car dies on decel?

[daddydrew]

well i just rebuilt my motor, i had a idleing prob and did my research and fixxed that but now when i rev it or even go to drive it, it dies out. in between gears anytime driving or just parked? it isn't throwing any codes and my timing is coming in at exact. a friend of mine said that my lightweight flywheel had something to do with it but im not to sure?
:1zhelp:
thanks for any help
drew

 

[MDCmotorsports]

What BOV do you have on the car Drew?

 

[daddydrew]

its just the stock one

 

[MDCmotorsports]

Need to check to make sure it is installed in the correct direction of flow.

Also check to make sure that it is not blown.

To do this, simply try to blow through it. If you can, its toast. Also, the stock BOV MUST be routed back to the intake hose, and not to atmosphere.

 

[Moy]

Also, the stock BOV MUST be routed back to the intake hose, and not to atmosphere.

Why is this?

I realize that the engine will stutter/stall out if the air isn't re-routed, but why does the stock valve have to be sent back into the intake?

 

[Alec]

Why is this?

I realize that the engine will stutter/stall out if the air isn't re-routed, but why does the stock valve have to be sent back into the intake?

It doesn't. I run a atmospheric BOV with no issues at all. I have my adjustment spring set pretty hard though, but I have no surge. I love the running rich in between shifts, the POP sound is awesome. I can't wait till I get my full exhaust, I might get a flame to shoot out, lol. jk

 

[rawmk3]

It doesn't. I run a atmospheric BOV with no issues at all. I have my adjustment spring set pretty hard though, but I have no surge. I love the running rich in between shifts, the POP sound is awesome. I can't wait till I get my full exhaust, I might get a flame to shoot out, lol.

Ummm please tell me your joking here, cause seriously it makes me want to take the hour drive to AH to smack you. You truely sound like a 16 yr old high school student who is acting cool in the parking lot after class.

The OEM bov must be routed back into the intake system between the AFM and the turbo because the AFM has already told the ECU that the air is in the system. So if you vent to atmosphere you will run rich as stated.

I once had a cracked line off my BOV to the accordian tube and the car would stall, shudder and in general run like hell anytime I would come to a light. Only way for me (having an auto) would be to put it in N, and hold the throttle open a little so the BOV would not pop open. Backing down the throttle slowly. Not the best way tho.

Without getting a MAP based system for your ECU, you really shouldn't vent your BOV to atmosphere. But if you so decide to, plan on this happening more.

 

[Moy]

It doesn't. I run a atmospheric BOV with no issues at all. I have my adjustment spring set pretty hard though, but I have no surge. I love the running rich in between shifts, the POP sound is awesome. I can't wait till I get my full exhaust, I might get a flame to shoot out, lol.

Ummm please tell me your joking here, cause seriously it makes me want to take the hour drive to AH to smack you. You truely sound like a 16 yr old high school student who is acting cool in the parking lot after class.

I agree...

 

[RazoE]

It doesn't. I run a atmospheric BOV with no issues at all. I have my adjustment spring set pretty hard though, but I have no surge. I love the running rich in between shifts, the POP sound is awesome. I can't wait till I get my full exhaust, I might get a flame to shoot out, lol.

say bye bye to your spark plugs and your catalytic converter..

 

[daddydrew]

well i checked the bov and its just fine. when i rev it just sitting up to 2k rpm's when it comes back to where it should idle it just drops and dies it doesn't even try to catch itself. it flatout falls on its face..


also i do have the bov recirculated. all new hoses, no leaks, of any kind, still no codes most are factory hoses the ones that aren't arre so tight that they would just fit fittings. and my vaccum is sittin at 20 on my boost gauge

checks iscv, cps, and also tps... still wondering



please and thanks to any help
drew

 

[Alec]

Just so you guys know, this is how I bought the car. The previous owner who has had 13 Supra's set it up like that and he had no issues either. He agrees with me and said he likes the sound. He's knows a lot about these cars, btw. The flame part was a joke. Once again, I have no issues with stalling or sputtering and neither did the previous owner. I'm not running the stock BOV, I have a Greddy Type-RS.

 

[MDCmotorsports]

Drew. Have you reset the ECU any time here recently? Have you taken the car for a 15 minute drive since you did?
Also, have you checked for boost leaks? If you did - how did you check?

 

[mako18]

OK, I am Drews brother Darryl. We rebuilt the motor as stated. Purchased brand new cylinder head stock specs inspected by two machine shops for good measure.

