Car Still Wont Idle (BC 272 Cams?)

[WesternMD_VR4]

I posted a few Months back after getting some work done from Atlantic Motor Sports. I replaced the TB as thought could be problem but wasnt. maybe the ECU but I had cams installed a few months back and they have no idled right since...it has to be something with the cams what all could cause this? i saw somewhere online about maybe a CAS wire? any idea they are BC 272 car drives fine just wont idle...

 

[slowpoke]

How does it idle? Surge? Dies? Idles high? Could be different things depending on what your idle is doing. More info would help. Just trying to help.

 

[WesternMD_VR4]

cold start it will stall if I dont have the pedal pressed. once running and temperature goes up it wont stall. it goes from like 700rpms then up to 1500 then back down and it makes it hard to get going in 1st gear sometimes... people at Atlantic Motor Sports said 2 cylinders under 1k RPM's were randomly shutting off?

 

[CutlassJim]

People at Atlantic Motor Sports need their dicks kicked in. Sound like a FIAV/ISC problem and vacuum leak. Are the coolant lines still hooked up to the throttle body? If not hook them back up. Do you have any way to log ISC position and TPS? You want to make sure your base idle is correct (5°). That your throttle closed switch is being made. That you have no boost leaks. Test the coils on your ISC. And that your BISS is adjusted so that when fully warm at idle it's sitting at 30-40. In that order. If you have done that stuff go do it now. I can already tell that your ISC is bottomed out if it's idle surging.

 

[slowpoke]

Agreed 100% dealt with idle issues for years. Take the time and those steps. Dont cut corners.

 

[EfiniX]

Quoting WesternMD_VR4:
cold start it will stall if I dont have the pedal pressed. once running and temperature goes up it wont stall. it goes from like 700rpms then up to 1500 then back down and it makes it hard to get going in 1st gear sometimes... people at Atlantic Motor Sports said 2 cylinders under 1k RPM's were randomly shutting off?



+1

 

[WesternMD_VR4]

hmm I can check all those things...it idled fine until the cams were installed..hard to think it be a vacuum leak when the second cams were put in it started doing this...AMS said it was the TB..so I bought a new one and replaced it (400$ later in labor and parts still isnt fixed) so now there telling me its the ECU..there 99% its the ECU..im not talking down on AMS they do good work but they dont know what the problem is and I know they want me to remove ECU and take it to ECMLINK and have them fix it but i know ill spend all this money and that wont even be the problem...it has to do with the Cams I know it

 

[tektic]

Unless your cam angle sensor is off a fast idle has nothing to do with cams. Without checking all the aformentioned points of intrest you didn't do proper diagnoses. You can cut that list down with a fast idle air valv block off plate. But if you have a new tb like you say your fiav should be functional. Now you just need to set the isc properly. There are hundreds of people with this issue. None have solved it by changing cams.

 

[strokin4dr]

There has to be someone local to you that can set the damn idle for you for a 6 pack.

I highly recommend getting ecmlink for any 4g63 car. It is invaluable for how easy it is to use (once reading up on how it works). Makes getting everything in line a breeze.
This should be a 1 hr process tops if everything else is set up properly.

It's funny listening to some of the dsms at local meets. The owners "do all their own tuning" yet the cars won't idle on their own or surge like hell, lol.

 

[WesternMD_VR4]

they did do ecmlink I have v3 and thats what they used and it didnt fix it..the second the cams were put in it started this rough idle...im over $3000 dollars in now.it just goes from 700-1500 rpms it goes down to about 700rpms then it goes up to about 1500rpm's...when I drive its fine

 

[brisvr4]

It sounds like they screwed up the mechanical timing when they fitted the cams.

 

[90blacktsi]

Post a thread and a log on the ecmlink forums . If your tuning with the LINK that's the forum you want to be on . Very helpfull over there

 

[CutlassJim]

Quoting WesternMD_VR4:
they did do ecmlink I have v3 and thats what they used and it didnt fix it..the second the cams were put in it started this rough idle...im over $3000 dollars in now.it just goes from 700-1500 rpms it goes down to about 700rpms then it goes up to about 1500rpm's...when I drive its fine



This is the definition of idle surge. I'm not sure what they touched but a boost leak test is mandatory. Too much air is getting by the throttle body!

 

[WesternMD_VR4]

they fixed all the boost leaks at AMS when I went in last time...that didnt fix the problem...Im thinking either the ignition module or the ecu..but it seems so many things can cause this. I dont know why 2 cylinders are not firing though

 

[strokin4dr]

I'd love to see an idle log of this car. Post up.

 

[dsm5062]

Quoting WesternMD_VR4:
I posted a few Months back after getting some work done from Atlantic Motor Sports. I replaced the TB as thought could be problem but wasnt. maybe the ECU but I had cams installed a few months back and they have no idled right since...it has to be something with the cams what all could cause this? i saw somewhere online about maybe a CAS wire? any idea they are BC 272 car drives fine just wont idle...



I would say if they didnt do an idle reset after replacing the throttle body, that may be the issue. The throttle body that was on the car had a fiav block off plate so the idle was set for that originally. I know because I built the car lol as far as randomly dropping two cylinders generally a ignition control module will do that when it is starting to fail.

 

[vr4play]

If you have the capability I would remove the ecu and ck the isc drivers inside. If they are blown then the car will idle surge and not want to start when cold. It could be just a coincidence that it blew after they installed the cams. Removing the ECU is fairly easy. There are only a few panels and bolts to get it out. Then 4 screws to get the cover off. It will be obvious if that is the problem or not. It will look like this.

 

[FilthyEvo]

Doesn't want to start when cold? Have you looked at the Coolant Temp Sensor? Maybe the wires became brittle and broke off from the plug.

I am looking into the same issue, and the Coolant Temp Sensor comes up a lot in my searches.

 

[WesternMD_VR4]

Its starts in cold well I live In Maryland it's been cold lately it was outside for 2 months and it started.Im starting to think that its the ECU overcompensating for the cams(Thanks Dustin) and possibly a faulty ignition module which I have replacement on the way. We are going to reset the idle also Im going to try to do most of this on Saturday at a friends garage. I Will post back I am also removing ECU and dropping it off at ECMLINK I can try to take it apart and maybe post pics of the inside for you. As for the Idle Log asked about earlier I do not have it so I cannot show you sorry. I am trying so hard to get this car on the road right this is only thing in my way I will post more Tomorrow on Updates

 

[WesternMD_VR4]

ok really Only replaced the Ignition Module...Idk if it was all in my head or what but not it surges like 1000rpms to 15000rpms much better than it was..i didnt have time to do the idle reset...or remove the ecu unfortunataely its been so cold lately and I havnt had a garage to do work in (my friends garage who i went to saturday has a GVR4 and a 1g talon in it so there was no room to pull my car in) I appreciate all the help everyone has given and I will keep up to date on whats going on