Not another what C4 to get but....
07-23-2018, 04:52 PM
#1
Not another what C4 to get but....
Hello all!
New here from Arkansas and wanted to ask a question regarding C4 Corvettes. I am thinking about buying my first ever Corvette and the research I have done so far tells me that a 1985 is the one to get IF you want to avoid the crossfire engine, air bags AND anti theft devices that may be an electrical issue with regard to reliability. I would like something a little easier to work on and the 1985 is the one recommended. Is this true, what are your thoughts about easiest to work on and reliability issues.
Thank you in advance.
Tom
New here from Arkansas and wanted to ask a question regarding C4 Corvettes. I am thinking about buying my first ever Corvette and the research I have done so far tells me that a 1985 is the one to get IF you want to avoid the crossfire engine, air bags AND anti theft devices that may be an electrical issue with regard to reliability. I would like something a little easier to work on and the 1985 is the one recommended. Is this true, what are your thoughts about easiest to work on and reliability issues.
Thank you in advance.
Tom
07-23-2018, 05:17 PM
#2
Every year has its issues. The 85 is no different.
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TCBronson (07-24-2018)
07-23-2018, 05:21 PM
#3
Hello all!
New here from Arkansas and wanted to ask a question regarding C4 Corvettes. I am thinking about buying my first ever Corvette and the research I have done so far tells me that a 1985 is the one to get IF you want to avoid the crossfire engine, air bags AND anti theft devices that may be an electrical issue with regard to reliability. I would like something a little easier to work on and the 1985 is the one recommended. Is this true, what are your thoughts about easiest to work on and reliability issues.
Thank you in advance.
Tom
New here from Arkansas and wanted to ask a question regarding C4 Corvettes. I am thinking about buying my first ever Corvette and the research I have done so far tells me that a 1985 is the one to get IF you want to avoid the crossfire engine, air bags AND anti theft devices that may be an electrical issue with regard to reliability. I would like something a little easier to work on and the 1985 is the one recommended. Is this true, what are your thoughts about easiest to work on and reliability issues.
Thank you in advance.
Tom
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TCBronson (07-24-2018)
07-23-2018, 08:36 PM
#4
Advanced
My approach before settling on my ’94 was deciding what features I wanted. I decided I didn’t want the Atari dash models so for me the early models were out. I also wanted a level of technology I was comfortable with. I wanted ABS and air bags and the newer R-134 refrigerant. I bought a copy of the Standard Catalog of Corvette by John Gunnell that covered up to 2005 (before I settled on a C4 over a C5) that helped me narrow the field before checking out any in person.
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TCBronson (07-24-2018)
07-23-2018, 09:29 PM
#5
Le Mans Master
There's probably less to go bad on a crossfire but that's a discussion for another day as you've ruled them out. The only real issues with 85s are the lack of support for the ecm and the damn burnoff relays if equipped... my l98 knowledge is very limited but those cause all sorts of crap. Also factory injectors don't fare well with ethanol but most should be replaced by now. The 85 is an 84 with tpi as far as the block is concerned....
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TCBronson (07-24-2018)
07-23-2018, 09:38 PM
#6
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If you plan to do all the maintenance yourself, then the 1985 might be a good choice.
If you plan to have a mechanic do the tough stuff, then an OBD II car could be the wiser move.
If you plan to have a mechanic do the tough stuff, then an OBD II car could be the wiser move.
Last edited by rocco16; 07-23-2018 at 09:39 PM.
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TCBronson (07-24-2018)
07-23-2018, 10:12 PM
#7
Race Director
Post #4 is great advise, I agree with those that have said the '85 has the least amount of electronics so it is about the easiest DIY of the TPI C4s.
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TCBronson (07-24-2018)
07-23-2018, 10:52 PM
#8
Tech Contributor
I have an 85, and one thing to be aware of is the one year only "Burnoff module" and the 870 ECM.
The burnoff module for the MAF is hard to find, and when it goes bad the MAF doesn't function, and the car will run like ***. Ask me how I know. I ditched the 85's ECM setup and went with a FAST setup. Of all the other things though, no ABS, air bags, etc its pretty nice to work on. I do all my own stuff.
The burnoff module for the MAF is hard to find, and when it goes bad the MAF doesn't function, and the car will run like ***. Ask me how I know. I ditched the 85's ECM setup and went with a FAST setup. Of all the other things though, no ABS, air bags, etc its pretty nice to work on. I do all my own stuff.
