Hello!

I'm a new member and just bought my 'new', stock, automatic, 1985 7 days ago with 108,000 old man miles. I flushed the brake system. I'm adding new plugs, wires, cap/rotor this weekend as well as coolant flush and fuel filter. I have ordered a fan switch and thermostat from CC for cooler running. The trans will get a full flush the following weekend. I don't have a FSM yet but hope to get all the grounds leaned up ASAP. The car was driven 17,000 miles in the last 15 years but was kept in a heated garrage. After cleaning a sticky TB, it runs and drives great!

I saw a list on corvsport of common issues with the 1985 which included failing oil pressure switch; fuel pump relay; ignition module; TPS; MAF sensor; PROM

I want to use the car for trips up to the MN woods and was wondering what the consenus was on replacing some of these parts before failure? If the car lasted 108k miles could one assume that, 1: faulty parts have already been replaced, or 2: the parts lasted this long and should be good?

What about the ancient fuel pump?

Thanks for the help!

 

That too would be a good item to replace, IMO.
My prior '88 had 92k on the clock and it failed, leaving me waiting for a flat-bed.

I would suggest you put some miles on the car before venturing very far into the wilderness.

 

When I acquired the 93 - wound up replacing the entire fuel system - from fuel pump to injectors and everything between being fuel related because the 20 year old fuel filter was still there... undercoating overspray. Was a clear indicator how the car was mechanically maintained. Didn't want to rely on rubber components that old with the corrosive properties of the ethanol gas presently. That is why maintenance records are highly preferred.

 

Fuel pump is a easy 30-45 minute replacement if you have never done one before. Get yourself some form of manual....even if it a a Haynes or similar. It will keep you out of trouble for the basic things.

The best way to change out the coolant is to remove the plug in the block on the driver's side and the knock sensor on the passenger's side. There may be a rust build up over these on the inside of the block. Just poke a screwdriver thru the rust.....be prepared for a RUSH of coolant.

Check behind the radiator for debris build up. Take the top off that is over the radiator and clean this area out down low. These cars are bottom feeders and pickup all kinds of things that get stuck in this area.

Be aware that the automatic trans are good for between 100,000 and 120,000 miles approx. before the need to be rebuilt.


PM Sent to you.

 

how's the starter? if you suspect it's on the original starter, definitely replace it. When I bought my 96 LT1 with 56k miles, the starter was the first thing to go on me, leaving me stranded. On the LT1, the starter was very easy to access and replace (i think it took me longer to jack the car up). I can't speak to how easy it'll be on the 85, but probably not too different.

 

My 85 had 73,000 on it. I have been replacing just the make sense stuff, plugs, wires, cap, rotor, coil, u-joints, wheels bearings, bushings, shocks. No fails so far. If it can wear out, it will.

 

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might want to add a thermostat to your shopping.

 

You are off to a great start. Just some ideas for a couple of weeks of fun weekend projects.

I'd finish up by doing the full fuel system including fuel filter, new fuel pump, Fuel pressure regulator, fuel rail and inlet o-rings, and maybe injectors if they have not already been replaced. Even at 16K miles, I has a lazy/dead injector on #7 cylinder so miles has nothing to do with it. just did this job last weekend, some part numbers:

Rail O-ring kit:
GP Sorenson 800-9211 or bwd 274773 (usually in stock at autozone)
Fuel inlet orings BWD 21720
Regulator diaphram GP Sorenson 21720 (also in stock at autozone)
Good idea to replace the EGR valve while the Plenum is off.

I used the updated "OEM" Delphi injectors and they are indeed spot on for the factory tune on my '89. BLM's are dead on.

As was mentioned, the fuel pump is real easy @ 30-40 minutes, just make sure you have a new gasket and O rings for the perimeter bolts prior to doing this job. Ask me how I know

Rear end diff fluid change is a piece of cake. Dropping the pan on the auto, replacing the filter, and flushing out the old fluid front the front of the car is a 2-3 hour job taking your time.

