Nilo987 Posted July 21, 2012 Report Share Posted July 21, 2012 Hey guys, Starquest newbie here, just got it a few days ago and it runs great other than a slight issue when it's been driven awhile. Usually when I'm going 55mph it does a barely noticeable bucking, if I let the speed go down to 50, no bucking. Turbo gauge usually reads in the negative when it does this barely noticeable bucking. Only known mods I know are done on this car is the turbo was turned up to 14lbs of boost, and the previous owner as stated in his ad "the exhaust manifold gasket was just replace, as well as the spark plugs and wires, new aftermarket 3" downpipe and o2 sensor". I'm running 89 octane gas in it, it has 87k original miles, 1988 Conquest TSI. Quote Link to comment Share on other sites More sharing options...
Starfighterpilot Posted July 21, 2012 Report Share Posted July 21, 2012 What does the engine do when you hammer the throttle wide open? For What It's Worth. KEN Quote Link to comment Share on other sites More sharing options...
TexasQuest Posted July 21, 2012 Report Share Posted July 21, 2012 Check your vacum advance. Quote Link to comment Share on other sites More sharing options...
GLHS Posted July 21, 2012 Report Share Posted July 21, 2012 Is the car 5 speed?also let someone else comment but i think 14psi is high to run 89octane Quote Link to comment Share on other sites More sharing options...
tankbob Posted July 22, 2012 Report Share Posted July 22, 2012 Im running stock boost on 91 octane, Im pretty sure that is what the factory recommends. Quote Link to comment Share on other sites More sharing options...
Nilo987 Posted July 22, 2012 Author Report Share Posted July 22, 2012 What does the engine do when you hammer the throttle wide open? For What It's Worth. KEN It stops bucking and goes fast when I hammer it. When I first got it the only gas station around had 87 octane only. So I put some of that into it, when getting onto it when I had the 87 octane it stuttered hard when I tried accelerating hard. Once I switched to 89 it quit the stuttering when flooring it, but when cruising at 55 in fifth it does the barely noticeable bucking. Is the car 5 speed?also let someone else comment but i think 14psi is high to run 89octaneYea, it's a five speed, and out where I live I've only seen 89 octane as the highest I've seen so far. Might have to check another couple gas stations I haven't checked yet. Check your vacum advance.Where is the vacuum advance, know it's probably a newb question but Im a newb to turbo cars unfortunately. Quote Link to comment Share on other sites More sharing options...
Nilo987 Posted July 22, 2012 Author Report Share Posted July 22, 2012 Ive been thinking and there could be another reason the car was doing the bucking, there's two little hoses that are right where turbo meets the air intake. When I got the car the previous owner had both of them unhooked. Not hooked up to anything. I connected the longer one to the piece of the intake that sits above the engine. Would send a pic but the site is telling me I've reached the max upload limit. Quote Link to comment Share on other sites More sharing options...
ZacMan Posted July 22, 2012 Report Share Posted July 22, 2012 I'd also look at your emissions system if its doing it under cruise only. This is when your ECU will turn on the exhaust gas recirculation and air pump. Something wrong in this system could certainly cause a miss. Quote Link to comment Share on other sites More sharing options...
TexasQuest Posted July 22, 2012 Report Share Posted July 22, 2012 Where is the vacuum advance, know it's probably a newb question but Im a newb to turbo cars unfortunately. It's on your distributor. It's a round shaped valve thingy with a vacuum line going to it. Quote Link to comment Share on other sites More sharing options...
Nilo987 Posted July 22, 2012 Author Report Share Posted July 22, 2012 It's on your distributor. It's a round shaped valve thingy with a vacuum line going to it. Cool, thanks I'll check it out this evening once this 100+ weather cools down a few degrees lol... Quote Link to comment Share on other sites More sharing options...
TexasQuest Posted July 22, 2012 Report Share Posted July 22, 2012 Sheesh tell me about it. It was 108 here yesterday! Quote Link to comment Share on other sites More sharing options...
Nilo987 Posted July 22, 2012 Author Report Share Posted July 22, 2012 Sheesh tell me about it. It was 108 here yesterday!I don't envy you living in Texas lol, lived in Houston for 3 years,at least when I lived there it rained every three days or so. Been so hot here in Kansas I get excited when it's below 100 degrees here! Quote Link to comment Share on other sites More sharing options...
TexasQuest Posted July 23, 2012 Report Share Posted July 23, 2012 Yeah we don't get the rain up here as much as down on the gulf but we do get the humidity. Quote Link to comment Share on other sites More sharing options...
