james_starks Posted March 17, 2009 Report Share Posted March 17, 2009 i have an 84 with t3/t4 upgrade and maft. the problem im having is that when i accelerate hard then let off the throttle my car stumbles as if it wants to die. however under lighter conditions it idles just fine. i have no idea what is going wrong. oh i have reset the throttle position sensor yesterday with some improvement but it still wants to die. Link to comment Share on other sites More sharing options...
8starion7 Posted March 17, 2009 Report Share Posted March 17, 2009 i have an 87 but have the same problem with mine. i put a 17c, which is a t3 ,on and never likes to idle anymore. it could be a vac leak but not positive a boost leak test will tell you if you have a vac leak. Link to comment Share on other sites More sharing options...
Shelby Posted March 18, 2009 Report Share Posted March 18, 2009 get the engine fully warm'd up,, now screw in the sas adjusting screw with a screw driver untill the engine revs a little now back it off 1/2 turn,, also make sure the normal hot idle is at or above 850 now also make sure the bov isn't leaking at idle Link to comment Share on other sites More sharing options...
smallblock12 Posted March 18, 2009 Report Share Posted March 18, 2009 my shetland did that when i had my fidanza flywheel on it Link to comment Share on other sites More sharing options...
slow8988 Posted March 18, 2009 Report Share Posted March 18, 2009 I had this problem. but it was due to a bad fpr . if you are puffing some or lots of gray smoke then check your fpr. Link to comment Share on other sites More sharing options...
8starion7 Posted March 18, 2009 Report Share Posted March 18, 2009 I had this problem. but it was due to a bad fpr . if you are puffing some or lots of gray smoke then check your fpr. when your fpr went bad did it make it run really rich? because that sounds like that might be my problem Link to comment Share on other sites More sharing options...
Caliber308 Posted March 18, 2009 Report Share Posted March 18, 2009 (edited) get the engine fully warm'd up,, now screw in the sas adjusting screw with a screw driver untill the engine revs a little now back it off 1/2 turn,, also make sure the normal hot idle is at or above 850 now also make sure the bov isn't leaking at idle Couldn't it also be a ISC out of adjustment??? Adjusting screw set out too far not touching the nose switch on full decellaration. I know mine was a long time ago. When I had to stop fast, the car died on me. CALIBER 308 Edited March 18, 2009 by Caliber308 Link to comment Share on other sites More sharing options...
Shelby Posted March 18, 2009 Report Share Posted March 18, 2009 yes Cal it could be a lot of things some day i think i should get the entire FSM open in one copy /paste and incert it into every reply i make Link to comment Share on other sites More sharing options...
james_starks Posted March 18, 2009 Author Report Share Posted March 18, 2009 the motor is out of an 88 so the isc is disconnected i dont have a blow off valve. on the fpr if i dissconnected it it should idle high right. i put a vacuum gauge on it and the needle moves around 20. Link to comment Share on other sites More sharing options...
Shelby Posted March 19, 2009 Report Share Posted March 19, 2009 quote name='james_starks' date='Mar 18 2009, 04:11 PM' post='866012'] the motor is out of an 88 so the isc is disconnected ( ok theres your answer,,the ISc extends while driveing to prevent a completely close'd throddle when returning to idle,it stops the rpms arround 1200-1400 and slowly lowers the rpms to idle ) i dont have a blow off valve. on the fpr if i dissconnected it it should idle high right. i put a vacuum gauge on it and the needle moves around 20. ( nope the fuel pressure reg hose never see's vacuum, it is connect'd to the wrong port ) Link to comment Share on other sites More sharing options...
james_starks Posted March 19, 2009 Author Report Share Posted March 19, 2009 i looked the isc has two wire groups to hook up i only have connector to hook up what is the best way of fixing my problem Link to comment Share on other sites More sharing options...
slow8988 Posted March 19, 2009 Report Share Posted March 19, 2009 yes my engine was running way rich. I had to unplug main injector to restart engine. and it would idle for like 5 sec before having to plug back injector . at first I put a kill switch in for the main injector but I got sick of restarting engine, so I got the msd 2222 rrfpr for about 120 bucks. and that solved my problem. if your engine is flooding like mine then try the kill switch. I ran the switch to the dash so I didn't have to get out of the car each time. I also shut the main injector off at high rpm then as I let the rpms come down I flipped it back on. the kill switch costs a few bucks depending on how fancy of a switch you want to buy. anyway try it see if that helps. Link to comment Share on other sites More sharing options...
Shelby Posted March 19, 2009 Report Share Posted March 19, 2009 i think we're geting some where ,,what yr is the car, what yr is the ecu,, and you have an 87-89 inj houseing and injs on it ,,there is on main inj on the 87-89 yrs,, only a sec inj and a pri,, the 86 did not use an MPS sensor it did use an isc,, let us know exactly what you have and what your useing with it Link to comment Share on other sites More sharing options...
slow8988 Posted March 19, 2009 Report Share Posted March 19, 2009 I have a 88 station running with 89 ecu from my shp conquest . ported tb and intake man. running a 20g at about 12 psi. lightened fw. msd 2222 rrfpr . *DM 3 in exhaust to a borla muffler. also using my 89 igniter. I think that's it for my engine. Link to comment Share on other sites More sharing options...
james_starks Posted March 19, 2009 Author Report Share Posted March 19, 2009 i think we're geting some where ,,what yr is the car, what yr is the ecu,, and you have an 87-89 inj houseing and injs on it ,,there is on main inj on the 87-89 yrs,, only a sec inj and a pri,, the 86 did not use an MPS sensor it did use an isc,, let us know exactly what you have and what your useing with it car is 84, ecu is 84, motor is 88, it has the two injectors that pluse together i.e. cant take one clip off the car will die. i dont see a map sensor the problem i was having was the butterfly valve would stick shut. i look around in the stuff that came with the car and found the isc put it on and that kept the valve from sticking shut i dont know what year the isc came from. is it just me or is pre 86 harder to find info about. i looked for the service manuel but itsaid that its currently not available. thanks for the help Link to comment Share on other sites More sharing options...
Shelby Posted March 19, 2009 Report Share Posted March 19, 2009 the system has to have a MSP sensor,, go to the garage and down load the 84-86 fuel suplimental manual and read it Link to comment Share on other sites More sharing options...
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