car dies on decel?

[Alec]

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.

So as an added bonus, I got lucky and don't have stalling? I'm sure a number a factors also are taken into consideration such as driving style, temperature, humidity, etc.

 

[jdub]

So as an added bonus, I got lucky and don't have stalling? I'm sure a number a factors also are taken into consideration such as driving style, temperature, humidity, etc.

Correct on all, plus several more
The only reason I mentioned it is you've posted about the adjustment a couple times now...it's really not the primary factor for the atmospheric stalling issue.

Anyway, the OP has stated he has a stock BOV that is not leaking. Therefore, the BOV is not a factor in his problems...enough discussion on it.
This thread needs to get back on track to help the guy get his motor running in a useful manner.

 

[Moy]

Has the OP checked the AFM? I've had it unplugged before, and when I go to rev the engine it would cut out. I've read the OP's (and brother's) previous statements and I did not see anywhere that they checked the AFM. Always worth it to cover all bases.

 

[jdub]

Has the OP checked the AFM? I've had it unplugged before, and when I go to rev the engine it would cut out. I've read the OP's (and brother's) previous statements and I did not see anywhere that they checked the AFM. Always worth it to cover all bases.

I agree, but he's not throwing a code...a bad AFM connection should do that.

 

[Zazzn]

check the ISC diaphragm to make sure it's not broken i replaced mine and all was good

 

[mako18]

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.

We are using a cooleeze hard pipe. New couplers and clamped down good. I will also go over the i/c piping I may even pressure test it under water piece by piece.

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

Yeah I will double check and take some pics.

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.

Yeah that has got to be the main issue. I think? I was told by PO of this car he had the same problem and had to pre-advance (make sense?) the cps in order to get it to adjust so it would idle and not die. He said around 20*advanced adn he had a high idle. I am not doing that there is always a reason why something is off and I want it done right!! This is my brothers car so even more important to me that its correct.

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.

Did that and got a code 51 as stated.

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 was just making sure there wasn't a check valve in the rubber hose. Like a brake booster hose would have. I understand the system now.

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.

Will do!!

 

[mako18]

Has the OP checked the AFM? I've had it unplugged before, and when I go to rev the engine it would cut out. I've read the OP's (and brother's) previous statements and I did not see anywhere that they checked the AFM. Always worth it to cover all bases.

afm is good tested with a spare no difference.

 

[mako18]

UPDATE!!! She now does not die or surge at idle. Problem was timing as thought. I reset base timing @ 10* after adj. the cps. I had aligned the finger on the rotor with the pick up point. basically I was off a couple teeth again. Now it reflects the above photo. Jumper wire off it runs 14* just like it should. A quick rev to 3500 rpm let off throttle comes back to idle perfect!!! My brother was smiling ear to ear. He has worked his tail off funding this project once almost junk yard car. He saved it!!!

and now...

New problem. It does not like 1/8-1/4 throttle in any gear when less than 2200rpms. Almost dies then catches its self after falling 300-500 rpms and makes the car buck unless I give it more throttle. Now I don't have to move the throttle much just a slight increase. Anything past 1/4 throttle or 2500 rpm its drives fine.


I will research this new problem now I don't expect hand outs every time but figured I would mention it since you guys are being so helpful!! Thanks to you all by the way. Very much appreciated!!!

 

[jdub]

Pull the EFI fuse (>30 sec) to reset the ECU. Check for codes again after you run it.

Check the accordion hose again for cracks/leaks. Make sure the hoses to it are secure.

Have you checked fuel pressure?

Good to see you got it running

 

[mako18]

Will pull the fuse and check for codes.

Cooleeze pipe atm we borrowed one from a friend. I am going to make a couple hard turbo inlet pipes of similar design waiting for material to arrive. I still can't believe there are not any intakes available for a reasonable price.

Need to check fuel pressure also. I plan to change fuel filter first.

 

[GrimJack]

Fuel filter is a PITA to change, but pretty simple to test - all you need is a bucket and a stopwatch.

They are rarely a problem. As a matter of fact, I've never, *ever*, seen one that needed to be replaced on a Mk3.

 

[StrikeIS]

I am having the same problem with mine, with the 1/8 - 1/4 throttle. mine drops at 1900 down to about 900 -1000. I havent had the money to buy a new TPS and I dont know any one in the area with a supra that I could use theirs so Im stuck for now.

http://www.supramania.com/forums/showthread.php?t=106601