So far I have done the following:
I have calibrated the tps, checked for vacuum leaks numerous times, bov is recirculated & tested, checked iscv but not with a meter (rain!!). grounds cables are all new and there are now 4 of them, grounded the head to chasis, block to chasis, head to block, motor mount to chasis. All is good.

No boost leak check yet. We are not building any boost according to the boost gauge (aftermarket) we still need to take it out and seat the rings. I don't want any positive pressure until then.

One issue we did have was setting ign. timing. After setting the no.1 piston to tdc on the compression stroke with cam gears aligned with the marks on the timing cover and crank set a 0*. Double check the intake lobe was facing upwards looking through the oil filler cap. Everything dead on!!! checked multiple times!!

Next jump terminals te1 -e1. Break out the timing light slip the inductive pickup over the no.1 "hotwire". proceed with setting the btdc. I realized the cps was off since I was getting min. adjustment when rotating the cps, after inspecting the cps postion I was off a tooth or so. The max. adjust we get now after aligning the cps properly is btdc is 8* then it runs 10* with the terminals te1-e1 not jumped. Cps looks dead on now looking at the rotor and pickup. I have checked timing several times to see if the belt skipped a tooth.

I just went out and unplugged the tps. I read it should idle up to 1500-2k. Now the idle surges up and down from 300-550 rpm. Bad tps? why/how would calibration be accurate? With it plugged in it will hold 750 then starts surging 900-400 rpms.

Also regarding the pcv hose to the intake, is the valve in the hose or is it built into the TB? we are using heater hose from the parts store we need to order a few more factory hoses from the dealer. I will feel stupid if this is the problem.

I will break out the meter tonight and check alternator, ign coils, igniter, iscv.

Edit: yes ecu has been reset. still no codes. No 15 min drive it dies between gears sometimes even feathering the gas to keep it alive. It feels like ign. breakup.

 

[rawmk3]

OK, I am Drews brother Darryl. We rebuilt the motor as stated. Purchased brand new cylinder head stock specs inspected by two machine shops for good measure.

So far I have done the following:
I have calibrated the tps, checked for vacuum leaks numerous times, bov is recirculated & tested, checked iscv but not with a meter (rain!!). grounds cables are all new and there are now 4 of them, grounded the head to chasis, block to chasis, head to block, motor mount to chasis. All is good.

No boost leak check yet. We are not building any boost according to the boost gauge (aftermarket) we still need to take it out and seat the rings. I don't want any positive pressure until then.

One issue we did have was setting ign. timing. After setting the no.1 piston to tdc on the compression stroke with cam gears aligned with the marks on the timing cover and crank set a 0*. Double check the intake lobe was facing upwards looking through the oil filler cap. Everything dead on!!! checked multiple times!!

Next jump terminals te1 -e1. Break out the timing light slip the inductive pickup over the no.1 "hotwire". proceed with setting the btdc. I realized the cps was off since I was getting min. adjustment when rotating the cps, after inspecting the cps postion I was off a tooth or so. The max. adjust we get now after aligning the cps properly is btdc is 8* then it runs 10* with the terminals te1-e1 not jumped. Cps looks dead on now looking at the rotor and pickup. I have checked timing several times to see if the belt skipped a tooth.

I just went out and unplugged the tps. I read it should idle up to 1500-2k. Now the idle surges up and down from 300-550 rpm. Bad tps? why/how would calibration be accurate? With it plugged in it will hold 750 then starts surging 900-400 rpms.

Also regarding the pcv hose to the intake, is the valve in the hose or is it built into the TB? we are using heater hose from the parts store we need to order a few more factory hoses from the dealer. I will feel stupid if this is the problem.

I will break out the meter tonight and check alternator, ign coils, igniter, iscv.

Edit: yes ecu has been reset. still no codes. No 15 min drive it dies between gears sometimes even feathering the gas to keep it alive. It feels like ign. breakup.

Well actually the PCV system part you are discussing is off the throttle body, across both nipples on the valve covers, then over to the intakes accordian tube before the turbo to have a good draw on it. So I cant say for sure, but you may want to try capping off the nipple on the throttle body, and run the PCV lines to the accordian tube. Im not sure if that would have an effect on the vac draw of the throttle body tho. If you need the metal tube that runs from the nipples on the valve cover to both the throttle body and then to the accordian tube lemme know, I should have one in my shop. OEM one atleast.

