86subieXT Posted November 7, 2011 Share Posted November 7, 2011 I had a problem while back i posted about dropping fuel pressure. apon acceleration sometimes it would bog out, almost stall for a second then come back. did some research and was told to check the fuel tank. The tank was full of crap so i dropped it and cleaned it out. then it got even worse. it would die when i would accelerate hard or make and positive boost. replaced the fuel pump. and it got a bit better but its still hardly driveable. Im stumped. not sure whats left to check. car is a 1986 XT turbo 4WD. 112,000kms no codes otherwise. Link to comment Share on other sites More sharing options...
bigjimd Posted November 7, 2011 Share Posted November 7, 2011 Fuel filter? Make sure all the fuel lines are clear? Link to comment Share on other sites More sharing options...
86subieXT Posted November 7, 2011 Author Share Posted November 7, 2011 replaced filter. blew out out lines with air hose. everything looks good. idles great. just looses it when i put a load on the engine. Link to comment Share on other sites More sharing options...
MilesFox Posted November 7, 2011 Share Posted November 7, 2011 does the car run great until it warms up? and then it is hard to start or runs crappy? try checking out the engine temp sensor located on the back of the intake near the turbo. This is likely your culprit. Link to comment Share on other sites More sharing options...
86subieXT Posted November 8, 2011 Author Share Posted November 8, 2011 i dont feel a change wether it is warmed up or still cold. it still bogs out. its not giving me a code. i dont see how the temp sensor would cause this. how can i check to make sure it is working? temp gauge functions. Link to comment Share on other sites More sharing options...
MilesFox Posted November 8, 2011 Share Posted November 8, 2011 this is not the sensor for the gauge, but the sensor for the ecu. if it is out of whack, the engine could run too rich, or too lean, or cause the idle air control valve to remain open or shut. the one for the gauge has a single spade terminal. the one for the ecu has a brown connector shaped like the ones on the injectors. the turbo engines are also finicky with the throttle position sensor. the contacts inside become corroded. you could try to remove the cover and clean the contacts. make sure you marrk the orientation of the sensor before you remove it. It can be dialed in with a multi-meter and range specs. also, check the contacts for corrosion where they plug into the sensors. Sometimes cleaning the contacts will improve considerably. Link to comment Share on other sites More sharing options...
86subieXT Posted November 8, 2011 Author Share Posted November 8, 2011 ill check those asap. thanks. Link to comment Share on other sites More sharing options...
idosubaru Posted November 8, 2011 Share Posted November 8, 2011 has the car ever run properly? maybe the timing belts are off? fuel filter ever been replaced? check fuel pressure at the engine. check fuel pressure regulator. check for spark? check distributor cap/rotor - i had one with issues and turned out the "new" cap and rotor were destroyed when i removed them. spray starting fluid around hoses/engine intake to check for vacuum leak. i've seen a couple/few distributors cause running issues without throwing a code for some reason. Link to comment Share on other sites More sharing options...
86subieXT Posted November 8, 2011 Author Share Posted November 8, 2011 Checked the TPS. was clean and functioned same plugged unplugged. car ran proper before. cant really pinpoint when exactly it started this. about 2 weeks now. check all the obvious things. when it got to fuel i ran around for the day with a fuel pressure gage on the car. every time it would bog the gauge would drop to Zero. i had the gauge before the fuel filter. thats why i thought fuel related. and why it would either fuel tank or pump. however missing spark or ignition would also explain the bog. but how would monitor while driving to see if it causes the bog. Link to comment Share on other sites More sharing options...
MilesFox Posted November 8, 2011 Share Posted November 8, 2011 fuel pressure regulator? The regulator is located aftehr the injectors on the return side. Try a fuel pressure test aft ehr the regulator and see what you get. Inspect the vacuum lines to it. The fuel pump runs from a signal put out by the disty when the car is running, or with the key turned. Make sure the green connectors in the trunk near the ecu are not connected. These are to remain disconnected during operation, and are for code diagnostics. The fuel pump relay is located near the ecu. Check the little nugget inside the top of the disty cap. Link to comment Share on other sites More sharing options...
86subieXT Posted November 8, 2011 Author Share Posted November 8, 2011 ill try a manual 12v source to the pump to make sure its not loosing any reading from the dizzy Link to comment Share on other sites More sharing options...
mwbean Posted November 8, 2011 Share Posted November 8, 2011 what isa disty cap?? Link to comment Share on other sites More sharing options...
