gottraction Posted January 23, 2012 Report Share Posted January 23, 2012 Ive searched and couldnt find a straight answer. I have purchased a 89 ecu for my 87 5 spd quest. i wanted to know did anything have to be done other than swapping the actual case. meaning its just plug and play correct? im having some major hesitation issues with my car still and there is only like 2-3 more things to replace. It was hitting a cut when i had the 1987 ecu. But it went away with the 89 ecu install. it just hesitates big time in 2,3. Almost like it cant keep up with spark. Link to comment Share on other sites More sharing options...
Starwolf Posted January 23, 2012 Report Share Posted January 23, 2012 Well yes it is directly plug and play. I think you should say more about your setup though. Are you running stock boost? Have you checked your vacuum advance? Could also be an injector problem. The ecu alone wont fix anything on a stock for stock running car. Unless you were running higher than stock boost. Link to comment Share on other sites More sharing options...
gottraction Posted January 23, 2012 Author Report Share Posted January 23, 2012 (edited) i was originally and it removed the cut. Iam on stock boost now to try and solve my problem and its still doing this mess. ignition coil is brand new. new plugs,wires, brand new vaccum advance and brand new trilogy injectors Edited January 23, 2012 by gottraction Link to comment Share on other sites More sharing options...
19cturbo Posted January 23, 2012 Report Share Posted January 23, 2012 Its not exactly plug and play, you have to swap the internals from the 88 to the 87 case, one mounts upside down Link to comment Share on other sites More sharing options...
gottraction Posted January 23, 2012 Author Report Share Posted January 23, 2012 yea i did that swap already Link to comment Share on other sites More sharing options...
Shelby Posted January 24, 2012 Report Share Posted January 24, 2012 try to be a little more spacific about your problem , amount of boost,, condition of vac advance unit,, base timeing,, have you check'd mechaincal adv for full advance and return to base oh and have you road test'd the fuel system pressures under boost Link to comment Share on other sites More sharing options...
bha280 Posted January 24, 2012 Report Share Posted January 24, 2012 I have only had 88's but don't you also have to swap in the knock box deal that's on the driver fender also? Link to comment Share on other sites More sharing options...
gottraction Posted January 24, 2012 Author Report Share Posted January 24, 2012 vaccum advance is brand new. distirbutor cap is new. vaccum advance is running to the front most nipple from the fron of the car. boost is almost 10lbs. stock wastegate. full exhuast. new fuel pressure regulator. stock 10degrees btdc. only thing i have no done is test the fuel pressure under boost. i want to but my days are short with this car. could a bad knock sensor cause this? Link to comment Share on other sites More sharing options...
StarquestRescue Posted January 25, 2012 Report Share Posted January 25, 2012 (edited) Yes a bad knock sensor could cause a misfire. If the knock sensor is bad or the wire breaks near the sensor or plug, the igniter will retard the timing 8* which could cause a miss with a marginal ignition or rich afr situation. The sensor is not enabled at idle so the base timing is normal. The service manual has a test procedure which says to disconnect the airflow meter to enable the sensor, not all cars will idle with the airflow sensor disconected though. Page 51 and 52 http://www.starquestgarage.com/manuals/service/conquest/1988/88_conquest_service_manual_-_group_14_-_fuel_system.pdf Edited January 25, 2012 by StarquestRescue Link to comment Share on other sites More sharing options...
StarquestRescue Posted January 25, 2012 Report Share Posted January 25, 2012 (edited) Another way to check the knock sensor. Disconnect the vacuum advance. Put a timing light on the crank pulley and watch how the timing advance as you rev the engine a little. Say to about 2500 should be enough. Than disconnect the knock sensor plug and repeat. It should act different, the timing will start to advance and than be pulled back some. If there is no difference ( the timing pulls back a little after it starts to advance) with and with out the knock sensor plugged in that is an indication of a problem. Reconnect the vacuum advance when done. Edited January 25, 2012 by StarquestRescue Link to comment Share on other sites More sharing options...
TheMoe Posted January 25, 2012 Report Share Posted January 25, 2012 I had a buddy buy a car that had hesitation issues at 3K. He had the primary and secondary injectors flow checked at three places, they all came back good. After about 3 months, one of his contacts that worked on classic cars finally traced it down to issues with the ecu (apparently the secondary injectors weren't firing). I gave him my 87 ecu to put into his 88 and it resolved his problem. Makes me wonder if it might be a flow issue? Link to comment Share on other sites More sharing options...
gottraction Posted January 25, 2012 Author Report Share Posted January 25, 2012 hmm i need to swap back in my 87 ecu then. thing is it kinda did it before it would just hit a cutwith the 87 ecu. I will try the vaccum advance trip starquest rescue today and post back what happens. im thinking its something with the knock sensor cause when i check it when i first got the car. one of the connecting wires was half spliced from the heat. I just thought it would throw a code if it didnt detect a knock sensor Link to comment Share on other sites More sharing options...
Caliber308 Posted January 25, 2012 Report Share Posted January 25, 2012 Ive searched and couldnt find a straight answer. I have purchased a 89 ecu for my 87 5 spd quest. i wanted to know did anything have to be done other than swapping the actual case No. Bill Link to comment Share on other sites More sharing options...
Caliber308 Posted January 25, 2012 Report Share Posted January 25, 2012 (edited) hmm i need to swap back in my 87 ecu then. Why? Was the 1988/89 ECU bad? Or is it because someone told you that someone else removed the 1988 ECU and installed a 1987 ECU???? Believe everything you see, and half of what you hear. Bill Edited January 25, 2012 by Caliber308 Link to comment Share on other sites More sharing options...
gottraction Posted January 25, 2012 Author Report Share Posted January 25, 2012 no no lol. i purchased a 1989 ecu because i know its a upgrade from my 87. i was going to purchase the knock box next. both ecus should be good i hope. im just trouble shooting from the post above from the guys friends problem Link to comment Share on other sites More sharing options...
gottraction Posted January 26, 2012 Author Report Share Posted January 26, 2012 checked the knock sensor and a good bit of the negative wire had become almost all the way undone. pulled it out and re soldered. drove it this morning. still hesitating badly. i will try to check the vaccum advance tonight. how fast can these go bad? also what vaccum nipple does it go to? Link to comment Share on other sites More sharing options...
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