Is this engine Speed density? I thought the 90 town cars were Mass air. Was that video of a warm start or cold. It's hard to tell exactly what's going on with the background noise but it looks like it ran well for about 30 seconds, started missing and then died.
Speed Density.
Warm start, but the computer was not 'freash', I had run it 2 times before, and the first time it runs better for longer, but ends up doing the same thing. The background noise is the shop exhaust fan for engine exhaust.
IDK how it goes from running to missing bad enough to kill itself is such short order. It has factory plug wires, lol. perhaps those need replaced? They say 1990 right on them.
what sytem are you running exactly? was it all from the same vehicle?
if your running a maf system with no air meter then its not gonna run well after warmup...generally wont run before so that does not seem likely.
but i cant see or hear what you have. so no way to tell.
but...code reader? a 40 dollar code reader isnt worth buying, not on an obd1.
i just switch the sto to ground and watch the check engine light light. did you hook up the light? if you didnt just use a test light.
checking the o2's at the pins where they interface with the pcm is what you want to do, at least you know they work off the car, plug them in and run the car and see what they are reporting at the pcm.
buying a fuel pressure gauge is what you want to do with obd1, not a stupid base tester imo as the money spent on the fuel pressure gauge is better spent, where base code retrival is free.
if this is a mechanical issue then you have one thing, if it is an efi issue, from what you have reported it seems its all in closed loop.
so map sensor will be key for sd and maf for maf.
what exactly do you have system wise with pcm code, and how did you wire it to the oem harness?
also, the spark plug test should be after a cylinder balance test which your pcm should run. do that test and get all codes so far before any reset, and then reset, run and recode.
this will go a ways towards isolating issues.
I am running SpeedDensity from a 90's towncar. STOCK, all from the same donor car, I got the whole car from the pick_n_pull.
I know which wire is the check engine light, I will have to wire a bulb to it.
I will follow some wires from the O2 sensors to the EEC, (when you say PCM do you mean EEC? engine computer?)
Fuel pressure gauge is on the list.
When does it switch over TO closed loop? What can I test to see when it is switching over?
I have my MAP hooked to manifold vacuum and plugged in.
I hooked up about 12 wires to the OEM harness. I have it all written on a PDF document, I could post/share it if I knew some way to make it available for public download. Otherwise you have to PM me your email and I can sent you my 'answer key'.
IDK what you mean by spark plug test, (Pull them off one at a time and see what changes?) and IDK what a cylinder balance test are either.
THANK YOU GUYS FOR YOUR HELP AND INPUT!!
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were those the codes you retrieved?
