When I start up the car in the morning or after work I have the feather the throttle even to get it started. Once it is idling I have to wait about 5 minutes for it to warm up. If I don't do this it will shut off on me when coming to a stop. The other issue I have has been happening since I put the Eco into this car (never happened in previous car) while sitting at idle (even at 0*F outside) it gets hot enough that the fan has to kick in to drop the temp back down. Any ideas would be greatly appreciated.
Subed. Log your fuel trims and see if there is any irregularity when it stalls. Mine does it sometimes when its cold too. When it happens its showing massive fuel trims and I'm not sure why. When its warm and you push the clutch in, do the rpms drop and then bounce back to normal like its correcting itself at the last second?
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is the ecotec motor stock (as in no tuned ECU with modified fuel/air trimming)?
I wonder if you have the original fuel pump still and its faulty....if you let it prime before trying to start the car it should have a consistent fuel flow to idle higher than normal since its cold. But you dont need to 'pump' these fuel systems in order to get it to start...maybe if the delivery isnt adequate due to faulty lines, pump, filter, etc.
The car should be getting to 195 or so and kicking on the fans by 208 or something to that effect. Thats normal. But is it getting much hotter than 210ish? maybe your coolent temp sensor is bad
04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Y3llowCav - Yes, the RPMs do drop and then bounce back
blu04DD - Motor is not stock and the vehicle was professionally tuned. This didn't start until about a month after the car was tuned. Will check fuel pressure to verify that the pump is working properly. The fan is working as described.
The engine had the upgraded head (SS valves, JBP Stage 2 Cams, GM Racing Valve Spring Kit) when it was in the old car but the LE5 Intake Manifold wasn't installed. That is the only thing that has changed from one car to the next.
Ok so we are likely having the same issue. This only started for me after hp tuning as well. Check your fuel trims though. You'll see that it cuts fuel like crazy when it happens. At first I thought it was loading up but its not. Could be something like a tps or a primary O2 sensor?
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What's your idle rpm set at?
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Argh...I'll have to get HPT loaded onto the desktop to see what the tuner set it at. Laptop took a crap and I have no one locally who has the program. I haven't touched it since I got the car back.
Let me know whatever you find out. I can tell you that we raised my idle from 900 too 1100 and that keeps it from stalling 95% of the time but it's obviously just a band aid and I'd like to actually resolve the issue. Seriously though, I'll put money on you having massive fuel trims when it does it.
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do you have any CELs?
if it stalls, your IAC is most likely bad, stuck, slow to respond, etc.
when it gets to op temp, it doesn't matter as much because its up to temp.
if that isn't it, check your IAT, ECT sensors.
so far as the car heating up and needing the fans when it sits still.... uh, all cars do that.
you need airflow across the rad to keep the engine cool.
ambient temperature doesn't matter, it's a few thousand degrees inside the combustion chambers when they fire, and the coolant is 200* when sitting idle.
the engine is water cooled, not air cooled.
DaFlyinSkwirl (Pj) v2.0 wrote:do you have any CELs?
if it stalls, your IAC is most likely bad, stuck, slow to respond, etc.
when it gets to op temp, it doesn't matter as much because its up to temp.
if that isn't it, check your IAT, ECT sensors..
Nope no codes. I do have another IAC I can try; maybe I'll do that today. I pulled it out to make sure it wasn't gunked up but it actually looked really nice and clean. If not I'll try the ECT next. I'm SCed so I'm hoping it isn't Tmap issues; that thing is expensive.
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Update:
Swapped out the IAC with no changes, I drove it for awhile. Then the other day I plugged the gm reflash pcm back in and drove it around all day. Despite it just blowing, no idle problems. Seems like it must be something with hpt. I know not everyone with hpt tuning has this problem and my tune is done by someone who has a lot of successful jbodies under his belt. A while back we did some more live tuning to try and figure it out but ended up raising the idle to 1100 as a bandaid. It helped a lot but like I said before, it isn't the solution.
OP let me know what you find out and I'll keep you updated on anything from my end.
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Has anyone found more information on this? Still looking for a solution and don't know where else to look.
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Just tossing this out there. My 03 would shut off sometimes when i pushed in the clutch while coming to a stop. But that was before i boosted it. My only engine mod was a WAI. It hasnt done it at all after i boosted it. I just wrote it off as a glitch in the orginal stock tune.
Tinkles(KGM) wrote:Just tossing this out there. My 03 would shut off sometimes when i pushed in the clutch while coming to a stop. But that was before i boosted it. My only engine mod was a WAI. It hasnt done it at all after i boosted it. I just wrote it off as a glitch in the orginal stock tune.
Interesting. That's pretty much what happens to me even with the s/c. Is it an LS Sport? It seems like only some PCMs do it so I'm trying to figure out whats common between them. My PCM is from an 05 LS Sport.
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I swear gm has the worst pcm's in the world.
I had the same issue on my old 02 ls sport witha Eco.
I swapped in a motor from a 03 so it had the different injectors. From my reading the stubby injectors have a slightly different injector constant.
When I was running the 03 style injectors on my 02 computer I would get the same sort of issues where when cold or randomly it would stall out.
Wonder if gm had some old pcm's laying about and just used them.
hmm that's really good to know. I'm going with bigger injectors soon so we will see if that changes things at all. I'd totally believe they were using up old stock, especially in 05 when they were probably trying to get rid of ANYTHING J body related.
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Answer...blown head gasket.
Well I guess that wasn't the answer, but a separate problem in its own right.
Oh thank god... No offense. But I was pretty sure because I'm showing no signs of head gasket problems right now. I'm interested in this PCM situation.
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So what o2 sensor do I need to buy to work with the AEM UEGO setup? I never reinstalled one after I got the car running, but I did make sure there was a spot for one when the exhaust was done.
I think you can buy a replacement from them or find one on Amazon/ebay.
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