What have you done to your wagon lately? (Let's keep the thread going!)

There’s a member on here @cammerjeff who I believe knows a thing or two about those little pontiacs. I think he did something wild like stuff a v8 one? I could also be totally making that up. I tend to do that

 

Oh man. That’s a huge bummer. How did that scan tool work out for you?

 

Yeah, I was thinking about that when I saw the video.

 

It just arrived, but it didn't read anything. The connector's in the engine bay, so of course the terminals were corroded even when I had all of them connected. I also had to file the metal, but I broke one of the connectors while filing (not too surprising) so I had to use alligator clips. That didn't work either, but at one point I heard a relay activate. So now the one tester connector has to be replaced, too.

So... Now I'm still up a creek, but with enough knowledge to figure that a relay or more than one went bad. The fuel pump sends fuel up, but the car shuts off if I don't hold the pedal down. I think the Air-Fuel Mix isn't right due to me probably frying one or more relays, or the PCM itself if there is one.

Again, yes I do have two manuals for the car. But it would also be nice if I got this fixed sooner than later since the car's sitting outside, Halloween's not 3 weeks away, and my parents had some dumb kids vandalize the truck when we moved here around 2000.

If it is relays, that's not going to be a lot. I wonder how much a relay tester costs for this kind.

 

I highly doubt you burned up any relays. Even if you did, they are all stand alone and easy to test/service. The code reader doesn't do anything that a paperclip can't do. The only real difference is it neatly displays the codes for you rather than requiring you to count engine light flashes or voltage spikes.

Does it start and run if you feather the gas? If so it could just be a stuck/sticking IAC valve. If it doesn't start at all and you definitely have fuel pressure at the rail then you need to check for spark. If you have spark then you will need to pull a plug or two and see if they are wet after cranking to confirm the injectors are firing. If they aren't they either aren't getting a signal, or they are stuck from sitting.

 

The car stays on if I feather the gas, but then it starts smoking a bit. It shakes a bit too much when idling, and the car shuts off if I let go of the gas.

It was also running perfectly fine (minus the engine coolant gauge not working) the day before I goofed this up, so I did do something electrically (but I don't know for sure what happened) when I put the 12v through the wiring for the engine coolant reader. When I did that, I did hear the fuel pump relay (or injector relay) turning on when it shouldn't have been. But what exactly happened, I'm not sure.

Any chance I damaged the PCM, or damaged the PCM and a relay? It would seem possible that the PCM is damaged. If that's the case, I should still be able to replace it.

 

OK, so the relay tester arrived. All 3 of the relays in the engine compartment are fine.

I also took the Idle Air Control Valve off to try it, and the car still kept running way too rich and it kept spitting smells of unburnt fuel out the tailpipes, but it wasn't shutting off anymore.

I think I may have also located the PCM, and it's near the Brake Pedal so it looks like it's relatively easy to get to. Other people online said that's where it's located, and as far as I can tell, it's there.

 

Progress! I was taught to test relays using another relay. Like the horn. If the horn works the relay is good and just swap it with the one you think is bad. Probably not as efficient as a relay tester but then again I didn’t even know that was a thing! There’s a tool for everything!

also I think those IAC valves have to cycle before they start to run right? Also that’s a new guitar in your avatar picture? That thing looks really cool.

 

I figured Relay Testers might be a thing by now, so I went over to Amazon and got this one.

https://www.amazon.com/Sound-Troubl...phy=99593&hvtargid=pla-4583726572072584&psc=1



It works pretty well, just attach it to the battery (negative first, according to the manual) and set the switch to either 4 or 5 prong, plug in your relay, then press the Test button. It'll try cycling the relay 10 times, and if it's fine, it'll show a green light. Simple. I got it with the puller which I didn't really need, but it might be useful on other cars.

As for the IAC Valve, I have no idea. I just pulled the valve altogether to see what would happen, and the car kept running without my holding the throttle. But since it still stank of too rich a mix, that's still not the problem.

