speed racer Posted June 11, 2013 Report Share Posted June 11, 2013 (edited) discovered sat eve the ground wire that screw into the lower mount for the ECU on the kick panel was loose.that was the primary problem of the wiring harness it seems.once started it ran crappy so I decided to swap around injector connectors.with just the primary it will barely run.had troublke w the primary injector before so no surprise,will sawp in my new set when get the weird issue fixed.I unplugged the primary and and it sputtered a bit then cleared up nice and ran pretty smooth on the secondary.with what supposed to be the injector clip for the secondary.Don't think I tried to start and run with the primary clip on the secondary...prob should have but I was running and I was excited and checking everything else I could think of while had it running.I did use the DVOM and checked the primnary clip while it was unplugged and had 12ish volts the whole time as obviously did the secondary.the secondary just clicking away as if it was supposed to.I posted about this weird issue last week and just now had chance to get back to car.I took a couple video clips of it running as I described and will try to post soon as can...they will prob explain better than words here.it would resopond fine on the secondary till 2500rpm then it would act like it it a rev limiter but if I floored it for a second it would then rev past the 2500.Shelby here suggested that a shorted out TPS could cause both injectors to fire all the time.,but its putting out voltage so even if not great it does still work I think.The car is an 88 5 speed.mostly stock except for a 1st gen MAS and bypass valve.I have a new nsd blaster 2 coil,new wires and plugs.its a new rebuild with only a few actual driven miles on it.when first fired it up last spring it ran great I I just had a clutch issue to fix,I recently discovered and fixed a leaking TB.had coolant being sucked into intake so now that's been eliminated from passing thru the TB. also at one point I had the key 'on' but the car not running/.both injectors connected and the primary was clicking.it had been running but I shut it off just didn't turn the key off.I tink it needs an exorcist/priest or something.lol Edited June 11, 2013 by speed racer Link to comment Share on other sites More sharing options...
StarquestRescue Posted June 12, 2013 Report Share Posted June 12, 2013 A while back Johnny Wald had a car that both injectors were firing as it attempted to idle. The tps voltage seemed ok, but when he swapped it for another tps the problem went away. Since the secondary can be activated by tps movement as well as an air flow threshold. A bogus signal from either is suspect. Tps voltage should be checked at the ecu end of the harness as well. The car should idle about 50-60 hz of airflow. But neither of my volt meters will read it correctly. My better one does read it, but it corrupts the signal to the ecu and causes the car to idle slower and poorly. Link to comment Share on other sites More sharing options...
speed racer Posted June 12, 2013 Author Report Share Posted June 12, 2013 (edited) Thanks for the reply .will check the TPS voltage at ecu plug.didnt get chance to swap the MAS out.got home late and after a hot a.. day of welding at work....cold beer my best friend now.I know a stock TPS is impossible to get and the Hyundia one is close enough to work and not very expensive so may give that a shot.My only other thought on it tday was maybe during my rebuilding of the passenger side floor I accidently burnt part of the harness or some spatter got into the harness and causing wires to short against one another,I had most of the interior out..except dash and HVAc stuf. and had wiring covered with a sheet of this stuff we use at work to protect the robot and jig fixture wiring but even w all that sparks do get in places they shouldn't.I didn't weld very far up into the wheel well so if I did burn something it should only be in first ft or so of harness from the ECU.just a thought. my stock MAS was fine when I swapped in the 1st gen so hopefully it still is. Edited June 12, 2013 by speed racer Link to comment Share on other sites More sharing options...
speed racer Posted June 12, 2013 Author Report Share Posted June 12, 2013 went out to the car before too much beer and checked the TPS voltage at the ECU as you (starquestRescue) suggested.with the key 'on' but not started I got .38v with the TPS turned all the way CC.i turned it clockwise till it stopped and got .38v.......the same no matter what position I had the TPS turned.much better way to test than trying to poke probed into the plug under hood.so since the voltage didn't change is my TPS dead or atleast virtually useless?My guess would be a big YES.i don't have a home made code reader but will make one ASAP now that I got it to atleast run.I took down the ECU and unplugged...checked the arness as far up to the firewall as I could and seen no signs of where a spatter ball had burned thru the loom into wiring. Link to comment Share on other sites More sharing options...
