HELP, Car dies when breaks are applied!

[GNJoe86]

Ok so this has happened even when I had a power master unit on the car but now I have vacuum breaks. Basically only sometimes when breaks are applied (not hard) the car just dies out as the rpm's drop. What do you guys think, Aic problem? Vacuum leak? Anything else?

Thanks, Joe

 

[BlackBandit]

What chip do you have?

 

[ngnowner]

can you keep it running by feathering the accelerator? If not sounds like a screwed up security system/chip

 

[notacarlo]

Does the car buck/shudder?

 

[unix_punk]

I would guess iac first. You should be able to recreate it by only letting off the gas minus the brakes. If you can't do that then I would defer to other suggestions. Chip type is an important detail though.

 

[GNJoe86]

I have the Extender Extreme chip. It just happend twice tonight at exactly the same intersection im thinking that once it comes out of closed loop the iac is screwing up and it dies. So maybe a simple cleaning of the iac will do the trick. What do you guys think?

Thanks again, Joe

 

[ngnowner]

start simple

I have the Extender Extreme chip. It just happend twice tonight at exactly the same intersection im thinking that once it comes out of closed loop the iac is screwing up and it dies. So maybe a simple cleaning of the iac will do the trick. What do you guys think?

Thanks again, Joe

good place to start, then perform IAC reset procedure. I also had to fiddle around with the throttle plate screw a little, this is outlined in the procedure. IAC Reset Procedure

 

[GNJoe86]

ok so ill do the restart prosedure, but do you think I should remove the iac and clean it with some carb and choke cleaner and clean the hole with a tooth brush in the throttle body?

Thanks guys

 

[ngnowner]

yes clean first, then reset, then check MAF, vacuum leaks, etc......... before spending money on new parts.

 

[1991syclone]

Check what "notacarlo" said. It may be nothing but a convertor solenoid. You come to a stop and the convertor does not unlock and it stops the engine.

 

[unix_punk]

Check what "notacarlo" said. It may be nothing but a convertor solenoid. You come to a stop and the convertor does not unlock and it stops the engine.

A 200 4r cannot lock the converter in first gear... As soon as it downshifts the converter will be forced to unlock regardless of the TCC.

 

[cool 84]

A 200 4r cannot lock the converter in first gear... As soon as it downshifts the converter will be forced to unlock regardless of the TCC.

But the transmission sometimes doesn't downshift to first until you're almost stopped. When my solenoid went bad, it would always lug my engine down and kill it when coming to a stop. It was so bad that I unplugged the electrical plug so it couldn't lock up in the first place.

Try unplugging the electrcal plug from the transmission and see if that cures it.

 

[unix_punk]

I could see that I guess, mine was(is) bad and it never killed the car. I figured that if his TCC wasn't unlocking that he would've asked a question about why does the car shift up and down so violently...

 

[1991syclone]

Funny enough, mine went bad about 4 years ago and we looked at everything and finally got help from someone on the list and that was the problem. Car had no other problems, shifting or otherwise. Just every so often when I would slow down to stop the engine would load and die.

 

[TurboTerry87gn]

Try this: let off the gas let the engine idle down, then applie the brakes. If it doesn't die it probalby does point ot the IAC responding slow from carbon build up. My car use to do this before I installed my old FAST system and I just tuned the PID loop and idle down to correct for the lagging IAC motor.

I would try cleaning the iac and reset it as the others have mentioned.

 

[GNJoe86]

Ok guys confused. I tried to reset the iac with no luck the instructions say to set the idle at 500 +- 50 but the car wont stay alive at anywhere near 500 if it goes something around 700 it starts to shake and die. So with out adjusting the iac I did make sure the tps was at .42 and I took it for a ride and it has nothing to do with breaks. Basically if i let off the gas fast it dies but not every time. after I drive for a min and then let off the gas it dies and the restart is rough and I have to give it gas to keep it going. It seems like it is the iac but how the hell do I get that reset deal to work if the car wont idle at 500?

Thanks again guys, Joe

 

[TurboTerry87gn]

sounds like you have a fueling issue. too lean. My car wouldn't idle any leaner than 13.1 or it would surge real bad and become unstable. I could run it lean if I increased the idle speed to say around 950 prm, but chose to run it richer and aroung 700 idle rpm.

 

[GNVenom]

Get a scan tool on your car and check:

1. Battery volts when you apply your brakes (thinking there is a short in the brake light system, causing the voltage to drop and kill the engine - if the system drops to less than 9 volts, the computer will shut down).

2. Be sure the engine is in closed loop. The IAC won't play into the decel enleanment directly unless you're in closed loop. The IAC responds to idle properly in closed loop.

3. Look for your BLM numbers to be between 110 and 140. If your fueling is out of whack, the numbers will usually peg to the outer or inner boundaries and closed loop fueling control isn't possible. If this is the case, suspect the MAF or O2 sensors and also look for vacuum leaks, especially around the EGR - and check for a "stuck open" EGR.

 

[GNJoe86]

I have a scan master. I have eliminated the breaks from the problem, I am almost sure it is the iac but the adjustment procedure requires me to idle the car at 500 no car idles at 500rpm's to my knowledge. There has to be another way to set the iac.

 

[GNJoe86]

Ok guys I spent the last three hours toying with the car and I found out a few things. First I would like to say thank you to everyone who is helping me with this problem. I have the IAC set to the upper teens and the TPS set to .42 so all is in order with that. The car has a trans brake that engages when put into first gear so I used that to see how the car recovered when in gear. Even after the iac and tps were set properly every few quick revs would make the car die out. I upped the idle a bit to smooth the idle and it seemed to help but it still bogged when I gave it a quick rev. Do you guys think I should try a new IAC? Where do I get one? Any other ideas? Also I checked for a vac leak and there is none.

Thanks very much again, Joe