mopar master
Well-Known Member
Hey y'all. What are some good all around upgrades for the 89 fifth avenue? And anything that general gos bad that needs to be fixed before hand.
Upgrades
- Thread starter mopar master
- Start date
SonOfaTomP
Well-Known Member
keep an eye out for that spark control computer on the air cleaner. does your Fifth in general run well now? don't worry about it. but if it begins stalling, shaking, making weird noises. lean burn delete kit might do wonders. did wonders for my Gran Fury. this involves a new carb, distributor, and ignition module
AMC Diplomat
Well-Known Member
I'm still running the lean burn because it's an engine that'll get yanked anyways. So it's status quo until the timing chain goes.
My diplomat has rolled its odometer at least twice. It was also previously owned by idiots. In the short time that I've had it, I've replaced the choke thermostat, choke pull off, fuel pump, pcv and breather, air filter, air intake hose, battery cables, starter, alternator, lean burn computer (because I found a deal), spark plugs, wires, ignition coil, neutral safety switch, rewired the taillights, leafsprings, changed the diff oil, put a whole new interior in and changed the front header panel. And I'm sure I've forgotten a bunch of other stuff and there's more in the planning phases, like 8 1/4 diff with sure grip and rear sway bar
What made the biggest improvements for the engine were the fuel pump, new coil, plugs and wires, the neutral safety, choke thermostat and choke pull off and the starter. Car starts every time and I really noticed a difference after fixing the vacuum choke pull off.
For driveability, look into replacing the leaf springs if they're original. I picked up inches in ride height and it made a huge difference in drive quality.
Oh yeah, brake hoses, if they're original, replace them.
Oh! The stereo! You can use any Chrysler stereo I think up until 2002 as long as it's the same size. I picked up a near new one for $9 on ebay.
Get a parts book and get a factory service manual for your year. Don't spend a lot of money on a parts book either. Cheapest one I have a paid $8, most expensive was $30. People want stupid money for those 80s parts books when the reality is no one wants them but us.
So tl;dr: choke, stereo, leaf springs, brake hoses, factory service manual, parts book
My diplomat has rolled its odometer at least twice. It was also previously owned by idiots. In the short time that I've had it, I've replaced the choke thermostat, choke pull off, fuel pump, pcv and breather, air filter, air intake hose, battery cables, starter, alternator, lean burn computer (because I found a deal), spark plugs, wires, ignition coil, neutral safety switch, rewired the taillights, leafsprings, changed the diff oil, put a whole new interior in and changed the front header panel. And I'm sure I've forgotten a bunch of other stuff and there's more in the planning phases, like 8 1/4 diff with sure grip and rear sway bar
What made the biggest improvements for the engine were the fuel pump, new coil, plugs and wires, the neutral safety, choke thermostat and choke pull off and the starter. Car starts every time and I really noticed a difference after fixing the vacuum choke pull off.
For driveability, look into replacing the leaf springs if they're original. I picked up inches in ride height and it made a huge difference in drive quality.
Oh yeah, brake hoses, if they're original, replace them.
Oh! The stereo! You can use any Chrysler stereo I think up until 2002 as long as it's the same size. I picked up a near new one for $9 on ebay.
Get a parts book and get a factory service manual for your year. Don't spend a lot of money on a parts book either. Cheapest one I have a paid $8, most expensive was $30. People want stupid money for those 80s parts books when the reality is no one wants them but us.
So tl;dr: choke, stereo, leaf springs, brake hoses, factory service manual, parts book
Mikes5thAve
Well-Known Member
Upgrades all depend on what you want to do to it. Does it have any running problems? What goes bad is typical of any car. Shocks, springs, brake hoses, brake linings, steering and front end components.. all the stuff that makes it no safe to drive if worn out. But there's no point to replacing that stuff unless it's needed.
Plugs cap and rotor not a bad idea if you don't know when they were done last.
Service manual is good to have. Factory one has info you cant find anywhere else, especially wiring, and for normal repair stuff this might be the only case id say to get a Haynes one because it was largely based on a Diplomat so the info in is good and its straight to the point and easier to use then the factory ones. Parts book nice to have but not totally necessary if your car is in good shape and you're only problem is replacing maintenence type parts.
