How to tell if my PCM is bad? NO DTC's but runs like crap

Question

Runs great in morning for 2 mins. Until run temp is reached. Then you press gas to go and it falls on its face. 0-50mph in 45sec. NO MILS OR DTC work done------ New plugs,coils,injectors,fuel filter,air filter, cleaned maf, new cat,new muffler, new o2 sensor,checked fuel pressure w/gage, cleaned throttle body.new exhaust manifolds,$200 have shop diagnose.

Answer 1

When you say there is no code being set, For Ford you have to do both a KOEO (key on engine off) and a KOER (key on Engine Running ) test to gather the code, This is almost like the TPS is being the culprit, . These have a high failure rate. If the PCM is bad usually it a no start condition where there is ignition spark  and no injector pulse. It is a very rare possibility that the ECM is running on its EPROM, that would be a indication that the ECM is bad, you would be able to remove the MAF connection during its idle and the engine would still be running instead of stalling out, another way is force a code on it disconnect the TPS while the engine is running or the ECT temperature sensor, and see if the CK ENG LT would detect a open circuit.

Comments

I've unplugged the Maf and it still drove.unplugged AIS AND GOT A PENDING CODE. In $6 on board monitor test of scan tool I get in test$10 " Not10 front switch ratio bank 2 fail I'd 21 what does that mean? Also in $5656"cylinder events test failed." ? When paid garage they said there's a slight misfire in cylinder 3

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All that is because you disconnected the MAF sensor , when the MAF sensor is disconnected there is no switch ratio. The 5656 this is the misfire count, There is no way the ECM is faulty. not when it detects a misfire event. That misfire depending on what is causing it is the culprit, a valve problem can cause the whole rough idle condition, The whole purpose of  the ECM is to protect the catalytic convertor, there is no way the CK ENG LT would not eventually come on, plus you are using Mode 6. that a tricky area,

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I'm using mode 6 because it's the only thing in the past month that has told me anything. I've spent thousands of dollars on this problem my dad was Nissan mechanic for 45 yrs and he has no clue either. I've changed just about every part I know. Until a DTC comes up I'm just throwing money away. Thanks for your help. I guess I'll go get raped at the ford dealer

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Mode 6 is tricky the reason once ypou clear the code it reset value that may not be true until its monitor runs. I know what you are talking about I have a Ford that start and runs really good then when it warms up it runs like crap, the code that set are EGR code but I block it off still no improvement. It says the camsensor out of timing, that not true. Any way this one has a engine miss, I took out the cylinder head and low and behold one of the piston is chip on the side, the compression test was good and even the leakdown test. a good ignition analyzer that gives a reading of the burn time and burn voltage. is the best conclusion. take out the cylinder sparkplug and not the difference. and does he engine when left to idle for at least 3 minutes does it burn oil?

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It's got an oil leak right now looks to be coming for the main pulley seal up front so it's hard to say if it burns oil. At this point w/ 160,000 mile and 18 yrs I just want the cat to clear IMS so I can sell it . Problem is I don't like ANY of these 6v turbo van that are out there now. They look like shoe boxes w/ marbles for wheels and their towing  past capacity is in question .This van problem consumed to much of my life already. The days I've spent wrenching on it I could be making money. Thank you for your help and will update if status changes.until then , no more racing Honda Accord for me. Lol