88 Iron Duke will not start, but will idle (Page 2/2) theogre AUG 21, 09:33 AM Install a new/used pump but did you use J30R10 hose? If not then gas can eat other types and leak @ minimum. If you reused factory hose, was weak to start and likely failed. ⚠️ Putting high pressure pump in duke's tank often causes problems because high pressure and volume can "peg" the TBI regulator full open and still have too much PSI for injector etc to deal with. If you reused old duke hose for pump joint likely will fail w/ high pressure pump. ECM may have problems anyway from heat and other issues. Example: ECM must see ignition before running the injector... problem is ECM may see that and turn on injector but injector driver circuit have problem and injector get intermittent or no ground to run. Need a Noid light to check that ECM tries running the injector when won't start. Often You won't get a "code" and see nothing using a scan tool for iffy ECM. If sensor(s) or battery volts are unstable w/ key on, engine not started then maybe iffy ECM or power ground or both to it have problems. ECT charts for Ω See my Cave, Sensors Quick Ref DanMFiero88 AUG 30, 12:00 PM Thanks again! Fuel pressure is definitely not the problem. Noid light connected to injector power resulted in a dim, intermittent glow during start - and it will not start. Checked ECM and TBI fuses and both are good. theogre AUG 30, 01:47 PM Noid light dim etc then can be "dead" ECM. ECM can seem to work yet have crack solder joints and other problems and just one output doesn't work. Worse because of heat and little air flow. See my Cave, ECM Heat On top many old GM ECM has Factory Defect w/ "sealing paint" that cause problems too that can lift surface mount parts etc and "kill" the ECM. Years ago had 87 duke ran one day, cool off overnight, and won't start next day until replacing ECM. I had extra but old unit out of GrndAm so worked for some years... But... Now I'm waiting on Reman Cardone ECM right now because of "dead" ECM as one problem is while computer "ordering" the Radiator Fan On, does not ground the wire to turn on the fan. I save old sensors to test this and ECM Scanner "Sees" coolant hot and fan 1 On but isn't. And jump ECM plug to ground for this will turn on so isn't a wiring problem. If need one... AZ has Cardone ECM and currently big discount from AZ web ship to home. Return the core to any local AZ store to save money shipping a core. Save the PROM to install in the new ECM. DanMFiero88 SEP 01, 06:05 PM Thank you very much! I ordered a Cardone ECM from AZ. It arrived today. I transferred the PROM from the old to the new ECM. I disconnected the positive battery cable, installed the ECM, and then hooked the power back up. It cranked, started, and idled just fine. Did two more starts just to feel comfortable that there is consistent performance. Oh, and I used a Sharpie to record on the ECM's case when I replaced it, along with the Service #, PROM External ID, PROM internal ID, and that the PROM is original to the vehicle. That's all thanks to your PROM ID without a scanner page, Ogre. Now to put everything back together, then test drive to fill up and return the old core to AZ. Thanks again. theogre SEP 01, 06:20 PM Take a pic of old ECM and make sure you can read the label in the pic. Shapie and other "permanent" marking in metal and plastic can fade or otherwise not readable months to years later. DanMFiero88 SEP 01, 06:35 PM Thanks again, Ogre. Well, I didn't take a picture of the original label for that reason, but I sure will save it in my Fiero folder now! Patrick SEP 01, 08:59 PM Thanks for reporting back with your results. We always like to hear the eventual outcome!