Plugs cap and rotor not a bad idea if you don't know when they were done last.
Service manual is good to have. Factory one has info you cant find anywhere else, especially wiring, and for normal repair stuff this might be the only case id say to get a Haynes one because it was largely based on a Diplomat so the info in is good and its straight to the point and easier to use then the factory ones. Parts book nice to have but not totally necessary if your car is in good shape and you're only problem is replacing maintenence type parts.
Last edited:
What exactly do you want out of the car and your driving experience?
There’s plenty that can be done to them and we all have our cars put together differently; but, the people on here will be able to provide better advice knowing more about what you’re looking for from your car.
There’s plenty that can be done to them and we all have our cars put together differently; but, the people on here will be able to provide better advice knowing more about what you’re looking for from your car.
mopar master
Well-Known Member
Thanks y'all. Yeah it runs like crap at the moment. I'm pretty sure it's the lean burn. Everything's on the car and it's in really good shape for the year. Not perfect but good. I would love it to be kinda a sleeperish daily. Nothing crazy like a hellcat swap. But something just reliable and fun to drive. I love the 318. Id love to build it a little. I know ppl say swap it but I just love them.
Mikes5thAve
Well-Known Member
It's not lean burn by that point but at least everyone knows what thst means lol
Since you're looking at a bit of performance and ideally you'd change the carb anyway nows the time to go 4 barrel while you're at it. Edelbrock performer intake will let you keep air-conditioning if you want it along with egr etc. I've always run normal factory ignition on my cars with vacuum distributor.
Since you're looking at a bit of performance and ideally you'd change the carb anyway nows the time to go 4 barrel while you're at it. Edelbrock performer intake will let you keep air-conditioning if you want it along with egr etc. I've always run normal factory ignition on my cars with vacuum distributor.
mopar master
Well-Known Member
Are you saying its not the lean burn
Lean burn could be working perfectly and is trying to compensate for ignition/fuel/mechanical issue/s and that’s what’s actually causing the poor running issue, for example.
Mikes5thAve
Well-Known Member
They system itself isn't leanburn.
The running problem could be any number of things from the computer itself to the carb or a sensor or even just the timing not set right. Usually it's not the computer.
It could be something simple but might not be worth spending much time on if you're after performance.
mopar master
Well-Known Member
Oh ok. I got it. If we don't get snowed in I'll try and hunt the problem down this weekend
mopar master
Well-Known Member
This is probably a stupid question but would how much gas you have in the tank affect how it runs. Might be just a coincidence but if it has over half a tank it seems to run perfect
AMC Diplomat
Well-Known Member
My best guess would be a bad pick up in on the sending unit in the tank. Maybe the bottom is clogged and there's enough holes in the top for fuel to get in. Or the pump is bad. These are guesses from a fool on the internet. Proceed with caution
Could have a pinhole leak in the in tank fuel sending unit. Like straw with a hole. Drinks fine when holes submerged in fluid but, once the hole gets exposed to air, gets hard to drink. Just an example.
mopar master
Well-Known Member
Thanks. Those are Alot better guesses than I would have guessed.
mopar master
Well-Known Member
So anyone have cup holders. Most luxurious car Chrysler had in the 80s and no cup holders
AMC Diplomat
Well-Known Member
Justwondering
Well-Known Member
mopar master ...
We went with seat gap cup holders... just be aware you have the seat belt connectors there.
Something like these ... lots of options-- but not as fancy as the console.
JW
We went with seat gap cup holders... just be aware you have the seat belt connectors there.
Something like these ... lots of options-- but not as fancy as the console.
JW
MoparDan
Well-Known Member
My '85 had a BAD stalling issue, it turned out to be the carburetor needed to be rebuilt and then retuned multiple times, because these are very complex carbs because they're built to run with the computer (guy who rebuilt it said it's the one of the worst carburetors ever put in an American car)
Not yet. I swapped 40/40 seats into my car and will be fabricating a center console out of plate aluminum in summer.
