22RE Random Slight Miss at Warm Idle

pinemind · 2019-08-30T17:10:26+00:00

Hi guys, I'm battling the standard "random miss at warm idle" issue on my 1985 22RE. I've done tons of reading across all forums, and have such replaced and tested items listed below already per the suggestions. No dead cylinder spark (remove spark plug wire test on each cylinder, follows appropriately), and it can run fine at warm idle for 10 to 20 seconds, then a random light miss. You can see below how I've categorized what I've replaced, tested, and what I plan on doing shortly. At a high level, I'll admit I haven't done anything from a fuel system/delivery perspective so those are high on the list to replace. But given the randomness, outside of a bum fuel injector, I don't think the fuel system has much to possibly contribute here. I have one observation, and I'm thinking I know the answer regarding the TPS. Seeing as these are idle related issues, I focused on the IDL-E2 readings, specifically the one that is not an infinite reading of resistance (0.57mm, <2.3K ohms). When I test this, I get infinite Ohms at 0.57 mm. The highest gap I can put in with the feeler gauge where I get a non-infinite Ohm reading is 0.50mm. Do you guys think that could be the source of the idle issues? I've ordered another TPS and will be properly adjusting it this weekend, but just wanted a confirmation, as there are still a lot of things I'm going to replace/clean per my lists below and I'd like to actually find the root cause to give back and educate. Any other insights would be great, given my lists below and explanations above. What I have replaced/cleaned: - All vacuum lines with silicone ones and new clamps - OEM plugs, wires, rotor, cap - Throttle body gasket - OEM EGR Valve - EGR gaskets (block and plenum) - OEM PCV valve, grommet, hoses - O2 Sensor (OEM Denso 4-wire for new LCE Header) - Full new exhaust/gaskets (LCE header to turn down, including cat) - 1 air intake elbow, all new clamps - All connectors cleaned with contact cleaner - Throttle body completely cleaned of carbon What I have checked (resistance/electrical) - AFM - Coil - Distributor pickup coil - Cold start injector - Coolant temp sensor - Cold start thermo switch - EFI/Injector Solenoid Resistor - TPS (IDL-E2 @ .57mm is off, may be a problem) - Shined light through all intake hoses and elbows to verify no leaks (still need to do spray test as outlined below) - Timing, on point jumpered and not-jumpered - No CEL's jumpered What I need to test: - IACV (resistance) - IACV (operation, coolant lines blocked?) - Vacuum/air leaks w/starter fluid (vacuum lines, intake gaskets, air intake hoses) What I am planning on replacing (in order, still waiting on gaskets for fuel rail/injector): - New OEM igniter, quick swap to see if this may be the issue since testing it per FSM is not so simple - TPS and proper adjustment - Rebuilt/flow tested fuel injectors - OEM fuel rail - OEM fuel filter - OEM plenum to intake manifold gasket