 

[rawmk3]

Just so you guys know, this is how I bought the car. The previous owner who has had 13 Supra's set it up like that and he had no issues either. He agrees with me and said he likes the sound. He's in his forties, btw. The flame part was a joke, btw. Once again, I have no issues with stalling or sputtering and neither did the previous owner. I'm not running the stock BOV, I have a Greddy Type-RS.

Unless your running a MAP based system, venting to atmosphere is still going to cause you to run way rich, which is also going to make you foul plugs faster, and fry your cat. And being that you live in arlington heights, I know for a fact you have emissions requirements to meet. And running that rich between shifts would make you FAIL. Atleast what a friend of mine who works at the emissions testing facility in hoffman est tells me.

13 Supra's? That guy has to be broke by now. And none the less you seriously sound like some kid in his tuner up at streets who thinks he is hot shit.

Your stating your adjustment screw was tight pretty much told us you were not using an OEM BOV. But please enjoy your car, and when you toast a set of rings cause your loading up on fuel between shifts, feel free to let us know. Hopefully I'll have mine rebuilt by then and I can laugh as I roll by and your on the side of the road with the hood up. Anything worth doing, is worth doing right.

 

[Alec]

Unless your running a MAP based system, venting to atmosphere is still going to cause you to run way rich, which is also going to make you foul plugs faster, and fry your cat. And being that you live in arlington heights, I know for a fact you have emissions requirements to meet. And running that rich between shifts would make you FAIL. Atleast what a friend of mine who works at the emissions testing facility in hoffman est tells me.

13 Supra's? That guy has to be broke by now. And none the less you seriously sound like some kid in his tuner up at streets who thinks he is hot shit.

Your stating your adjustment screw was tight pretty much told us you were not using an OEM BOV. But please enjoy your car, and when you toast a set of rings cause your loading up on fuel between shifts, feel free to let us know. Hopefully I'll have mine rebuilt by then and I can laugh as I roll by and your on the side of the road with the hood up. Anything worth doing, is worth doing right.

Actually, you are quite wrong as far as the emissions standards go. I've been living here for 15 years and I know that currently, if it's pre-1995, you don't have to go for emissions. Yes, that's right, 13 Supra's. He had 10 MK3's and 3 MK4's. His name is Pras, you might know him.

 

[jdub]

No boost leak check yet. We are not building any boost according to the boost gauge (aftermarket) we still need to take it out and seat the rings. I don't want any positive pressure until then.

An IC piping leak can cause all kind of mischief....even off boost. Check the accordion hose for leaks...air entering the system post AFM - pre turbo will cause problems. The rubber connector on the TB often is cracked as well.

One issue we did have was setting ign. timing. After setting the no.1 piston to tdc on the compression stroke with cam gears aligned with the marks on the timing cover and crank set a 0*. Double check the intake lobe was facing upwards looking through the oil filler cap. Everything dead on!!! checked multiple times!!

The CPS should look like this with the damper/gears lined up:

Next jump terminals te1 -e1. Break out the timing light slip the inductive pickup over the no.1 "hotwire". proceed with setting the btdc. I realized the cps was off since I was getting min. adjustment when rotating the cps, after inspecting the cps postion I was off a tooth or so. The max. adjust we get now after aligning the cps properly is btdc is 8* then it runs 10* with the terminals te1-e1 not jumped. Cps looks dead on now looking at the rotor and pickup. I have checked timing several times to see if the belt skipped a tooth.

Timing should be 10 deg BTDC with the terminals jumped. The timing index should increase to ~14 deg when the jumper is removed. Your description has it retarded.

I just went out and unplugged the tps. I read it should idle up to 1500-2k. Now the idle surges up and down from 300-550 rpm. Bad tps? why/how would calibration be accurate? With it plugged in it will hold 750 then starts surging 900-400 rpms.

TPS is likely fine, but do this: Jump the diagnostic block like you would checking codes and depress the gas petal. A code 51 should show with the pedal depressed. If it doesn't, you are not getting an IDL signal from the TPS...IDL is required to tell the ECU to be in idle mode.

Also regarding the pcv hose to the intake, is the valve in the hose or is it built into the TB? we are using heater hose from the parts store we need to order a few more factory hoses from the dealer. I will feel stupid if this is the problem.

Look here:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=EC&P=5

The PCV uses an orifice, not a valve. There is a hard line for on top of the cam covers....it must be connected to the TB and accordion hose on each end. A leak will introduce pirate air into the TB.

