ok i converted my car to tpi.everything is fine except it dont start.tiny bit of starting fluid will fire right away.i checked for inj. pulse non there.figuring this is from bad ignition module cause send pulse to ecm if im correct.i looked at spark right away since this is suspect and is kinda weak but enough to fire up on starting fluid.think this is the culprit???im pretty sure this is the problem but if anyone was some advise let me know.thanks eric

 

ok changed module no change at all.tried jumping purple and white wire at module to fire injectors.works intermitantly kicks on fuel pump every time but every couple of times fires injector.when test light hooked in inj plug and jump wires and light will light really dim.my scanner says no vats fault but when cranking says vats fault.my chip has vats bypassed so i figure this may be normal but im not sure.im going to check inj ohms now.im getting pissed really quik now.2 weeks ago i converted a truck using all the same parts as we used on mine and fired right up.any help is definitly appreciated.eric

 

ok i checked injectors they all check good i think.said 16.5ohms on my dvom its auto ranging.i sprayed starting fluid in the t-body and it fired right away.it had inj pulse for a second when it fired then it died.i trying a pick upcoil now.its only 10bucks and im kinda getting frustrated.its 12 years old anyway cant hurt even if it doesnt fix the problem.anyone got any suggestions???? im kinda lost here.

 

Pretty tough on a swap to offer advice...

What year setup/ECM are you using?..i/e MAF or SD?

 

Yeap..We need to know what type of TPI system.. MAF or SD now on a side note, if it is MAF what year did the system come from?? It sounds to me like VATS problem, if this is 1989 to 1992 there is a good chance that this is your problem.

 

ok guys its a 91 sd tpi.im using the stock ecm(new)and a custom prom with vats removed.painless harness sd harness.i replaced the pickup and the module no change.i did find something odd though i sprayed starting fluid in it and it fired i let off the key and as it died it got pulse for a second.if i jump the purple and white wire and check for pulse i got it.i agree that it seems to be a vats problem.when key on engine off scanner says no vats fault when i start cranking it goes to vats fault.im getting real agravated with this.i just did one of these swapps not to long ago and that one fired right up.used same harness and supplier for the chip.i cant try his chip though cause his setup is maf.any advise is greatl appreciated.thanks eric

 

Do you have 12v on the injector harness?

There should be 12v with the key on, then the ECM will ground one side of the harness to fire the injectors.

Could it be the "pulse" you're seeing is actually 12volts, and not the "ground" state?

 

ok so good news is i go 12.05v at both terminals on the inj plug.bad news is i have no one here to help me see if there is a pulse showing with my dvom while cranking.as soon as someone gets here ill check it.thakns for the help guys.eric

 

got someone to crank for me while i checked some things.there is power at both inj terminals on the plug.it disapears as soon as you start cranking.both sides disapear no pulse what so ever.so i decided to check to to if pulse is going through purple and white wire from ignion module.nothing but if i jumper the wre to a pos.lead it fires injectors.also new thing i noticed scanner shows no cranking rpm at all and tach doesnt move either.thanks or the help so far guys.eric

 

You need distributor pulses for the ECM to fire the injectors...My assumption is the pulses should come from the ICM.

You should have receieved a wiring diagram with the Painless unit, verify that it's pinned correctly at the distributor to the ECM, verify continuity, make sure nothing is grounded that shouldn't be.

Also, verify ECM grounds.

 

just out of curiousity if there is no pulse for injectors shouldnt it not have spark?i had both pickup and module replaced had old module checked and checked ok.i been checking for continuty on the wires and all seem good.i checked the puple and white wire with a test light and got no pulse there no matter where i check but no matter if i jump it going to the ecm or icm it fires inj and kicks on fuel pump.oh yeah and painless should be more like painfull thier instructions seriously need to be rewritten.its like a universal harness book cover a bunch of harnesses.no pinouts or even diagram.and of course only open monday thru friday so calling them is out of the question.well i been checking pins with a diagram i found on here and looks like everything is correct.il recheck tomorrow and post result.eric

 

Ya know, I have a full schematic somewhere for a Painless SD harness, came witha TPI unit I bouhgt a few years ago...it's very complete.

Anyways, I know what you're saying, but I don't know the system well enough to say for sure, but I do know that if the ignition pulses are not detected, the injectors won't fire..also, I think it's the same rule for the fuel pump...i/e past the prime state when you turn the key on.

Your metion of the VATs thing has me wondering...I know VAT's disables the starter relay and the injectors...I wonder if it's done in parallel..i/e if one is disabled, so is the other one? If not, then it could be due to the disabling in the PROM...but I really am not sure.

Eventually, someone else has to chime in..I'll look for my Painless papers tomorrow, see if anything trips a light bulb.