MilesFox Posted November 8, 2011 Share Posted November 8, 2011 disty, dizzy: these are shorthand slang terms for distributor. Easier to type:burnout: Link to comment Share on other sites More sharing options...
86subieXT Posted November 8, 2011 Author Share Posted November 8, 2011 The fuel pump runs from a signal put out by the disty when the car is running, or with the key turned. The fuel pump relay is located near the ecu. Check the little nugget inside the top of the disty cap. I think you nailed the problem somewhere in there! when for a drive this morning with the new pump and the gauge and saw that the pressure would bounce constanlty up and down. while it was bogging. but iit wasnt bogging, i think it was actually missing. and if it missises and the dizzy controls the operation of the fuel pump then it was cause that pressure to vary like it was. Man, i hope that was a brainstorm moment. i guess i can get a timing light on it and see if its good. what is this nugget on the cap you speak of? Link to comment Share on other sites More sharing options...
86subieXT Posted November 8, 2011 Author Share Posted November 8, 2011 Oh lovely, its seems whoever replaced the heads on this engine never installed the timing plate. i cant check timing with a timing light. ill have to reset engine to TDC and guess on dizzy placement. ive done it many times on honda's. whats the best way to get crankshaft to TDC on a flat 4? Link to comment Share on other sites More sharing options...
john in KY Posted November 8, 2011 Share Posted November 8, 2011 The flywheel should also have ignition timing marks. There will be an inspection hole directly behind the throttle body. Link to comment Share on other sites More sharing options...
86subieXT Posted November 8, 2011 Author Share Posted November 8, 2011 okay i lined the flywheel to the 0 to match it with line. In this picture it shows the right side to have the dot on the bottom right and the right side shows the dot to be upper left on my engine is opposite right now. right side is upper left left side is bottom right. does that make any sense? flywheel is off 180* or timing is. Link to comment Share on other sites More sharing options...
86subieXT Posted November 8, 2011 Author Share Posted November 8, 2011 I think its too late. going to set this car on fire. reset TDC and it ran excactly the same. re checked compression. going to get another cap and rotor. then set it a flame. Link to comment Share on other sites More sharing options...
john in KY Posted November 8, 2011 Share Posted November 8, 2011 (edited) okay i lined the flywheel to the 0 to match it with line.In this picture it shows the right side to have the dot on the bottom right and the right side shows the dot to be upper left on my engine is opposite right now. right side is upper left left side is bottom right. does that make any sense? flywheel is off 180* or timing is. Doesn't make any difference. The distributor was just installed 180 degrees off. Plus if you rotate the engine one more full revolution, the dots will be where shown in the picture. Edited November 8, 2011 by john in KY Link to comment Share on other sites More sharing options...
john in KY Posted November 8, 2011 Share Posted November 8, 2011 I think its too late.going to set this car on fire. reset TDC and it ran excactly the same. re checked compression. going to get another cap and rotor. then set it a flame. Correct ignition timing should be 20 degrees BTDC with the green test connector located next to the ECU in the trunk connected. Link to comment Share on other sites More sharing options...
86subieXT Posted November 8, 2011 Author Share Posted November 8, 2011 so now that i have the timing like in the picture, does my distributor need to be rotated 180*? i can barely move the thing its so stiff, let alone pull it off. i ordered a cap and rotor for it. it was looking a bit used. still thinking about the fuel pump and how it is linked to ignition timing. Link to comment Share on other sites More sharing options...
MilesFox Posted November 8, 2011 Share Posted November 8, 2011 IF the timing was off 180, the car would not run. what i meant about the fuel pum p, is it is operating when the disty is turniong, regardless of its position or timing. The cam pulley dot on the passenger side will be in line with the hard edge of the valve cover when the #1 piston is at TDC, and the rotor will be pointing at the master cylinder, just to the right of the retaining clip/screw for the cap. Where did that diagram come from? I invented this timing trick myself, and now there is a diagram explaining the same thing? Link to comment Share on other sites More sharing options...
86subieXT Posted November 8, 2011 Author Share Posted November 8, 2011 sorry you confused my with that last paragraph. that diagram was from the service manual. Link to comment Share on other sites More sharing options...
MilesFox Posted November 9, 2011 Share Posted November 9, 2011 This best explains what i meant Link to comment Share on other sites More sharing options...
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