Ironside Posted July 23, 2012 Report Share Posted July 23, 2012 What plugs are you running?What's the gap? 7031 NGK is the correct plug to run, with the higher boost at 14 psi you might need to shorten the gap a bit. Quote Link to comment Share on other sites More sharing options...
Starfighterpilot Posted July 23, 2012 Report Share Posted July 23, 2012 What plugs are you running?What's the gap? 7031 NGK is the correct plug to run, with the higher boost at 14 psi you might need to shorten the gap a bit. ^ Great call!!! I'd also check ALL of the engine house vacuum tubing for brittleness, breaks/cracks or pin hole leaks. If you have any, replace it all. Check that your vacuum tubing for cruise control and the AC system coming off of the intake manifold vacuum nipple under the three vacuum nipples on the TB is hooked up. Also, I would definitely NOT run 14 PSI boost using 87 or 89 ethanol gasoline, especially in the summer heat. I would dial the boost back to 7.5 ( 5 speed) or at the max 10 PSi (auto tranny) which the factory boost settings were set at if you can only get 87 or 89 octane ethanol gas. What you STILL may be experiencing under load in 5th gear is engine knock and the knock sensor is dialing back your ignition timing cuz it's detonating due to the fact that 89 octane doesn't have enough "octane" in it to prevent this. IF YOU ARE RUNNING 14 PSI BOOST IN YOUR STARQUEST YOU HAVE TO RUN PREMIUM 92 OR 93 OCTANE GAS!!!!!! For What It's Worth. KEN Quote Link to comment Share on other sites More sharing options...
Nilo987 Posted July 23, 2012 Author Report Share Posted July 23, 2012 I checked all the tubing yesterday, all the hoses and stuff are good to go, checked the vacuum advance as well, it's fine. I'll have to check the plugs to see what kind they are and if they're gapped properly. And as mentioned earlier I'm a turbo noob. So I wouldn't even begin to know how to change the boost settings on the turbo. The car does seem to run better when driven first thing in the morning around 7a.m. as opposed to driving it in the hottest part of the day. Is there a tutorial on how to change the boost settings? Or should I just take it to a shop and have them do it? Thanks for all the help guys, much appreciated! Quote Link to comment Share on other sites More sharing options...
ZacMan Posted July 24, 2012 Report Share Posted July 24, 2012 Mine had a missing/bucking at around teh same rpm's your mentioning, at cruise. Rebuilding the TBI intake and removing all the emissions crap solved it. Quote Link to comment Share on other sites More sharing options...
tankbob Posted July 24, 2012 Report Share Posted July 24, 2012 I checked all the tubing yesterday, all the hoses and stuff are good to go, checked the vacuum advance as well, it's fine. I'll have to check the plugs to see what kind they are and if they're gapped properly. And as mentioned earlier I'm a turbo noob. So I wouldn't even begin to know how to change the boost settings on the turbo. The car does seem to run better when driven first thing in the morning around 7a.m. as opposed to driving it in the hottest part of the day. Is there a tutorial on how to change the boost settings? Or should I just take it to a shop and have them do it? Thanks for all the help guys, much appreciated! I checked all the tubing yesterday, all the hoses and stuff are good to go, checked the vacuum advance as well, it's fine. I'll have to check the plugs to see what kind they are and if they're gapped properly. And as mentioned earlier I'm a turbo noob. So I wouldn't even begin to know how to change the boost settings on the turbo. The car does seem to run better when driven first thing in the morning around 7a.m. as opposed to driving it in the hottest part of the day. Is there a tutorial on how to change the boost settings? Or should I just take it to a shop and have them do it? Thanks for all the help guys, much appreciated!Very simple, mine is just a rubber line that wraps around the front of the valve cover. At a point in the cord there is a break with an adjuster nut, turning the nut would add or lessen my boost. I dont know if mine is stock but its incredibly ghetto, you can get electronic ones. Quote Link to comment Share on other sites More sharing options...
Indiana Posted July 24, 2012 Report Share Posted July 24, 2012 I'd also look at your emissions system if its doing it under cruise only. This is when your ECU will turn on the exhaust gas recirculation and air pump. Something wrong in this system could certainly cause a miss.There's no air pump on this motor over here. Quote Link to comment Share on other sites More sharing options...