Other than that, you might want to do factory service stuff like setting up the base idle, TPS voltage set, and IAC reset etc. 1 hour

Also might not be a bad idea to check all of the vacuum lines and plenum for leaks. I like to use the cigar smoke technique. Just seal up the front of the throttle body and blow smoke into the plenum via the brake or PCV ports. If you have a vacuum leak, this is a sure way to find it! 1 hour

Just a word of caution on removing the thermostat. It is common for the 3/8 bolts to be rust welded on the manifold. Don't force the bolts out. If you manage to get them out a few turns and they get stiff, STOP. Use PBblaster and spray the threads and let it sit for a few hours and then consider just screwing them back in and leave well enough alone. If you proceed, slowly turn the bolts in and out to loosen up the rust. If you snap a one of these bolts, you'll curse the heavens, trust me on this one.

 

I must be Lucky then...My 91 Vettes 700R4 has 143k on it and performs Great!...

I've flushed the fluid twice since 70k (7 quarts of Mobil 1 Full Synthetic trans fluid added each time) and installed a heatsink trans cooler at around 90k.





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joining your preventative maintenance thread before i start my own work on 87 auto coupe w/ 185,000 klm. (just over 100k miles). no issues on it yet but i don't want to get stranded. it'll cost me no more money to fix things early, in fact with todays inflation it'll save me money to do it now rather than later!

Anybody in Canada know where the best place, online of offline, is to get c4 parts at the best price?https://www.corvetteforum.com/forums.../Cdnsmilie.gif

 

welcome to the forum....most of us are crazy but there are a bunch of guys who know what theyre doing...lots of guys who have 85's here

don't screw with the maf- they're expensive...your chip is good...the hperchips do not work...your vette will throw a code if they become a problem....the fuel pump is another issure...convette central has some nice stainless pumps and sending units....easy installation....get a fsm GM....at e-bay......you'll absolutely need it....post some pics....guys get in the habit of throwing parts at the engine...tps is fine....you'll know if it's not working.....lots of threads here to due regular maint....timing/ tps/ minimum idle adjustments.......have fun.....don't forget to write...

 

Summarize; a 26year old car with a 108K on the clock with clean fluids/filters.

Those are the most common, yes. You can go about and replace the listed items except the PROM which doesn't fail. And the MAF which is too expensive until it fails. (FWIW Don't try cleaning it or using an oiled air filter)

A few very important components your overlooking. Tires, shocks, air filter and diff fluid. And battery. Keep your battery topped with a battery tender, or you'll be replacing the alternator as well. Check all the grounds in the engine compartment especially those around the battery.

I carry a battery cable cutter, fire extinguisher within easy reach. A FP and MAF burn-off relay, serpentine belt, an ignition module and spare t-stat. All of which can fit in the passenger side rear storage compartment.

Once your car starts to get used, you'll begin to find oil leaks and other problems that will appear. So that FSM is a must have to trouble shoot and assist with repairs. Parts can be found on Rock Auto, eaby and of course the vendors here.

 

I just got my first Vette (88 verte) about 2 months ago, maybe 3, and am still in the learning process. I am 68 yrs. old now and had to wait that long to acquire a Vette but I do enjoy it. Get and FSM and if you are like me, it will take some getting used to. They are for more skilled mechanics or folks used to Vettes than I presently am. I am used to the old carb cars, mostly from the 30's to the 60's. Don't be afraid to ask questions as this forum has some great guys on here that are very capable and willing to help. I would recommend putting some "Wetter Water" into your cooling system though. I live in Az and I believe it does help. Good luck with your toy and welcome to the forum.
Tommy

 

been there - done that....

 

What?

 

"been there - done that..." well, what i was trying to get across, is over the last 20 years or so, I've probably bought and installed 95% of all those parts shown -- and then some. i figure if you own your C4 long enough, you'll replace or repair just about everything at least once. seems there no end to it, but still having fun!!!

BTW, love the avatar shirt!

 

I will join the '85 chorus. The PO of my car spent $11K on making it look purty and left me with all the mechanical restoration. I DD my car so I am a firm believer in fix it when it breaks (and damn quick cuz I gotta get back to work!). That being said, I have replaced all u joints and rear wheel bearings, master cylinder, clutch hydraulics, headlight motor, window motor (upgraded to newer style) water pump on and on. I understand your concern about taking it into the woods but you can only do so much, even a new part can fail on ya. Just make sure you change all the fluids, belt and hoses, normal road trip things. Check the date on your tires. Even if they have tread and they are 7+ years old I would think about replacement if the handling isnt spot on or you see cracking.

Good luck with it!

AND..............