prototype78 Posted December 6, 2014 Report Share Posted December 6, 2014 (edited) Hello...yesterday I saw a gold starquest close to my work area and I started following him/her but after I made 3rd shift I saw thr light turning red and I didnt have room or time to pass it...so I pressed the brakes and my car just died...So today I decided to repeat what happened yestersay and it turn off on me againif I use motor only and shift and afterwards I do the brakes it wont die...only when I boost...any ideas what might b causing this?! Yes that golden starquest got away :-( lol Edited December 6, 2014 by prototype78 Link to comment Share on other sites More sharing options...
Squrlsquash Posted December 6, 2014 Report Share Posted December 6, 2014 someone smarter should chime in, but to me it sounds like an issue with the brake booster vacuum systemmaybe the one-way valve that stops boost from getting into the vac booster is having issues Link to comment Share on other sites More sharing options...
prototype78 Posted December 6, 2014 Author Report Share Posted December 6, 2014 Squrlsquash, thanks for your reply I just came from testing the car again but this time I unplugged the b.o.v thinking that would be the problem...but it wasnt..I told my dad about answer to it and we r going to check the brake booster in a few more mins...thank you Link to comment Share on other sites More sharing options...
Malykaii Posted December 6, 2014 Report Share Posted December 6, 2014 I'd guess that check valve or brake booster. Link to comment Share on other sites More sharing options...
prototype78 Posted December 6, 2014 Author Report Share Posted December 6, 2014 My dad put a sparkplug on one end of the brake booster hose and booster unplug...we drove around and I did the same thing...and car die after boosting and pressing brakemalykaii...what valve?! Link to comment Share on other sites More sharing options...
prototype78 Posted December 6, 2014 Author Report Share Posted December 6, 2014 My dad told me he felt my car running to rich and he lower the rpms to 800 (running before to 1000)...so I was wondering if I tune it with the maf-t and he did the idle manually..set up changes right?!...so u think it might be that? ...everything else is stock... Link to comment Share on other sites More sharing options...
Malykaii Posted December 6, 2014 Report Share Posted December 6, 2014 The one that Squrlsquash mentioned. But that doesn't sound like it with what you mentioned about bypassing the booster. Carry on... Link to comment Share on other sites More sharing options...
prototype78 Posted December 6, 2014 Author Report Share Posted December 6, 2014 I connected my wideband again and I notces in idle I was on 12.5-14...but when I was giving gas I saw numbers going to to 16 -17.5....I heard turbo spooling but I didnt changw shift ..just press brake softly so I think my car goes too lean and thats why it dies?! Link to comment Share on other sites More sharing options...
DieHARDmitsu. Posted December 7, 2014 Report Share Posted December 7, 2014 A loose accelerator cable and/or incorrect setting on your ISC/MPS servo can cause this too. Link to comment Share on other sites More sharing options...
prototype78 Posted December 7, 2014 Author Report Share Posted December 7, 2014 Hhmmm...we check accelerator cable and it was fine....isc/mps hasnt been check...ill give it a try tuesday since its going to be my day off... thanks for your replies guys Link to comment Share on other sites More sharing options...
prototype78 Posted December 8, 2014 Author Report Share Posted December 8, 2014 Tonight I drove it.....I saw my wb on idle my car is on 14 but now I hear the car spooling real fast...on 40mph my wd was on 16 and when I boosted and press brakes it died again...its annoying Link to comment Share on other sites More sharing options...
DieHARDmitsu. Posted December 8, 2014 Report Share Posted December 8, 2014 If you have a blow off valve on there, try disconnecting the vacuum line, plug the vacuum, take the car for a spin and see what happens. Link to comment Share on other sites More sharing options...
prototype78 Posted December 8, 2014 Author Report Share Posted December 8, 2014 Yeah I did that already...unplugged the bov and still died on me ... Link to comment Share on other sites More sharing options...
Starfighterpilot Posted December 10, 2014 Report Share Posted December 10, 2014 With the engine warmed up and idling at 800-1000 RPMS, disconnect the ISC and MPS barrel electrical wire connectors; take her for a ride and see what happens. What year is your Lady? This may be off the wall, but if shes an '87, it may possibly be the infamous '87 ignitor causing the problem. What does your dash volt meter read when you apply the brakes and she dies? For What It's Worth. KEN Link to comment Share on other sites More sharing options...
prototype78 Posted December 10, 2014 Author Report Share Posted December 10, 2014 Hello ken...yes when warm up the idle is 800 and she is an 87 already updated the ignition box with an 88-89 no more than 3 months ago, I also tried it with another ignition box and still does it too... volts shows normal but yesterday night I went for another ride...40 mins ride and no problem as long im not boosting n pressing brakes...I can boost and accelerate and no problem just when I brake after thr ppssshh loland still died on me...but when I tried to turn it on it didnt turn on...I had to turn off EVERYTHING to turn my car on...lights switch and fuel pump (yes I have a separated switch for pump) and then it turn on Link to comment Share on other sites More sharing options...
