Hi, changed the cams over a month ago, and since I've had a little bit of a rough idle. At first i thought it was a lope, but it was inconsistant, and started then when it was warm. Time went on and it seemed to starting doing it more, so i changed plugs (AC Delco Platinum's gaped to .060), and it seemed to have little to no effect. When the car hasnt been driven for a couple of hours or so, it will act fine for the first few minutes after startup, then idle really crappy, so bad that it shakes the motor around (and with poly mounts one can feel it really good). Changed the coil cover, coil packs and boots again the other day and it still seems to do it, not getting much better. Some peers say its a vaccum leak, but all of the lines are free of leaks (sprayed TB cleaner on them, no change in idle). My dad seems to think its fuel related, not sure, changed the FPR before all of this (i think it was before anyway). Seems like im running out of options. No one seems to know why, and a search on here lead to a 5 page thread with no answers. Another thing im not sure if related or not to the rough idle is that when the car's warmed up some, when the rpm's are around 2k the vibes are very intensive, so bad it shakes the whole interior, above that is fine, and below that is fine (except when the idle settles of course). Dunno what else it could be any ideas?
one thing that i noticed is that when i gapped my plugs, it was at .050, I have Delco Platinums as well. That is what the guy at advance auto said they were to be gapped at, and my idle is very smooth.
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when I had my cams I know my idle would lope hard and basically jump all around like yours does, I gurantee, well almost its all cam related...
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What cams? My car has been doing this for quite some time. I've changed plugs, boots, coil packs, fuel filter, and fuel pump (unrelated to trying to solve the problem, but still) and it still persists. Granted, I've never tried regapping the plugs... But anyways, this has been a problem for a long time for me, since before I did the cams. I have had a predator diagnostic tool hooked up to the car and it detects the messed up spark. I am probably going to use HP tuners to fix it when I delete my EGR. It's just not at the top of my list right now, since it only really does it at idle.
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could be a cam issue, but more likely a TUNING issue.... i'm not sure of what 2.4 cam specs are stock, but i'd say most times you really need to have someone who knows what they're doing tune your ecu to match the cams. Tuning for boost is pretty easy by comparison to tuning N/A. Check that your timing is correct, recheck the plug gap, maybe try different plugs (copper). Is it throwing any codes?
Some cams just lope, period, no matter how well you tune them... if you could give us the full spec sheet that you should have gotten from your cam grinder, that would help.
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rhodaz24 wrote:one thing that i noticed is that when i gapped my plugs, it was at .050, I have Delco Platinums as well. That is what the guy at advance auto said they were to be gapped at, and my idle is very smooth.
They were gapped to .050 before i changed them, i thought those were the issue, .060 is what everything says they are supposed to be for that year (minus my owner's manual and my Haynes Manual which say .050), as for the spec sheet, the cams are both .375 lift, at 200 Deg duration. I've got an email with the same specs, but my yahoo email seems to be down at the moment. Scarab, i figured it might be something to do with the computer, but the seller claims they have a smooth idle, but obviously dont. I've tried contacting him about it, he claims they shouldnt do that and something else is at fault.
Ender_Wiggin wrote:They were gapped to .050 before i changed them, i thought those were the issue, .060 is what everything says they are supposed to be for that year (minus my owner's manual and my Haynes Manual which say .050)
Chiltons manual says .060 gap
Liquidplamsa wrote:Ender_Wiggin wrote:They were gapped to .050 before i changed them, i thought those were the issue, .060 is what everything says they are supposed to be for that year (minus my owner's manual and my Haynes Manual which say .050)
Chiltons manual says .060 gap
Is that for a 98? my Haynes Manual says 95-97 is .060 i want to think, and 98-02 is gapped to .050, they're gapped to .060 now, and its still idling @!#$ty regardless.
Changed the IAC today, no difference, i hate wasting money for parts that arent bad..
My 98 the gap is supposed to be 0.50.Are you sure the engine is timed properly?When i changed my cam the timing chain was off by 1 tooth and it had a lopey idle.That might be your problem.
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Wouldnt it do it after starting up (the rough idle), it idles fine for the first few minutes when cold, then starts to run like crap. I'm gonna check the timing again tomorrow, but it was dead on when we put the chain on. As for the gap, the only two places i've seen for .050 was my owner's manual, and my Haynes manual. AC Delco themselves show .060 for a 98, as well as Alldata. It ran about the same with both .050 and .060 gaps though.
you ever think you got the cam timing off ?? its very easy to do
[quote=97cavie24ls(JDM&00s/c sedans™)]you ever think you got the cam timing off ?? its very easy to do
Didnt think so, but with everyone saying that it might be, its more of a reason to check. The cams were locked with bolts when i put the chain on though. If they were timed correctly, what other options do you think i might be? My dad is really leaning on fuel, but i have no other issues when driving.
off topic sorta but i have JBP cams and i dont see that much of a lope at all, think id see more if i tuned my ecu which im planning on doing soon?
Most likely the cams.
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Sounds like the IAC table needs to be raised a bit in each RPM range, get yourself an HPtuner. We have the same issue with the 3800's when you go with a pretty high lift cam, some to the point of actually setting missfire codes. The solution is to raise the idle numbers in the IAC table and bump the rest of the table up a little bit as well. Its a really easy to fix problem if you have a way to do it.
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They really arent too high of a lift (.375), not much different than Secret Cams. Was gonna check the timing today, but its just too bloody hot to do so, might be able to this coming weekend, or maybe before work some day (working nights this week). I just cant see how they could be off. HPTuners sounds like a good possibility, but why arent others having idle issues with similar (ie Secret) cams? Both Cams i have are .375@200 BTW.
just turn the idle up some, thats what i did, i was idling at 700 all choppy and now im at 1200 and its fine.
It idles at stock 1k, maybe even a little higher (like 1100ish)
i remember when i change my cams we didn't get it time properly and the car ran but it was lopy and idled funny realized the tensioner was no working properly so the timing was off next time the guides were moving. FInally got it running properly. I think it is the timing. You may want to check that before you get any serious damage
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^ ya what he said.
i been on the seceret cams for 2 years now. (love them).
idles great.
i personally would gap them plugs at .030- .040.
keep us updated.
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why so close on the gap? I'll have to double check the timing it seems, how can the tensioner disengage when it was fully engaged when i put the chain on? Hmm, need to find time to do all this mixed in with work.
sounds like your drawing vacuum check and see if the head is leaking on the intake side (look below the intake manifold) or it could also be tuning issues.
checked for vaccum leaks (sprayed Carb Cleaner where i could so see if idle would change, got nothing). It might be tuning, kinda odd how these cams are said to make idle as good as stock.