Amonje123 Posted June 12, 2013 Report Share Posted June 12, 2013 Rock auto has OEM tps sensor $168 Link to comment Share on other sites More sharing options...
StarquestRescue Posted June 12, 2013 Report Share Posted June 12, 2013 What does the tps voltage do when you open the throttle?. It should varie smoothly between about .5 and 4.5. A t pin from a sewing or hobby store works good to check voltage at the plugs under the hood. Slide it in between the wire and the rubber seal. Than use alligator jumpers to hook up your volt meter. Link to comment Share on other sites More sharing options...
speed racer Posted June 12, 2013 Author Report Share Posted June 12, 2013 the voltage doesn't change,stays at 0.38volts and rockauto no longer has TPS for our cars.allready tried.had a listing but called to order and they are gone,not availale I was told:( Link to comment Share on other sites More sharing options...
Edde Posted June 12, 2013 Report Share Posted June 12, 2013 Car is an 85.5 so it's not a primary/secondary system right? Just thought it worth mentioning. Link to comment Share on other sites More sharing options...
StarquestRescue Posted June 12, 2013 Report Share Posted June 12, 2013 He said it an 88 in the first post? Link to comment Share on other sites More sharing options...
speed racer Posted June 12, 2013 Author Report Share Posted June 12, 2013 *shaking head*.....yeah...it's an 88.it shouldn't be running as it is.It did run properly and something broke,shorted out....idk what yet but it went from strong running fresh rebuild to sputtering black smoke beltching pain in the butt.the last time I did drive it was when I moved it a few blocks when I moved at end of febuary.it backfired a bit and was idling high ...around 3k.I got it to new place parked it and didn't mess with for a week or so while I got settled.idk if tt little bit of info is helpful or not but just thougt of it and so posted.gonna get out and swap 1st gen MAS for stock unit.will post again later if made diff or not. Link to comment Share on other sites More sharing options...
speed racer Posted June 13, 2013 Author Report Share Posted June 13, 2013 UPDATE ok..i put the stock MAS back in and now the engine is totally stock.did it change anyting or fix my wierd problem...NOPE.....not a bit so i'm eliminating the MAS from the wt.... is wrong equation.I did notice something while messin w it.i flooded it out on the secondary ofcourse and it wouldn't start up anymore.,will swap plugs...again later but while cranking if I pushed pedal down to floor the needle on the stock boost gauge would jump up from -14 vacume to zero then back when I let off the gas.does that mean anything?maybe I think.as if maybe the TPS is doing something though when tested last nite the voltage at the ecu plug never changed.maybe the sensors are all fine but the ecu has had a nervous breakdown.lol...thinking outside the box and honestly done w this stock TBI piece of 80's Japanese engineering.its go or blow time for this thing. Link to comment Share on other sites More sharing options...
speed racer Posted June 13, 2013 Author Report Share Posted June 13, 2013 Anybody? Link to comment Share on other sites More sharing options...
Edde Posted June 13, 2013 Report Share Posted June 13, 2013 (edited) Sorry, better get new reading glasses. Thought it said 85.5 Some of what you mention here could fit with a bad CTS. Specifically I point to belching black smoke, backfire, sky high idle. I have had one bad stock mas that's only bug was under quick and deep throttle where the stock gauge would swing way over and peg at the limit even though the real boost reading was within stock specs. When this would happen the car acted like it hit a fuel cut. Under light throttle it ran beautifully. Edited June 13, 2013 by Edde Link to comment Share on other sites More sharing options...