On the guitar, I haven't changed my profile pic recently but it's from one of the last few years of department store guitars built in the Chicago area in the 60s. It's a 1966 - 1968 version of the 1965 - 1968 Kay Vanguard II models, this one's a K328 (the most expensive version out of 10 versions made then) but I think it's repainted; they're usually Red Burst like shown below. I don't own the one in my PFP, but I have a parts guitar like it that was in poor shape at purchase. I planed the fingerboard and replaced the frets, but it still needs some parts. I'm not going to bring it back to stock form, but it will have at least one Kay pickup.

Also, for inflation (if counting from 1966,) just multiply by 10, and you roughly have the price these went for. I think part of why these are overlooked are: 1, the quality control was a bit weird back then; 2, lots of people didn't know how to work on their own guitars in the 60s even to just set string height; 3, people often tended to use higher tension strings compared to now and these are already long scale length guitars (they have a longer neck, so the strings already have more tension than a shorter length neck.)

 

Small update, I got the PCM out.

Only... I read that PCM Failure can cause a rich mixture, but I wonder how I would test the PCM if it's not in the car. I still don't know for sure whether the PCM is broken or not.

I also really need to stop worrying about little things here, it's often just nothing at all that's bothering me; illusions and painful nonsense imagined, nothing more. If the problem's there (and it is) then it's repairable somehow.

...

Also, why does NAPA have 12 types of PCMs available for my car, and should I choose one or another?

Edit:
OK, so the PCM Type has a number that I'm not finding anywhere else. Now I'm not sure what to do. It's E8SF-12A650-Y1A, and it's the "Y" part that I'm not seeing anywhere else. It's branded "Ford," and maybe I can get a different one.

Edit 2:
I made a post at the Mercury Forum.

https://www.mercuryforum.com/forum/...-damaged-but-number-ends-y1a-14602/#post30623

Edit 3:
Now I wonder if my ECU has a misprint on it. There are some 1988 Trucks ending in Y1A, after all, but they start with E8TF instead of E8SF:
https://store.allcomputerresources....f-12a650-y1a-pcm-ecm-ecu-engine-computer.html

 

Well, the car's fixed now. I bought and installed a new ECU from Advance Auto Parts that didn't 100% match the stock numbers of my car, but it matches numbers for other Grand Marquis models from 1988 with the same engine. I still need to re-install the lower dashboard panel to cover the ECU, but the car runs now.

Funny how the ECU selling websites strongly say or otherwise suggest on all of their ECUs that I looked at (regardless of their year) that "you'll have to program the ECU to your car VIN." Also, Google A.I. suggested that I'd need "key programming" too. Both of these ideas are nonsense. The ECU that I bought did say it was pre-programmed, but not in those ways. Both the "VIN Programming" and "Key Programming" Features don't exist on this 1990 Mercury Grand Marquis Station Wagon, and I'm not sure when they started, but they're not from this early.

I kept getting delayed since I could not find a match to this exact same ECU type, so I gave up and chose the next best thing. After that, I was a bit worried that the new ECU would break when I installed it. And yes, I did unplug and even remove the battery (for charging) before I installed the new ECU, plus I used gloves, so I did what I could against the chance of static electricity damage.

 

There is no CAN bus network or dozens of other modules to communicate with. It is just receiving information from several sensors and sending output back out based on that. As long as you match up the engine and transmission for the most part you should be in good shape for an ECU of that age. The only thing that might change are pinouts and calibrations from year to year.

 

Man that’s awesome. You’ve got a lot more patience for the computer stuff than I do for sure.

 

Added a 1966 T&C.
Needs love but runs ok.
Maybe 2 new headlights for fog? (HA!)
I will get started with resto work this winter.
It has a 383 with Eddy heads and intake, but Ill put a 440 in it. (1966 was first year for the TNT 440)

 

Sorry, duplicate.