1G troubles idles down when coming to a stop

[jcarmichael]

start out by mentioning everything Ive done in the last month. put new arps and head gasket and timing belt and tensioners on a month ago had a slight boost leak afterwords... then installed a new cx racing rad last wed and while hitting boost way worse just felt like fuel cut or a boost leak. so Friday I started to try my boost leak test wouldn't hold any pressure. then Saturday I changed to a 2g manifold and a 16g exhaust housing for the turbo same o2 housing same 14b turbo now. my car wants to die at every stop light I have to down shift until I am almost stopped and it bounces up from 400 rpms then idles fine. any ideas would be helpful as this is my daily driver and I have my daughter then next two weeks don't wanna stall with her in the car me I could deal with it but with her I would really rather not.

thanks for the help
Josh

 

[miguelmcv]

Check your ISC It might be off.

Test every single coil in the ISC, It should read from 28 to 32 ohms.

 

[jcarmichael]

yea kept looking around after I posted this and im pretty much narrowed down to isc bad boost leak or idk what else it could be... on my link my o2 doesnt oscilate at all just stays at .92 volts moves a bit but not up and down. leaves me to believe its a huge boost leak. but not sure where to go from there... need to find a how to on where the isc is and to measure it I have an electrical back ground so shouldn't be a big issue.

 

[Talondvr]

DSM ISC motor testing & Replacement - YouTube

http://www.dsmtuners.com/forums/newbie-forum/184093-how-test-isc-motor.html

 

[jcarmichael]

thanks I found that video a second ago now I can just go back to my post on here and get to it when I try it out tonight... can I get the isc off of any talon whether its turbo or not. I have no idea if I will be able to find one at the junk yard or not.

thanks again

 

[SmoochDarling]

I believe any 91-94 talon. 90s are different.

 

[jcarmichael]

awesome I will do some more research to be positive. but better chance I am going to find one on a n/a at the junk yard then on the turbo models. pretty much slim pickens around here.

 

[miguelmcv]

Only the 90 came different (will not work).

But, almost any turbo or not turbo will work. as far as it has the same shape.

The 2gs has a brown back cover with 3 screws, and the 1gs are all black with 2 screws, but they all have 2 holes to screw it to the throttle body, so as far it has the same connector and the same 2 holes to screw to the throttle body,,, they all will work.

 

[jcarmichael]

awesome really hoping that is it then any ideas on why I couldn't build any pressure while doing the boost leak test friday? didn't have my motor 30 degrees past tdc but didn't think that would cause it to not hold anything at all seemed like it went in leaked right out. made my own blt

 

[Talondvr]

awesome really hoping that is it then any ideas on why I couldn't build any pressure while doing the boost leak test friday? didn't have my motor 30 degrees past tdc but didn't think that would cause it to not hold anything at all seemed like it went in leaked right out. made my own blt

Try it at tdc. I never have much luck at 30deg. At tdc all the intake valves should be closed. You sure you don't have a huge leak somewhere? Can you hear the air going through the head at all. Double check everything.

 

[jcarmichael]

I need to get new t hose clamps snapped a couple had to use regular hose clamps. but there on tight double checked them all last night when i was putting everything back together. it sounded like it was going in couldn't really hear it seeping out. might try and get a video next time I try it not sure it will help any more then the info I can provide but maybe. and ill set my timing at tdc didn't know if it was absolutely necessary. I did have a crack in my old exhaust side of my turbo fixed that yest got two new ones and put a 2g manifold on i got saturday.

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

 

[miguelmcv]

What are you using to do the leak test?.
Are you using a compressor?.

If you are not using a compressor and have a big leak, You will never going to find the leak (for big leaks, air compressor is a must).

Do a leak test from the throttle body elbow, at this point you have to hear where the air is going to, Use a lot, but a lot soppy water, other wise you might not know where is leaking from,
If it still not getting compression, then remove all the vacuum lines and cop all the nipples at the intake, Including Booster and PCV, Make sure you check under neath the intake (gasket), Most of the big leaks are at the gasket, under neath the intake, and they are very, but very hard to track.

If you find a very tiny leak, Fix it, You have to fix it before doing another leak, other wise you will have more headaches to make some compression.

Do that and let as know how it came up.

 

[jcarmichael]

sounds good I just looked at my isc while I was on my 10 min break at work and had electrical tape around the end of the connector for it so last person that had the car might of spliced it which might not be a big deal but if find another one I am going to get the connector and all and redo that to be safe. but sounds good not sure I will be able to do the boost leak test tonight or not want to but having my daughter makes it a bit harder and using a compressor and the boost leak test i have two i built one with a 2.5 end pieceother with a 2 inch end piece.

ok I just measured my isc on my lunch break. all of them where 38 ohms and higher but no higher then 40 ohms. so according to the video all is good there. could my iacv becausing this issue how do you test for that?

ok so far I started at the throttle body and from what I found so far my bizz screw was leaking and i had some leaks at my throttle body where the egr use to be fixed all that still heard a leak but I didnt set my car to tdc so tomorrow night I am going to start there. and retest sorry for the run ons. trying to type this real quick so I can get my daughter to bed.

 

[jcarmichael]

another update a month ago when I did my arp head studs and head gasket I thought I had replaced my tb gasket. according to the hard plastic feeling gasket I broke off my tb last night that was not the case and i still had the gaskets so replaced I replaced them. also my bov was leaking extremely bad at the bottom may have to get a different one that fits better to stop the leak.

 

[miguelmcv]

The 2g bov (where it attaches) was so poor design. I had so many problems even using T-clamp to keep it tight and couldn't seal the leak.

Try to go with a hard pipe with a flange welded for a 1g or some other bov.

 

[yukiz]

check BISS screw, make sure it is not leaking from TB, leaking BISS screw will make adjustment gives vaulty reading on ISC.
Do a boost leak test too, very helpful before you do anything.....

 

[jcarmichael]

yea I am thinking of going back to the 1g stock bov i only push 14 psi tops right now. so the 1g bov will hold eventually ill have to get a better one but the aftermarket cheap one on on there right now isn't sitting flush it over laps the flange a tad bit also so its leaking hopefully the gasket i put on there will help for the time being though. also already changed my bizz screw o ring and tb gasket only thing really left on the tb that could leak are the seals but I don't think that is an issue. re checking it again tonight from tb up wanted the rtv to have time to set on the new gasket.

thanks again every one