Shelby Posted June 13, 2013 Report Share Posted June 13, 2013 some one needs to verify the yr of the fuel system he has,, 55.5 or 88 , what ever also all injectors will show 12 volts at the inj clip , power terminal it's the ground side of the clip that the ecu controls causeing the inj to open or close,, sounds like some one has swaped in the wrong yr injs if the car is an 85.5 and the pri clip is on the sec inj if the system is an 88 and you need to use an iunj tester led lamp to verify that both inj terminals are pulseing if 88 ecu,, you can not simply swap in an 88 ecu, and it become an 88 system don't work that way Link to comment Share on other sites More sharing options...
speed racer Posted June 13, 2013 Author Report Share Posted June 13, 2013 The car is nan 88..everything about the car is 88.....pretty sure that's been covered in most all my prev post..ive had it for 18 fn yrs I think I know by now what yr it is and it had never been touched till I got ahold of it.both injectors are deff pulsing at idle.ots friggin possese and I need a priest with holy water and just figure it out myself.all ive gotten from here is mostly confusion but thanks for trying anyway.when I finally do get it straitened out I may post back and let ppl know just because they may have such problem with their cars.,it worked and ran fine then it didn't since I put it all back together...something shorted out or a wire broke somewhere....I just keep missing it,.maybe the ecu is fubar but still works enough to kinda make the car run.25 yr old electronics....anything goes. Link to comment Share on other sites More sharing options...
speed racer Posted June 13, 2013 Author Report Share Posted June 13, 2013 (edited) the tag under hood say its an 88 and the title says 88....its insured as 88 and it worked properly as it should back in January and feb when drove last...what other verification ya want/want a blood and dna sample too?lol... Edited June 13, 2013 by speed racer Link to comment Share on other sites More sharing options...
StarquestRescue Posted June 13, 2013 Report Share Posted June 13, 2013 (edited) All clear on the 88 part. It is an unusual problem that has never really nailed down. There was a guy with a mouse chewed harness a couple of years ago that shorted the two injector wires together. At least you have a volt meter and can find a given pin at the ecu. That puts you ahead of most guys.There are many inputs to the ecu that can be checked for having the correct input voltages. Continuity in the harness and shorts to ground or other wires can be checked. Every year the ecu's are a year older. At some point they may fail, and no one here really know how a partial failure would act. Ecu are cheep enough to buy and try About $65 used. Used tps are available as well and can be tested both on and off the car. Edited June 13, 2013 by StarquestRescue Link to comment Share on other sites More sharing options...
speed racer Posted June 13, 2013 Author Report Share Posted June 13, 2013 thanks starquestrescue.i do like your advice..i will get out and probe the injector outputs from the ecu this eve.it is a weird one and I been suspecting a wiring harness problem for a while.not fun to nail down.tho this eve my daily driver begs for the attention.if get to it this eve will probe the injector outputs if it will start again.i flooded it out last nite messin w it.it got 3 sets of plugs I been swapping out.a bottle torch burns off the gasoline pretty good.lol.originally I planned to go MPI conversion but had to divert $$$ to my current DD so that killed the MPI.I started a MPI intake outta mild steel...time to finish.that's a whole diff can of worms I realize but after headaches never ending w the stock system......i'm ready to jump.I don't want 400hp I just want dependable fun car and I don't believe it's possible w stock TBI system...not w 20+ yr old electronics. Link to comment Share on other sites More sharing options...
StarquestRescue Posted June 13, 2013 Report Share Posted June 13, 2013 The whole section is good to read through. Starting at page 14-55 the manual gives volt ranges you should see at the ecu. Start with the idle switch, isc voltage, air temp, baro, clt temp, tps. All inputs that can be checked with a volt meter. Disconnect the injectors and the ecu plugs and verify that the injector leads fro the ecu are not shorted together. http://www.starquestgarage.com/manuals/service/conquest/1988/88_conquest_service_manual_-_group_14_-_fuel_system.pdf Link to comment Share on other sites More sharing options...
