automech01 Posted September 1, 2011 Report Share Posted September 1, 2011 (edited) i need help in trying to find out why my car is not making any boost.it was boosting fine until one day it started to misfire and blow coolant out the exhaust i put on a new m-28 head on it and new injectors and a maft it has a new 19c turbo i can do a boost leak test to 10 lbs and any more it blows of the boost leak tester but when i drive it only shows 2 lbs of boost and the car has now power at all. the car idles smooth and responds well at all speeds just no power timing is set to 10 degrees btdc and any help will greatly appreciated. Edited September 1, 2011 by automech01 Link to comment Share on other sites More sharing options...
tg118 Posted September 1, 2011 Report Share Posted September 1, 2011 i had a similar issue, had no power boost only to 2lb, i changed everything turned out my(new) Convertor was melted closed inside... just an idea...disconnect the exhaust at the bottom of the down pipe and fire it up.... Link to comment Share on other sites More sharing options...
automech01 Posted September 1, 2011 Author Report Share Posted September 1, 2011 new exhaust no converter Link to comment Share on other sites More sharing options...
DMNDSTAR87 Posted September 1, 2011 Report Share Posted September 1, 2011 injector clips or bad tps maybe-----gig out Link to comment Share on other sites More sharing options...
NotStock88 Posted September 1, 2011 Report Share Posted September 1, 2011 any chance the dizzy is off a tooth? Link to comment Share on other sites More sharing options...
TRACK BEAST Posted September 1, 2011 Report Share Posted September 1, 2011 check the waste gate arm. Link to comment Share on other sites More sharing options...
Indiana Posted September 1, 2011 Report Share Posted September 1, 2011 Too many mods at the same time make for finding problems difficult. Did you have the block deck surface milled or did you flatten it yourself with a stone? They sag down in the middle and get low spots and that sag transfers right down and causes the crankshaff mains to be off and need line honed too. Heat cycles over 20 years the block changes. Were the head bolt holes cleaned out? No oil or coolant left in them? What headgasket did you use? Was the intake manifold off? The intake and throttlebody can both leak coolant into the cylinders. The intake manifold gasket must have a film of sealant around the water passages and the surfaces clean and flat just like the head to the block. People might not believe it or even consider it but stock intake manifolds can and do warp. If the intake manifold bolts are loose it can leak boost but when the coolant washes out gaps in the gasket you have to replace it. Boost pressure comes up and coolant pressure comes up and one is going to be greater than the other at some point. Is the cam using mechanical or hydraulic rocker arms? A BOV if you have one I seriously doubt can hold in 10psi pressure without some boost assist on the top to balance that boost pressure out acting on the piston making only the spring there doing its job. Hopefully its not a gasket issue and something easy like a BOV or intercooler hose the rest is just a tuning issue. Link to comment Share on other sites More sharing options...
automech01 Posted September 1, 2011 Author Report Share Posted September 1, 2011 the head gasket was a felpro 9116pt and yes the bolt holes were cleaned out but i did not deck the block . the intake was off because i installed a new head and all the other mods were done before the head was replaced and yes the bov can hold more then 10 psi. the two small holes in the tb were blocked of so i am not loosing coolant. the cam is a hydraulic one if i had a problem with the head gasket i would have 1 or more down cylinders or overheating and or over pressurizing the coolant system i have neither. the low boost issue happened before i changed the head the car was misfiring on 2 cylinders due the the head being cracked in the valve seat area i changed the head and the car runs and idles great coolant temp is normal just no bust Link to comment Share on other sites More sharing options...
automech01 Posted September 1, 2011 Author Report Share Posted September 1, 2011 check the waste gate arm.arm is working fine i checked it with my air gun and it opens and closes Link to comment Share on other sites More sharing options...
automech01 Posted September 1, 2011 Author Report Share Posted September 1, 2011 just did a compression test and i got 136 psi on all 4 cyl's a little low but there all the same not using or burning oil and not blowing oil out the breather and or dip stick. Link to comment Share on other sites More sharing options...
automech01 Posted September 1, 2011 Author Report Share Posted September 1, 2011 and i am getting 20 hg of vacuum. Link to comment Share on other sites More sharing options...
Indiana Posted September 2, 2011 Report Share Posted September 2, 2011 The wastegate actuator arm, pull it off the flapper arm pin and place it up next to that pin it hooks on. The arm needs to be about 1/8" too short to reach and that puts enough load from the spring in the actuator on the arm to keep the flapper sealed and let the exhaust go out the turbine wheel until the boost pressure acts against the diaphragm to overcome the spring load and cause the flapper to open and the exhaust flow to change and the turbine shaft rpms drop and lowers the boost level. http://www.b2600turbo.com/images/WGactuator.jpg Link to comment Share on other sites More sharing options...
automech01 Posted September 2, 2011 Author Report Share Posted September 2, 2011 The wastegate actuator arm, pull it off the flapper arm pin and place it up next to that pin it hooks on. The arm needs to be about 1/8" too short to reach and that puts enough load from the spring in the actuator on the arm to keep the flapper sealed and let the exhaust go out the turbine wheel until the boost pressure acts against the diaphragm to overcome the spring load and cause the flapper to open and the exhaust flow to change and the turbine shaft rpms drop and lowers the boost level. http://www.b2600turbo.com/images/WGactuator.jpgwill try that tomorrow what do you think about the compression test readings? Link to comment Share on other sites More sharing options...
Indiana Posted September 2, 2011 Report Share Posted September 2, 2011 The compression numbers you gave were fine. Link to comment Share on other sites More sharing options...
automech01 Posted September 3, 2011 Author Report Share Posted September 3, 2011 will try that tomorrow what do you think about the compression test readings?i adjusted the arm today and no difference on the boost just can't figure it out . the turbo moves very little up and down at the compressor wheel but no in and out and there is no oil anywhere in or out of the turbo and it only has 20 miles on the turbo it self if the turbo can make the boost is it possible the boost is going past the piston rings? Link to comment Share on other sites More sharing options...
Indiana Posted September 3, 2011 Report Share Posted September 3, 2011 Since you have a MAFT you should ask a question specific to those settings. You might not have enough fuel or the cam timing could be off or the ignition off. Was the MAFT on there before or is this all new at the same time? What injectors and fuel pressure you running for base, what pump, etc. Link to comment Share on other sites More sharing options...
Recommended Posts