1989 Town Car runs but has no power, can't get it out of back yard. HELP!

[DerekTheGreat]

Gadget, you ever drive one of those 4-6-8's? I wonder what those were like. Also, what about the shitty diesels made from gasoline blocks?

[GM_Guy]

Wasnt the 4100 a clean sheet design? I also seem to remember you had to use specific coolant (even more robust diesel version) for that one as there was a thin wall casting somewhere that coolant impingement caused the cast iron to corrode and leave a hole in the block.

Alex.

[gadget73]

It was a completely new design. It also happened to be a bad one. They used a sealer, which was effectively Barr's Leaks, to make them not vomit coolant. The blocks weren't made in the traditional sense. If you've ever seen an air cooled motor with replaceable jugs, imagine that with a box full of water around it. The cylinders were a Siamese design, so it had 4 cylinder pair units per engine that could be replaced if you wanted to. Those were smushed between the heads and the block with long-ass bolts and surrounded with the cooling jacket.

They did get it better over time. The 4500 and 4900 were based on the 4100, and were not quite so problematic. They also abandoned the engine family entirely for the Northstar motor after about 10 years. It sounds neat on paper, but in practice it just wasn't that durable. The boring old 307 wasn't half so fancy, and it was an underpowered smogger mess but it actually ran reliably.

Never driven an 8-6-4 or the 350 diesel. I'd like to. I've driven a Mark VII turbo diesel, and it was not the underpowered piece of crap it was made out to be. It wasn't a hot rod by any stretch but it was completely tolerable in terms of performance. Certainly no worse than a stock box, and it got way better fuel economy.

[DerekTheGreat]

Northstars seem to have quite the reputation for chewing up head gaskets. I'd avoid them. I did like the 90's eldorados though. "Underpowered smogger mess." I've peered under the hood of things equipped with that motor and I agree. I'll drive my Fury all summer long but I'm against carbs in an everyday vehicle. Can't believe that Cadillac kept those things around until '89. I've never known a carb'd car to cold start without pumping the gas or run reliably without setting the choke at first. Would hate to have to do that everyday. Don't mind it one bit in the Fury because of it being a hobby car and all though. I saw one of those Mark VII's for sale about a year ago. Was in great shape but that engine just looked out of place to me. It was a BMW engine right?

[gadget73]

GM never went EFI on the 307, and by the late 80s it was the only BOP engine made. GM did some stupid things. The Caprice wagons got an Olds 307. The Caprice sedan in the same year got a TBI Chevy 305. My boss has an 89 of each. Completely different dashboard and interior too. Exactly why they didn't just shoot that thing and put TBI 305's and 350's in everything baffles me.


The Mark VII diesel was the same one used in a BMW. It wasn't a BMW motor proper, it was a Stehyr 2.4 I6 bolted to a ZF transmission. Apparently they had head cracking problems though, so getting a good one now can be dicey. They were a strange mess under the hood. German motor with US accessories and transition electrical connectors between the two. Finding people to work on that is probably difficult. Ford dealers didn't know what to do with it, and BMW places probably wanted nothing to do with it. The Mark VII was always kind of hard to get service for. The ABS and air suspension confused people 20 years ago. You may as well forget about it now. If you want one of those, you best become a diesel mechanic.

[DerekTheGreat]

The wagons got the turd 307? Wow. My buddy bought an '89 Caprice Brougham with the LO3 305. Previous owner blew it up but once we swapped the engine with another one it was great. Funky interior though, liked the seats and doors but the dash was just goofy and I was a bit disappointed that GM was still using flood lighting to illuminate the instruments. My '69 Fury has that. GM does indeed do weird things. Cadillac is a premium name, yet was the last to get the "advanced" powertrains. Ford was weird too. Why was a Town Car so basic? Was it like a legacy thing? Why was ABS, four wheel air suspension & four wheel disc brakes and full digital instrumentation available on the Continentals & Mark VII's yet not on a Town Car? Had to wait until 1990 but that's also the year of the body style change.. Illuminated door controls would've been a great feature too.

[DerekTheGreat]

I know you said you were careful to put the distributor back in exactly as it came out, but it wouldn't hurt to double-check your work on that end.
From what I've read here, it could be possible that the distributor housing is correctly placed in the hole, but the shaft could have turned when it was out juuuust enough to have been put back in so that it's off a tooth where the gear meshes with the camshaft. From the symptoms you're describing, my guess would be retarded a tooth, meaning it will still start and run, but really badly with zero power.
If it were me, I'd bring the No. 1 cylinder to TDC and remove/replace the distributor in the correct position using a service manual, and while I was at it I would double-check the plugs wires.
I used to mix that stuff up a lot one time until I learned the tricks for getting it all right the first time. I still get nervous when a distributor comes out lol.... That being said, the fuel pressure test isn't a bad idea either. Could be a coincidence that started acting up when you were at the other stuff there.

I owe you, gadget and anyone else who advised me to check the timing an apology. The distributor did just that. I swaped the coil, no change, some change was noticed by the different TFI module but when my buddy and I noticed the rotor was in a different position after putting it back in we played around and found that the timing was retarded by a tooth. Car seems to run great again, throttle response is there, starts upssuper easy now (perhaps that TFI module had something to do with that??) And now I can't wait to test drive it tomorrow. She's just gotta get insurance put back on it.

Thanks again for all of your help and suggestions! You guys know your stuff and glad you guys took the time to stop and comment.

[nfldfordltd]

Glad you got it sorted out. Hope you get kisses from the missus for a job well done.
Happy motoring!

[DerekTheGreat]

Hah I should've just told her that the TFI module fixed it but I admitted that I screwed up the timing back when we tried to change out the thermostat. All I got was, "Great, glad you figured it out and so now we don't have to take it to the shop to fix your mistake!" I think I learned something yesterday...

[miamibob]

Relationships are like being in the military - NEVER ADMIT SHIT!!! LOL

[gadget73]

LOL

all's well that ends well. I can't help but think it would have ended more poorly if you had taken it to a shop and they told her why it was broken. Plus, money.

[DerekTheGreat]

Haha no doubt, I'd have had to pay for it (rightfully so) and then I'd never hear the end of it and shed probably never let me touch her car again.