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Post by beatrod on May 3, 2020 11:15:41 GMT -5
Ok so start the car idles up a bit about 1400 and starts at about 14.7 but quickly drops to about 11.5 or so. Seems to go into closed loop and never goes to 14.7 again or idle down to about 1000 where I have it set. But if I turn key off and back on quickly it seems to go back to open loop and idles and drives exactly like i would expect. However my problem is that when/if I get on it real hard say 2nd-4th, go down the road a few blocks and then pull in somewhere the idle drops to like 650 and even dies sometimes.. I can drive it normal for 30-40 minutes and its great, but then after a good pull it acts nonsensical. But if i turn key off and quickly back on like to get it back to open loop, it instantly acts right. Enough gas, 255 pump, kirban.. It has plenty of what it needs.. I don't understand. If it was closed vs open loop, why would it act three different ways? Help would be great!
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Post by Stinger on May 3, 2020 12:17:22 GMT -5
Sounds like you've got more than one issue and they aren't related. How it runs after a hard pull is completely independent from open loop/closed loop operation.
Is this "starts at 1400 and 14.7 and quickly drops to 11.5 or so" on a cold/cool start or a hot start?
What's a code scan say?
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Post by beatrod on May 5, 2020 13:28:32 GMT -5
Cold start. Warm start goes straight to 14.3-14.9. Its not throwing any codes.
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Post by Stinger on May 5, 2020 14:36:46 GMT -5
No codes or no check engine light?
It won't be closed loop on a cold start. Has to get mostly warmed up before it will enter closed loop operation.
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Post by beatrod on Sept 8, 2023 4:30:41 GMT -5
Got this mostly figured out.. Doesnt die after pull anymore. But still idles high unless i cut power and give it back quickly. Also doesnt go lean on decel in gear. Also, the super rich at start doesnt really do it anymore. So high idle, doesnt go lean on decel. Reset idle, tps, timing, cleaned iac, new plugs/wires didnt help while back.. Still have no clue lol almost like it has something to do with the "start" program in the ecu.. But i highly doubt it as its a factory ecu (la3)...
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Post by Stinger on Sept 8, 2023 13:38:04 GMT -5
It SHOULD go lean on decel, that's programmed into the ECU (fuel cut on decel above "x" RPM).
High idle that is "fixed" with a key cycle is typically a malfunctioning IAC solenoid (dirty/sticking in most cases).
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Post by beatrod on Sept 8, 2023 20:04:23 GMT -5
Right, its not going lean though. Barely even has any engine brake going on... And i suspected as much, thats why i cleaned it but that didnt help any. So i guess il just try putting a new one on. But it still has me stumped on why its not going lean... If its cutting fuel it should go lean even if the iac is staying open.. More so really.. Or perhaps its not putting enough vacuum on the fuel pressure regulator to drag down the pressure.. Idk. First thing first, make the idle act right. Thanks stinger. Hey while im here though... I was wondering if the 3.0 cam syncronizer would fit the 2.3's? It looks the same in pictures but im not holding one to compare.
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Post by Stinger on Sept 9, 2023 0:01:10 GMT -5
I don't think it will enter decel fuel cut if it's in open loop mode. If you've got a AFR gauge for the stock o2 sensor it's easy to see if it's in open loop or closed loop fueling mode.
Technically, it doesn't go lean on decel, it gets zero fuel. So the engine isn't even running, it's just relying on the wheels turning and being in gear to keep the engine turning. The IAC isn't factored into it, nor is the FPR involved. Cutting fuel is done by the ECU (stops firing the injectors, same as it does for the rev limiter).
No idea on the cam sync.
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Post by beatrod on Sept 9, 2023 21:28:40 GMT -5
So if its staying right around 14.7 afr sometimes richer all the way to 10.5 at times, during decel, then its probably staying in open loop? Because thats what it does lol i have the factory o2 sensor still in for the computer sake but have a wideband down stream as well. It stays right around where it should be mostly, thats why i was thinking if it wasnt in open loop that maybe it wasnt going lean because the fuel pressure wasnt being drug down. I was thinking it would still give idle amounts of fuel, i didnt know i cut completely.. So that right there tells me its in open loop. So now i wonder why🤔 what kinds of thinks might cause that? May also be why its got funny idle.. Im thinking something to do with that is always running so cool... Computer probavly thinks it still needs to be in warm up mode.. But now i wonder why a flick of the key changes it.. Like i can start it and immediately flick the key and it idles down and runs "nornal".. Maybe the ecu temp sensor is just bad or getting that way. Il investigate and report back.. eventually. Thanks again stinger!
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Post by Stinger on Sept 10, 2023 0:59:50 GMT -5
There is no such thing as dragging fuel pressure down. The fuel pump is either full power or off, nothing in between.
Decel isn't programmed for "some fuel" because lean = bad. No fuel = safe. Lean also causes backfiring and it can't backfire with no fuel.
If it doesn't fully warm up then it will never exit open loop.
Idle issue is likely unrelated to open loop.
It changes after a key cycle because then the ECU is in a completely different mode as you've reset all timers for afterstart, warmup, etc.
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Post by beatrod on Sept 11, 2023 15:51:02 GMT -5
Makes sense. I was thinking the vacuum on the fuel press reg helped with the leaning it out.. Figured lean is bad with boost and making it fight to run (in gear pulling), but didnt think it had the same effect without making it fight to run. Regardless, i had an idea but not totally sure its advisable, want your thoughts.. I figure the coolant from head and oil cooler/warmer is what puts heat in the system to the heater core then to the thermostat to open it (along with the collant still in the head).. But since that line runs right above the header, even if its not all the way to temp (to show the ecu sensor its warm) it would theoretically pass by the header and get heated more.. Added heat in that coolant could be making the thermostat open premature and the engine never actually getting to temp. Right? If that line was restricted, it might slow the process of the thermo opening..?? That way the coolant actually reaches temp. Of course then it would just ait in that line longer and get even hotter.. And the flow would have to still be there to keep it flowing accross that sensor but might actually make the problem worse when it does finally get to the thermostat... So how would you thinks a good way to avoid all that?? Maybe run that line on the other side of the head or under the header maybe?
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Post by Stinger on Sept 11, 2023 21:14:16 GMT -5
That's where the line runs from the factory and it's not an issue. Never fully warming up is typically the result of the wrong thermostat type (there are two types, and two different thermostat housings and the housing and thermostat have to match). Wrong style = never fully sealed so coolant is always flowing.
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Post by beatrod on Sept 12, 2023 12:02:08 GMT -5
Yea i had a slight suspicioun since it didnt look quite right when i changed it awhile back.. But there only seemed to be like you said two types and neither looked quite right. Il look further. Other than that, i believe the only difference in the 2.3 and 3.0 distributor/cam sensor is the length of the shaft. Everything fit right except it wont drop all the way in because the shaft bottoms out on a little step on the id splines. Just in case anyone else asks you lol
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Post by beatrod on Sept 12, 2023 12:58:03 GMT -5
Yea i had a slight suspicion since it didnt look quite right when i changed it awhile back.. But there only seemed to be like you said two types and neither looked quite right. But what iv gathered is they always have the run cold problem.. I was figuring maybe thats part of all the problems. Il look further. Other than that, i believe the only difference in the 2.3 and 3.0 distributor/cam sensor is the length of the shaft. Everything fit right except it wont drop all the way in because the shaft bottoms out on a little step on the id splines. Just in case anyone else asks you lol so either drilling id a bit longer or pulling shaft to shorten is necessary. My shaft has clip so im drilling.
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