speed racer Posted June 13, 2013 Author Report Share Posted June 13, 2013 (edited) Have read a few times.will check over next few days.could I possible just run new wires from ecu to resistor or injectors?thought about that tday.tat's if I discover a short of some knd.will give it a little more effort just cause I wanna know wt.... wrong but gonna get back to my MPI intake anyway.personally I feel my time more worth wild to abandon the stock mess and go for the conversion.i can work all the overtime I want at my job to afgford the standalone system.....the resource I don't have unlimited is time and have wasted a lot messin with a primitive system that even on a good day isn't great.these cars don't follow normal rules either.the rin has stopped and i'm almost outta beer so will get out and give it one last shot; Edited June 13, 2013 by speed racer Link to comment Share on other sites More sharing options...
speed racer Posted June 14, 2013 Author Report Share Posted June 14, 2013 update time.got it to run again and while idling on secondary with just primary clip checked secondary injector clip and no voltage.this after tugging and pulling harness trying every combo I could to get it to run on its own and me not have foot on gas pedal.somewhere down the line in the harness I got wires transffering current to where it doesn't need to be.side not.....my primary injector still has issues but that's another story......I haven't ;pinned out' the wires coming off the ecu plugs and won't unless this another dead end.just gonna unwrap harness on intake side back as far as needed to find the short.been suspecting this but finding not so easy.once I find and fix I will swap in the injectors I got from LOWER SHORES.he no longer had delphis so I have a set of LUCAS if that makes much difference.I haven't tried them since before I fixed the TB coolant leaking issue.if fixes great....driving I will go...if not,,,,,this stock TBI crap is going in the trash to join my trucks old quadrajet carb.........i'm done with it, Link to comment Share on other sites More sharing options...
Shelby Posted June 14, 2013 Report Share Posted June 14, 2013 update time.got it to run again and while idling on secondary with just primary clip checked secondary injector clip and no voltage.this after tugging and pulling harness trying every combo I could to get it to run on its own and me not have foot on gas pedal.somewhere down the line in the harness I got wires transffering current to where it doesn't need to be.side not.....my primary injector still has issues but that's another story......I haven't ;pinned out' the wires coming off the ecu plugs and won't unless this another dead end.just gonna unwrap harness on intake side back as far as needed to find the short.been suspecting this but finding not so easy.once I find and fix I will swap in the injectors I got from LOWER SHORES.he no longer had delphis so I have a set of LUCAS if that makes much difference.I haven't tried them since before I fixed the TB coolant leaking issue.if fixes great....driving I will go...if not,,,,,this stock TBI crap is going in the trash to join my trucks old quadrajet carb.........i'm done with it, dude this TBi is the simplest system in the world if you can't get a handle on it,, every thing else is gona have you totally lost ,,actualy it's so simplethats why most have problems with it,,they keep over complicating things untill they can't see a tree for the forest being in the way Link to comment Share on other sites More sharing options...
Drive-By Posted June 14, 2013 Report Share Posted June 14, 2013 The hitting a wall at 2500rpm is that driving or stationary? Link to comment Share on other sites More sharing options...
speed racer Posted June 14, 2013 Author Report Share Posted June 14, 2013 (edited) well then mr Shelby you come down and fix it for me.i will simple myself down a bit and either figure it out or junk it.end of story.I think i'm done here though....atleast for a long time.I do best when I tune everybody out so that's what I think I need to do. Edited June 14, 2013 by speed racer Link to comment Share on other sites More sharing options...
Shelby Posted June 15, 2013 Report Share Posted June 15, 2013 well then mr Shelby you come down and fix it for me.i will simple myself down a bit and either figure it out or junk it.end of story.I think i'm done here though....atleast for a long time.I do best when I tune everybody out so that's what I think I need to do. I have fixed 100's of these cars , with out touching them,,but it does take some learning on the owners part , first they must know what each part is and what it's job is and how it works in relation to the other parts once you get that down pat , it all falls into place ,,i'm not trying to be a smart tail,, but beleave me when I say you guys over complicate things ,, and NEVER assume a part is good PROVE it is Link to comment Share on other sites More sharing options...
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