 

thanks for the help 8mike9.this thing kinda has me stumped.i had called painless before i did anything to the harness to ask if some things could be removed from the harness and the said yeah just remove the wires from the ecm connecters.only things i removed was lockup,vss,pn switch,vats wire,egr sol.they said all that could be removed since it was of no use for me.they also said non of it should have any effect on anything since it wasnt being used.i also notified the chip burne about these thigns before and he said everything was good that painless was correct.i almost forgot about it.im wondering if something stupid is causing the problem.i read in the panless book that the 2 wires for pn switch should be connectd together if not using vss.im going to try t jumpe the terminals for this a little later and see what happens.thanks agai fo the help.eric

 

did some creative checking today.i had one thign i found that painless said should e grounded if not in use.i grounded it no change.i checked vats pin at ecm for anythig and if has 4.87 volts whih would probly be a 5v reference for vats unit if im correct.my question nw i guess is should it have power if vats is bypassed???im going to call painless tomorrow and howell(suppied chip)hopefully something gets accomplished out of some calls.ill postif i find anything else out.eric

 

All the injectors should have 12v on one side of them whenever the ignition is on and when you crank. If that voltage is going away when you crank, then that is your problem. You will need to trace out wiring to see where it is supplied from. It may come straight off the ignition switch and if that is the case, your are connected to one of the terminals which supplies 12v when the switch is on but 0v when you turn it to start. Find another terminal which is at 12v in both ON and START.

Good luck

 

i had everything apart today and rechecked everything.i even move the ignition power to a different source to double check that same thing.i ran continuty checks on all wires related to the problem.only thing i dont understand is why no pulse going into ecm from feed wire???purple and white wire is dead at all times if i jump either side it kicks inj. pulse.

 

Stevie brings up a good point, you should always have 12v on one side of the injectors at all times.

 

i do have poweron pink and black wire as long as the key is on or cranking.the other side has nothing though.i just got off the phone with painless and ent through some tests.they saying ecm is bad.i jumped the puple white wire from dist to harness and it sees no rpm on my scanner.they saying purple and white wire is doing its job cause fp kicks on but ecm isnt seeing it.duno im going to do some more checking.

 

ok me and my uncle checked some stuff today.everything did point to ecm so i tried a different one.same problem as before.so just for giggles i called painless back and told them the story.the gave me a couple more things to try and everything still points to ecm.so i guess the question is now is.can the prom be causing this problem.i got the car to run off starting fuild again and after the spark ignites the starting fluid and the rpms jump i have pulse width show up and rpm on my scanner,any other time i get nothing.so no so far today i ruled out ecm,and harness.now im lost,my uncle is lost,and the tech guys at painless are lost as well.i guess i really should add that joe at painless has been alot of help.very nice to deal with as well.anyone has any clue at all help a guy out here.thanks eric

 

Hmmn, no PW on cranking, but there is once it fires up?

Could be in "Clear flood state"...check the TPS voltage, I wonder if the wiring harness is incorrect and sending the referance voltage to the ECM? What's TPS voltage on your scanner say with the key on?

 

tps is reading .68 closed throttle wot reads4.28 or so.i got my own wiring harness print out from my work today and compared it to the one i had just to make sure everythign is the same then i rechecked all wires to the pins on ecm everything is ok.the problem seems to be that no inj. ground coming out of ecm.i hooked up a injector tester i made a couple years ago to each injector and everone works fine.node light doenst flash at all but sees to kinda dim instead of flash.ive used noid lights tons of times before and this isnt even close to a pulse.instead of flashing it just kinda dims slightly then gets brighter.also there is no rpm signal during cranking.if i fire it up off starting fluid when the engine catches for a secound then i get inj pw and rpm at scanner but will die once starting fluid runs out.if i crank on it right after the pw is gone and so is rpm.

 

Try disconnecting the injector harness at the injectors and ECM...check continuity between the plug ends for the ECM, make sure none are shorted to the 12volt side.

And you verifed all the ECM grounds are in good contact to the head, and ground from block to head to body/chassis is good?

 

ok i talked some to some people and basicly we was grasping at straws.we ended up checking everything on the spark side since seeing no rpm.i disconnected the jumper from the coil to the distributer and cleaned it really good on both ends.guess what now it has injector pulse.still isnt starting though plugs is soaked though.got new plugs tonight will try again tomorrow.the way it seems to me is the power and ground for the module go in through the wires i cleaned up.possible that it had enough going through to give weal spark but not enough of a signal to ecm to fire inj.hopefully it fires up tomorrow and ill be happy.its been a month since i drove this thing.thanks for the help everyone.ill post tomorrow if it runs and how good it is.thanks again eric.

 

see new post for no start no just wont fire