Starfighterpilot Posted December 11, 2014 Report Share Posted December 11, 2014 What voltage does your dash voltmeter read when you press down on the brake pedal without boosting? What happens when you suddenly let off of the gas pedal during boosting without hitting the brake pedal? Do all of your brake, turn & hazard lights work? What electrical system; wire color including tracer color; and EXACTLY where, did you tap into for your power supply to the fuel pump manual switch? Are you still using the fuel pump ECI control rely? If so where did you tap into the wiring going to it? Give us a page number for that system's electrical schematic from the FSM plus the location of the tap - ie between what connectors (they each have a unique alpha numeric identifier) or system components. If you are not using the ECI control relay how are you powering the fuel pump via the manual switch? Why aren't you using the relay? What other mechanical and/or electrical modifications does your Lady have? When was the last time (if ever) ALL (EVEN UNDER THE BATTERY TRAY) of the electrical connector's male & female metal terminals (including relays) and grounds were cleaned in the engine house? When were the FI clips replaced and are the fuel injector male electrical metal terminals shiney clean? What did your Dad do to get the idle down to 800 RPM's? What RPM's does your Lady idle at immediately after a stone cold start up? What did you find when you checked the ISC/MPS as I suggested in reply #14 above? Do you have any EFI ECU error codes? See the FAQ' on how to check this also see '88 FSM 14-49 & 14-50 Have you done a TPS/ISC reset per this Starquest FAQ http://www.starquest...showtopic=28069 ? BTW - You have a wierd unique problem. We need exact answers (NO text messaging short cut lingo) to all of the questions above or we can't even begin to help you cuz we don't have all of the information that we need. You have to do your homework and clearly define your answers to all of the above questions.. For What It's Worth. KEN PS - This may seem off the wall but it has worked many times in the past for me to correct wierd stuff happening electrically in my Old Broad. IF you found no EFI ECU error codes, try disconnecting the battery negative pole connector for about a minute, then hook it back up. This resets all of the Starquest computers - sorta like a hard computer reboot. Then take her out and see how she runs after boost and the brakes are applied. If shes still screwing up, take another set of error codes and let us know what you find. Link to comment Share on other sites More sharing options...
prototype78 Posted December 13, 2014 Author Report Share Posted December 13, 2014 Well my car is an 87 tsi I bought 4 years ago but 3 years ago I started working on it with my best friend...I replace many parts as previous owner had it running like crap I upgraded the ecu for 89 same thing with the ignition box and resistor, fuel pump walbro,3gm sensor n maft, fuel pressure regulator, new fuel filter in-tank and the one before the fuel pump, remove filter inside the hose, ss fuel lines by brian, new ps pump, new delphi injectors 650/950cc, msd2 , ovc pipe with ebay bov, new clutch master cylinder, slave cylinder, fidanza flywheel, and a new clutch stage 2 My volts are ready 13.5 once I turn it on and when it turns off after the boostyes all lights work properly , but somehow I noticed that if im running at night and dies after the boost...my car wont turn on if I do t turn off the lights. if I press gas and suddenly press brakes rpms will go low but wont turn off when p.o had this car he had some switches in this car and since I didnt know too much about witing on cars I tried to fix it, so I connected with key switch but I got used to it to hear first the pump so I took the line from fuel pump...follow the line after the connecror on the trunk...and I cut it attach the wire to it...connected to a fuse and fuse to switch..switch to ignition....I hear the fuel relay work but I also have the switch for security purpose since I dont live in a house . I did all grounds when I changed the wiring harness swap...replaced old rusty bolts and washers with new oneselectrical plus were clean and regreased too I replaced the cts on my car when I father step out the apt and he told me the car was running to rich so he regulated the idle on the engine , when we did the tune with maft we did it when engine was running on 1100 rpms...now my father lower it to 800rpms Also after reading it could be the brake booster my dad unplugged the brake booster on the hose side he plugged it with a sparkplug he had and everything was fine (he was a mechanic since he was 16 years old and when we came to this country 20 years ago he didnt want go work on cars but he helps me out from time to time) When I turn on car on cold it goes from 1200rpms and gradually goes down to 800 rpms Car runs good and strong as long I dont use the boost... I did my homework..lol thats why I came online looking for help . Ill do that...I have 3 89 ecus..ill try with another oneweird cause everything was working just fine before I put the new cts and my did the idle from thr cable side Link to comment Share on other sites More sharing options...
prototype78 Posted December 13, 2014 Author Report Share Posted December 13, 2014 Also I took the ebay bov off and removed the springs in it..and I noticed the piece that closes the bov get stock when returning to closing position. ..so might be the bov....hopefully Link to comment Share on other sites More sharing options...
prototype78 Posted December 17, 2014 Author Report Share Posted December 17, 2014 Today we found something we might think its whats giving me thid problem....wont be sure till tomorrow Link to comment Share on other sites More sharing options...
prototype78 Posted December 18, 2014 Author Report Share Posted December 18, 2014 No..it wasnt it...we found coolant on the intake runners...I have another tbi which ill put to see how it reacts...we cleaned the intake manifold new gaskets everything on it...new vacuum hoses ..and new 89 ecu Link to comment Share on other sites More sharing options...
freebird Posted December 18, 2014 Report Share Posted December 18, 2014 try running with all the vac. lines plugged off.That will eliminate booster and bov.drive it without the filter, so you know the maf isnt suckin the bottom of the filter.Is the egr eliminated?How much boost are you running? Link to comment Share on other sites More sharing options...
prototype78 Posted December 18, 2014 Author Report Share Posted December 18, 2014 Hey buddy..yeah egr has been deleted by previous ownerr and same with absrunning 7psi...ill do the filter thing now...thanks Link to comment Share on other sites More sharing options...
prototype78 Posted December 18, 2014 Author Report Share Posted December 18, 2014 K I removed the filter and turns on good ...I mean car runs good till I hit boost and brakes....yesterday I had a yellow light on me while on 3rd and press the brakes...the tach went low real fast to the point of turning off buti press gas to have it running Link to comment Share on other sites More sharing options...
questtuner82 Posted December 18, 2014 Report Share Posted December 18, 2014 Did you say that you are running a mass air translator and gm mas? Link to comment Share on other sites More sharing options...
prototype78 Posted December 18, 2014 Author Report Share Posted December 18, 2014 Watch "This is my problem 87 tsi" on YouTubeThis is my problem 87 tsi: Link to comment Share on other sites More sharing options...
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