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TCBronson (07-24-2018)
07-24-2018, 06:21 AM
#9
Team Owner
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I suggest you pick up a copy of the "Corvette Black Book" as it spends 2pp on each year of Corvette describing new features and options list.
For years '84-'89 there was no air bags and there was a tilt/tele. steering wheel and the "star-wars" dash. The 'mid-year '86 came with the Al heads. The 17" wheels came with some options in '88, standard in '89-'91.
For years '84-'89 there was no air bags and there was a tilt/tele. steering wheel and the "star-wars" dash. The 'mid-year '86 came with the Al heads. The 17" wheels came with some options in '88, standard in '89-'91.
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TCBronson (07-24-2018)
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TCBronson (07-24-2018)
07-24-2018, 03:39 PM
#11
Team Owner
Pro Mechanic
I'd say the "difficulty" of the opti is offset by the difficulty of the L98 water pump. And intake.
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TCBronson (07-24-2018)
07-24-2018, 04:02 PM
#12
Melting Slicks
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I don't know that any of them are "bad" Even the crossfire. There's guys who like them and if you aren't racing it, the crossfire almost has a throwback, "kitchy cool" kind of thing going on now, because they're so unique to the period.
But everyone has their favorites and I like the 85. I think it's perfect. I like the look of the early C4's. As you have noted, I like the fact that it has just enough tech to be useful, but not enough to turn into a maintenance hassle. I love the blackout, video game style, dash! It's like firing up a fighter jet.
If there's a truly notable drawback to the year that I am aware of, it is the ECM. It can still be tuned, but it's a weirdo unit that utilizes a burnoff module rather than separate relays. This can be updated and it is relatively easy to do. If you want to mod it further, you can even go all the way to EFI Connection's kits and coil on cylinder. So, it's not a deal breaker, but it is something different about the 85 that is worth noting.
Good luck!
But everyone has their favorites and I like the 85. I think it's perfect. I like the look of the early C4's. As you have noted, I like the fact that it has just enough tech to be useful, but not enough to turn into a maintenance hassle. I love the blackout, video game style, dash! It's like firing up a fighter jet.
If there's a truly notable drawback to the year that I am aware of, it is the ECM. It can still be tuned, but it's a weirdo unit that utilizes a burnoff module rather than separate relays. This can be updated and it is relatively easy to do. If you want to mod it further, you can even go all the way to EFI Connection's kits and coil on cylinder. So, it's not a deal breaker, but it is something different about the 85 that is worth noting.
Good luck!
Last edited by confab; 07-24-2018 at 07:55 PM.
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TCBronson (07-24-2018)
07-24-2018, 06:36 PM
#14
Team Owner
Always try to find the best Corvette for the money you have to spend. But keep some money available for maintenance, repairs, or upgrades. Consider what transmission works best for you; 84-88 manual transmissions was the Doug Nash "4+3". It was a BW Super T-10 4-speed with an overdrive. When they work, they are a good trans. Starting in '89 thru '96, Corvettes used a ZF 6-speed. The auto trans cars used a 700R4 (4L60) and went to an electronic version in '94. Wheel and tire sizes are another thing you may want to consider. The 84-88 cars used a 16" wheel and 255/50-16 tire.. A 17" wheel tire was optional in '88 and became standard in '89.
I would suggest building your budget then go drive a number of C4's. Don't get hooked on the first one!! There are too many nice C4's floating around at good prices and condition.
I would suggest building your budget then go drive a number of C4's. Don't get hooked on the first one!! There are too many nice C4's floating around at good prices and condition.
07-25-2018, 05:53 AM
#15
Le Mans Master
Pick the year you want and grab a set of Field Service Manuals off of ebay for that year. While I agree some years are easier then others, for the most part once you have the FSM's fixing any year a lot easier, the FSM's are very good with getting though just about any problem with minimal hair pulling. Each C4 got better each year implementing previous years fixes and I'm a fan of the saying, "buy the latest model year you can afford",
07-25-2018, 04:14 PM
#16
Intermediate
85 with 4+3
Until you have to deal with the water pump or the optispark distributor, they are about the same degree of difficulty. I can get the distributor out of my L98 in less than 5 minutes including opening the hood. Can you get the opti off your LT in under an hour?
I've worked on C4's of almost every year. The OP has the correct assumption that the 85 is the simplest to work on, in that it has the least content. There's a lot of things in later years that the 85 doesn't have. VATS, C68 climate control, ABS brakes, Supplemental Inflate System, CCM and its associated systems, opti-spark, FX3 suspensions, RKE and its fussy key fobs, head-pipe cat converters, ASR, remote-head radio systems (90-up), and probably a few more I didn't think of. 85's are "easier" because they don't have these things. The top IP pad can be removed in an 84-89 in about 10 minutes. In a 90-96 about an hour if you've done it a few times.
