Car stalls when trying to idle!! Video Included

[turbobird14]

Video in post 13

To start im very aware of the idle issues these vehicles have and this isnt one of those typical problems. Ill list my mods first:

16g turbo
SAFC
MTXL Wideband
FMIC
1g BOV Recirc'd
2g MAF
550cc RC's
BRAND NEW Throttle Body w/ FIAV Bypass and NEW IAC from [email protected]
Rewired OEM Fuel Pump

Ok, so basically when the vehicle is warmed up it has a hard time idling. It will sit right at 700-800 but dip down around 300 and sometimes recover and sometimes stall. When its doing this, my boost gauge really fluctuates and will read about 8-10 vac. At idle when its cold its sitting around 12, 14 max vac. It also acts like it has a boost leak cause it almost seems like is missing a bit, but I did a BLT and everything checked out fine! I made sure I wasnt gonna run into this issue so i deleted the entire vacuum system per the instructions on here: http://www.dsmtuners.com/forums/art...-speed-shop-vacuum-diagram-removal-1g-2g.html

The Wideband reads 14.7 at idle so i know im not way outa tune! What could be the prob? I pulled the plugs and took pics of the wear (newer plugs ~50 miles on them) and they all seemed fine accept cylinder 4 looked a little different. Ill post pics in a little bit. Any ideas?? Injectors or something fuel related?

Cylinders 1, 2 and 3:

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Cylinder 4: Slight Difference....maybe a little lean?

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[iBoostDSM]

Are your TPS, ISC, and BISS screw all adjusted properly. Vacuum at idle should be close 20 with stock cams.

If you read this and follow everything you should be able to sort out and idle problem.

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

 

[turbobird14]

Its a brand new TB, nothing needs to be adjusted because its completely rebuilt to OEM specs

 

[boost97gst]

Are your TPS, ISC, and BISS screw all adjusted properly. Vacuum at idle should be close 20 with stock cams.

If you read this and follow everything you should be able to sort out and idle problem.

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

listen up OP, he is right. Idle vac should be around 20 at idle of ~750 with stock cams. Either youve got a timing problem or somethings leaking bud. I believe your TB and sensors are all new but that doesnt rule out wiring to them. The plugs look ok to me, nothing way out of wack. Does it sound like its running on 3 or something? Pull one clip at a time. If your car doesnt want to idle, make it idle. Crank that biss until it goes up or easier still: tighten throttle cable ever so slightly so it will idle at 1500 or whatever so you can make sure all 4 are firing if youre worried about an injector.
Just a few things you can try but i would go back to what black gst said: Vac is way off, somethings not right.

When you deleted the lines i bet ya one of em is hanging loose.....

 

[koafallenangel]

What are those plugs gapped at? I had this problem because of poor spark. It should be gapped about 20. Also make sure they arent autolite because they dont work well in our motor NGK works really good.

 

[turbobird14]

listen up OP, he is right. Idle vac should be around 20 at idle of ~750 with stock cams. Either youve got a timing problem or somethings leaking bud. I believe your TB and sensors are all new but that doesnt rule out wiring to them. The plugs look ok to me, nothing way out of wack. Does it sound like its running on 3 or something? Pull one clip at a time. If your car doesnt want to idle, make it idle. Crank that biss until it goes up or easier still: tighten throttle cable ever so slightly so it will idle at 1500 or whatever so you can make sure all 4 are firing if youre worried about an injector.
Just a few things you can try but i would go back to what black gst said: Vac is way off, somethings not right.

When you deleted the lines i bet ya one of em is hanging loose.....

It doesnt sound like it running on 3...but its like intermittently hesitating, definitely not smooth. I have triple checked the vacuum lines and i swear they are all good, but it doesnt help to look again. What else other than a vacuum leak would cause the idle to be so out of whack?

What are those plugs gapped at? I had this problem because of poor spark. It should be gapped about 20. Also make sure they arent autolite because they dont work well in our motor NGK works really good.

NGK 1 step colder - gapped to .028 as instructed. I rechecked the gap yesterday after i did a quick pull and they were at .032 so i regapped them and reinstalled them.

ANOTHER NOTE - I did a base tune on my SAFC, got the low throttle points to where it cruises pretty nice and is pretty stoich, but my high throttle settings are at almost +28 hitting 11.4:1 AFR!!!!!!! WITH A 16G ON WASTEGATE PRESSURE!!! (remember 2g MAF and 550's) could low or inadequate fuel pressure be the cause of this all? Idling and everything?

