then backfired makes me think... too much fuel to air. Did you notice a fuel smell or smoke from the exhaust on restart during this?

In any case... compression test, spark test, smoke test the intake, and fuel pressure test to solve your problem. Try testing the fuel pressure regulator...

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Old 09-16-17, 01:05 PM
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Are you able to pull codes? I've watched the videos and I don't think you're timed properly. Take a photo of the CAS with blindcap off at TDC. The more I listen to this the more it seems like you're not timed. Pulling codes would be smart. Sounds a bit like MAF issues... code 8. But check your timing. Your pulses sound good in the last video ... you're compression is probably good. Take that photo and post it.

Note: It really sucks that you messed with the TPS. You might've opened up pandora's box man hahaha. Oh **** that my friend, will suck big time. At least that will only cause an idle issue in most cases.

Edit: Don't take out the butterflies until you get this sorted out... you're just adding variables and you might go bald over it.

Last edited by Rotary Alkymist; 09-16-17 at 01:13 PM. Reason: Notes
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Old 09-16-17, 09:19 PM
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Originally Posted by Rotary Alkymist View Post
Are you able to pull codes? I've watched the videos and I don't think you're timed properly. Take a photo of the CAS with blindcap off at TDC. The more I listen to this the more it seems like you're not timed. Pulling codes would be smart. Sounds a bit like MAF issues... code 8. But check your timing. Your pulses sound good in the last video ... you're compression is probably good. Take that photo and post it.

Note: It really sucks that you messed with the TPS. You might've opened up pandora's box man hahaha. Oh **** that my friend, will suck big time. At least that will only cause an idle issue in most cases.

Edit: Don't take out the butterflies until you get this sorted out... you're just adding variables and you might go bald over it.
I'm not sure how timing could be off if this issue began while driving (physical adjustment anyway). I also don't think it would start so easily if ignition timing was that far off, but spark is one of the ABCs of internal combustion so I would hook a timing light up and check for spark and proper timing to rule it out before anything else, pretty simple test before spending any other time or money.

TPS can cause all sorts of goofy things with drivability and idle, especially series 5.

Last edited by NCross; 09-16-17 at 09:22 PM.
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Old 09-17-17, 11:27 AM
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The CAS could've been loose and we're just taking his word for it. Check the CAS. It takes 5 minutes. I always start easy and cheap. Then move on to hard and expensive if you have to.
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Old 09-29-17, 08:18 PM
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i had an issue with mine where my uim wasnt sitting flush with the lim. it was "misfiring" and not holding idle like yours. maybe that is something to look into. give us updates as well!
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