Indiana Posted July 24, 2012 Report Share Posted July 24, 2012 I checked all the tubing yesterday, all the hoses and stuff are good to go, checked the vacuum advance as well, it's fine. I'll have to check the plugs to see what kind they are and if they're gapped properly. And as mentioned earlier I'm a turbo noob. So I wouldn't even begin to know how to change the boost settings on the turbo. The car does seem to run better when driven first thing in the morning around 7a.m. as opposed to driving it in the hottest part of the day. Is there a tutorial on how to change the boost settings? Or should I just take it to a shop and have them do it? Thanks for all the help guys, much appreciated!How did you "check" your vacuum advance? Take the distributor cap off, put a short hose on the nipple and suck on it and the arm pulls in, cover the end of that hose with your tongue and the arm must stay in. If it moves back out the vacuum advance is bad and must be replaced. It will not retard timing under boost properly. Those missing hoses on the turbo, if two of the three were off and you had two open nipples on the wastegate actuator and you're looking only at a stock boost gauge you're really running more than the gauge says. The stock gauge isn't accurate and wasn't supposed to work as a pressure gauge its only an estimate from the MAF and tach signal. Its more of a gimmic. That bucking is the knock sensor working. It could be from too much boost too quickly, crap gas, misfiring spark plugs from using the wrong one, crossed and misfiring plugs from the plug wires touching and twisted around each other not in their holders to separate them. Quote Link to comment Share on other sites More sharing options...
Nilo987 Posted July 25, 2012 Author Report Share Posted July 25, 2012 (edited) How did you "check" your vacuum advance? Take the distributor cap off, put a short hose on the nipple and suck on it and the arm pulls in, cover the end of that hose with your tongue and the arm must stay in. If it moves back out the vacuum advance is bad and must be replaced. It will not retard timing under boost properly. Those missing hoses on the turbo, if two of the three were off and you had two open nipples on the wastegate actuator and you're looking only at a stock boost gauge you're really running more than the gauge says. The stock gauge isn't accurate and wasn't supposed to work as a pressure gauge its only an estimate from the MAF and tach signal. Its more of a gimmic. That bucking is the knock sensor working. It could be from too much boost too quickly, crap gas, misfiring spark plugs from using the wrong one, crossed and misfiring plugs from the plug wires touching and twisted around each other not in their holders to separate them.Ok, well I just thought checking it meant checking to make sure the hose on it was secure. Guess I'll try your mentioned method next for the vacuum advance. Thanks for the info:) As far as the bucking once I've properly established the vacuum advance is ok I'll get rid of the crappy 89 octane and put some 91 in it. Not as good as 93 but unfortunately there's nowhere around here that offers that high. Had to search to find 91 lol... That sucks that the turbo gauge is innacurate.. because it says I hit 14 a lot. Edited July 25, 2012 by Nilo987 Quote Link to comment Share on other sites More sharing options...
Indiana Posted July 25, 2012 Report Share Posted July 25, 2012 http://www.b2600turbo.com/images/distri4.jpghttp://www.b2600turbo.com/images/boostgauge1.jpghttp://www.b2600turbo.com/images/distri1.jpg Quote Link to comment Share on other sites More sharing options...
Ironside Posted July 25, 2012 Report Share Posted July 25, 2012 Use photobucket for your pictures its free and we can helpa little better. Quote Link to comment Share on other sites More sharing options...
Nilo987 Posted July 25, 2012 Author Report Share Posted July 25, 2012 (edited) http://i1258.photobucket.com/albums/ii540/nilo987/2012-07-24201818.jpg Excuse the zip tie plz:P It's just there until I get a proper clamp ring for it http://i1258.photobucket.com/albums/ii540/nilo987/2012-07-24201946.jpg First image shows the hose hooked up to the intake piece directly sitting on top of the engine, second pic shows the hoses, biggest one(not meaning the air intake itself:P but of the littler ones) in the pic is hooked up to intake piece directly above the engine, second visible hose below it is hooked up to the air intake itself, and the third hose on that same piece the other two hoses are on is just open to the air. Edited July 25, 2012 by Nilo987 Quote Link to comment Share on other sites More sharing options...
Nilo987 Posted July 26, 2012 Author Report Share Posted July 26, 2012 (edited) Checked the hose that went from the vacuum advance, it had a tiny little hole in it about the size of a ball point pen tip. *EDIT* After putting some electrical tape on the hole on the hose, and taking it for a spin, it drives smooth as butter.Only things that have changed since I drove it earlier are:-- Covered the tiny hole on the vacuum advance up with electric tape-- Filled it up with 91 instead of 89(barely had any 89 left in it)-- Temperature outside was about 106 when I drove it earlier, temp outside when I drove it during running smoothly was about 92 and the sun was down. I probably did too many different things at once to be able to tell what it was that was causing the bucking... I do know unless it's absolutely necessary I'm not driving it during mid-day when it's hottest. Coulda been the gas octane was too low... coulda been the pen tip hole on the hose, coulda been the heat. Edited July 26, 2012 by Nilo987 Quote Link to comment Share on other sites More sharing options...
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