I will break out the meter tonight and check alternator, ign coils, igniter, iscv.

Check to see if the ISVC clicks full open on shut down. If the ISCV body has a lot of deposits on it, it can cause idle problems...clean it by removing the motor. Also look at the check valve under the ISCV...these can clog up as well.

 

[jdub]

Unless your running a MAP based system, venting to atmosphere is still going to cause you to run way rich, which is also going to make you foul plugs faster, and fry your cat. And being that you live in arlington heights, I know for a fact you have emissions requirements to meet. And running that rich between shifts would make you FAIL. Atleast what a friend of mine who works at the emissions testing facility in hoffman est tells me.

13 Supra's? That guy has to be broke by now. And none the less you seriously sound like some kid in his tuner up at streets who thinks he is hot shit.

Your stating your adjustment screw was tight pretty much told us you were not using an OEM BOV. But please enjoy your car, and when you toast a set of rings cause your loading up on fuel between shifts, feel free to let us know. Hopefully I'll have mine rebuilt by then and I can laugh as I roll by and your on the side of the road with the hood up. Anything worth doing, is worth doing right.

You are very wrong...you make it sound like a BOV to atmosphere will cause damage. It will not. Yes, you will get a momentary rich spike between shifts or when you let of the gas and the BOV opens. What you left out is the ECU will compensate...on an auto tranny, it will compensate to the point it's a rare event for the motor to stall. That is the worst that will happen...the engine can stall.

The rich condition will not "toast rings", "fry a CAT", "foul plugs" or any other long term problem. It damn sure will not cause an emission test failure...if the tech is running the car hard enough to enter boost on the dyno, he/she should be fired. It can cause a stall...that's it...an irritation and no more. The rich condition simply doesn't last long enough.

Bottom line on this: You demonstrated that you really don't have a clue on this issue, in addition to this post:

Well actually the PCV system part you are discussing is off the throttle body, across both nipples on the valve covers, then over to the intakes accordian tube before the turbo to have a good draw on it. So I cant say for sure, but you may want to try capping off the nipple on the throttle body, and run the PCV lines to the accordian tube. Im not sure if that would have an effect on the vac draw of the throttle body tho. If you need the metal tube that runs from the nipples on the valve cover to both the throttle body and then to the accordian tube lemme know, I should have one in my shop. OEM one atleast.

1) the turbo does not "have a good draw on it"...ever. Explain to me how any significant vacuum can be exerted on the system from the accordion hose?
2) TB vac is required for the PCV to work properly...capping the TB port is a sure fire way to screw it up.

Post crap/misinfo in the Tech section again and I will take appropriate steps to insure it does not happen again...it won't just be a post like this either. "I'm not sure", "I heard", "my buddy told me" are not acceptable and does not give you an out...if you are not 100% sure of your info, DO NOT POST. Got it?

In addition:

say bye bye to your spark plugs and your catalytic converter..

You also need to read the above ass chewing...it applies to you as well.

 

[Alec]

You are very wrong...you make it sound like a BOV to atmosphere will cause damage. It will not. Yes, you will get a momentary rich spike between shifts or when you let of the gas and the BOV opens. What you left out is the ECU will compensate...on an auto tranny, it will compensate to the point it's a rare event for the motor to stall. That is the worst that will happen...the engine can stall.

The rich condition will not "toast rings", "fry a CAT", "foul plugs" or any other long term problem. It damn sure will not cause an emission test failure...if the tech is running the car hard enough to enter boost on the dyno, he/she should be fired. It can cause a stall...that's it...an irritation and no more. The rich condition simply doesn't last long enough.

Thank you, that's what I thought. Besides, I have no ill effects with running my atmospheric BOV because it is adjusted properly. The only issue I once had was that the RPMs dipped slightly, but like I said, it only happened once.

 

[jdub]

Thank you, that's what I thought. Besides, I have no ill effects with running my atmospheric BOV because it is adjusted properly. The only issue I once had was that the RPMs dipped slightly, but like I said, it only happened once.

Alec - Adjusting the BOV correctly has very little to do with this issue. Since all BOVs dump coming off boost, even one that is adjusted properly can cause a stall if it is vented to the atmosphere. It's a function of the way the TCCS works, not the BOV. Some motors handle the momentary rich condition better than others...it depends on a number of factors. A properly adjusted BOV will simply hold boost to it's design spec to prevent compressor surge...nothing more.