Hi all,

I'm new to the Merc forum, a buddy of mine just bought an '89 with roughly 150,000 miles on it that's in really good shape. Not sure if there's a thread started for these issues or not, but if there is please point me in that direction.

First of all, it takes a really long time to start. I can hear the fuel pump, I put it in accessory and let it sit for a second to pressurize. It's definitely getting fuel, but it turns over and turns over really freely before it actually starts. When it does, the throttle response is really delayed. It has a pretty new alternator and battery just to note... I did new spark plugs, and it seems like all of them are getting some amount of spark. Interestingly, it runs alot rougher when you turn on the fan on the interior, which is why I'm led to believe the rough running is electrical. I haven't touched anything around the distributor or coil, does anyone have advice on what could be going on here? I noticed some of those connectors around the distributor are tough to disconnect, anything I should watch out for there?

The second issue is, when we're able to drive it (it rides absolutely wonderfully), the lights are pretty sporadic. The light switch decides whether you get to have dash lights on with the headlights or not, but sometimes it works great. Hazards work fine, but it refuses to signal right. It signals left at like 3 second intervals. Sometimes both directions are just fine. Thanks to this forum, I found out about lighting control module issues, but I cant find any info on modules for the '89. What kind of issues am I looking at here? I work with electricity for a living, and I'm pretty good with soldering, so I'm up to tackle that thing. Any advice?

I imagine these issues aren't isolated to just me, and I'd love to hear how these can be addressed. When everything on the car works, it's wonderful. All the lights work everywhere, interior, landau bar, cornering lamps, it's quite wonderful. My buddy (and I) fell in love with this thing and all it's problems, it probably would've went to the scrapyard if we didn't pick it up. Anyway, let me know what I should look at here to dive in.

Thank you guys!

 

Just thought I'd update my post, I found a youtube channel called bah53, he's a guy who has an '88 Crown Vic that had all the issues my buddy's Merc is having. He shows how to work on the fuel pressure regulator in a video from August of '17, without removing the intake manifold. He has to fab up a simple tool, but he does it no problem. He also shows how to drop the tank to patch a hole in the line just above the fuel pump before it leaves the tank. That seems to solve his pressure issue. I wonder if you can remove the fuel pump without dropping the tank... Anyway, he also details changing out the fuel filter, which looks real easy, besides brittle white plastic clips that hold the lines in. I think he said new ones come with the filter...

In a video from June of '19, he fixes a seatbelt that wont retract, wiper motors intermittency, and door handle issues.

As for the electrical side, he shows how to replace the headlight switch in a video from October of '19. I'm still not sure if these cars have a lighting control module or not, input would be appreciated. That headlight switch solves alot of headaches, but it doesn't explain why the engine runs worse when the interior fan is on... even with a 1 year old alternator. Again, could be related to the hole in the line by the fuel pump.

Anyway, just thought this resource could help alot of people, it really provided alot of insight for me. If anyone has advice on the weird turn signal issue, that'd be greatly appreciated.
Cheers!