 

[boost97gst]

Yea, the other dude is WRONG bzzzzzzzzzzz(thats the buzzer sound, fn dumb i know) You are correct: 28 is correct gap for stock. Higher boost=smaller gaps but i think youre fine.

The only other thing I can think of, well 2 things that would cause low vac are:
1: your timing is off
2: Unlikely, but ive seen it happen: the line from your vac source to gauge is leaky or the gauge itself is malfunctioning. Unlikely i know but im throwing possiblities your way.

Still have FIAV? EGR? Problems with either could cause unmetered air to get in but that usually leads to a high idle. I gotta say: Check your timing, just to be sure ya know/


Edit: missed part of your post. I would chase down the vac problem. You KNOW that exists. Then if you have afr problems it never hurts to get a gauge on the fuel line and see what idle pressure is. You can pick up a cheap afpr that works, i did. Even came with a gauge

Edit 2: this is not vac related but since youre a 1g you should have an idle switch. It is functional and wired right? Hard to tell without link, gonna need to break out the ecu pin outs and a meter probably

 

[WES_393]

Its a brand new TB, nothing needs to be adjusted because its completely rebuilt to OEM specs

You sure about that? How would the person who rebuilt your throttle body know exactly where your BISS needs to be? If they set it back to where it was, how do they know it wasn't adjusted in the past to compensate for previous idle issues?

 

[Abe'sGST]

Make sure your timing marks are dead on. Also check that IAC and BISS, I'm sure they're new but that doesn't rule them.

 

[turbobird14]

Gonna Check timing this weekend. Would that have any effect on why my high throttle settings are needing to be almost at +30?

 

[iBoostDSM]

There's no way to put in a BISS screw and throw on a TPS and have them set correctly without it being on the car. Having either of those 2 things off can make your idle very poor. Even though they are new, they still need to be adjusted for your application.

 

[boost97gst]

Without link getting the TPS and BISS set would be a pain, never tried it. But still, something else is up. max vac hes seeing is 14. Thats way off. I would expect -22in/hg w stock cams. TPS or BISS couldnt(i dont think) cause that massive of a vac drop.
Im leaning towards timing being off

 

[turbobird14]

Without link getting the TPS and BISS set would be a pain, never tried it. But still, something else is up. max vac hes seeing is 14. Thats way off. I would expect -22in/hg w stock cams. TPS or BISS couldnt(i dont think) cause that massive of a vac drop.
Im leaning towards timing being off

Here is a video of my boost gauge, wideband, and rpm's at idle to give you guys a little better feel of whats going on. Its loud cause im running open downpipe at the moment. The jump in RPM's is when i stab the gas a little bit to see if it would sputter and stall.....but it stayed running.

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[turbobird14]

I think everyone with the timing reply was dead nuts on...
Here is what the crank and oil pump sprockets look like

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And here's the cam gears!!!

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How did I not destroy something????

 

[iBoostDSM]

Definitley off, most of the time a couple teeth will be okay. It won't run right, as you experience, but nothing "bad" will happen.

 

[turbobird14]

So I decided to look in a random box of spare parts I've collected over the years to see if I had anything in there I could use: wow

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Timing belt installed tomorrow and hopefully get it tuned!!

 

[boost97gst]

woohoo! Looks like you werent(hopefully) far enough to bend valves. Might want to give it a leak down while youre changing the belt or realigning the old one. Just to be sure you dont have to take it right back off and pull the head. No sense in doing extra work. But you found it. Good job

 

[turbobird14]

Timing belt and pulleys installed and aligned!!! WOOOHOOO its fixed! Idles perfect.... 18 vac on the boost gauge, tuned it last night just to wastegate pressure and feels solid! Did a compression check and its +- 5psi across all cylinders! Thanks for all the input!

 

[boost97gst]

Im happy for ya bro. Congrats. Btw, you did the belt job and all the pulleys etc with the engine in the car? I have never had to change a tbelt but i swear i think id pull the damn engine to do it, it is TIGHT on that side! Anyway great news to have another member up n running

 

[turbobird14]

This is the first time i did a timing belt on a 1g, and honestly, I think everybody over exaggerates how difficult it actually is to do. I feel that alot of the intimidation of doing this job on your own is because everyone makes a big deal out of it. Start to finish took about 4 hours total, and about a good hour of that was because i had to make my own tensioner tool out of a long bolt that was threaded the wrong size for the hole. Its tight for sure but very do-able.