A couple of detriments for the 85: Automatic transmissions are the early 27-spline 700R4. The automatic gets better in mid 1988 (30-spline). I would presume most 85's still running have had a later transmission substituted when the original POS failed. The 4+3 received several updates in mid-March 1985. About VIN 24,500. The 4+3 can still be problematic, but one earlier than this that hasn't had the upgrades is a time-bomb.
For a first Corvette for a DIY'r, the 85 is about as simple and "easiest" as any of the C4's.. They also made almost 40,000 of them, so they are plentiful in every condition from junk to garage queens. Look at and drive as many C4 of different years as you can, and you will know when you've found "the one".
I wouldn't bee too concerned with VATS. (The anti-theft). It is easily dealt with or bypassed. Optispark replacements, C68 maladies, and "SYS Error" (90-up CCM error indicator) not so much.
I've worked on C4's of almost every year. The OP has the correct assumption that the 85 is the simplest to work on, in that it has the least content. There's a lot of things in later years that the 85 doesn't have. VATS, C68 climate control, ABS brakes, Supplemental Inflate System, CCM and its associated systems, opti-spark, FX3 suspensions, RKE and its fussy key fobs, head-pipe cat converters, ASR, remote-head radio systems (90-up), and probably a few more I didn't think of. 85's are "easier" because they don't have these things. The top IP pad can be removed in an 84-89 in about 10 minutes. In a 90-96 about an hour if you've done it a few times.
A couple of detriments for the 85: Automatic transmissions are the early 27-spline 700R4. The automatic gets better in mid 1988 (30-spline). I would presume most 85's still running have had a later transmission substituted when the original POS failed. The 4+3 received several updates in mid-March 1985. About VIN 24,500. The 4+3 can still be problematic, but one earlier than this that hasn't had the upgrades is a time-bomb.
For a first Corvette for a DIY'r, the 85 is about as simple and "easiest" as any of the C4's.. They also made almost 40,000 of them, so they are plentiful in every condition from junk to garage queens. Look at and drive as many C4 of different years as you can, and you will know when you've found "the one".
I wouldn't bee too concerned with VATS. (The anti-theft). It is easily dealt with or bypassed. Optispark replacements, C68 maladies, and "SYS Error" (90-up CCM error indicator) not so much.
My 85 has 4+3 with VIN 300XX , so most likely it has the upgraded 4+3 ??
07-25-2018, 11:42 PM
#17
I have seen guys chasing their tails in circles, talking themselves into the rarest color, shifter, engine and so on, and I guess I can understand if you only have one space in the garage and one pass from the spouse to make a purchase.....but the truth is, c4s can be had cheap, and they are all fun...
07-26-2018, 07:27 AM
#18
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St. Jude Donor '05
x2
Its an old car, even brand new ones break down. The problems you read about with these they had new-defects
Always buy on condition, not mileage or some "rare" whatever-ignore shiny paint and see what the car really is.
One thing to like is manual ac, seats, no abs, BCM stuff that breaks or drive$ you up the wall. Some like gadgets, others like to keep it simple.
Its an old car, even brand new ones break down. The problems you read about with these they had new-defects
Always buy on condition, not mileage or some "rare" whatever-ignore shiny paint and see what the car really is.
One thing to like is manual ac, seats, no abs, BCM stuff that breaks or drive$ you up the wall. Some like gadgets, others like to keep it simple.
Last edited by cv67; 07-26-2018 at 07:28 AM.
07-26-2018, 02:49 PM
#19
good point Tom. my understanding is that there is a touch of "ticking time bomb" with optis and i dont think that can be said about the tpi intake or dizzy. perhaps the icm.
anyway, OP, my 2c is the same as others. they are all going to need work.
i happen to have restored an 85, 86, and an 87.
The 85 was infact the simplist. Abs was fried in the 86. Digital hvac (c68) was fried in the 87.
85 has stronger pistons (i read that somewhere) if u plan on going apesheet with a ho build.
one thing i came to realize about the 85 vs all other tpis is that it is not scannable in any real helpful way for the purposes of diagnoses. it will give you codes, same as any other, and you can scan it, but its not going to give you the same real time data readout as the 86+ will.
due to this forum and its vast resource bank of fellow tpi owners, the non-useful scanning of the 85 is by and large not an issue.
just pointing it out incase u were planning on getting into aldl scanning with it.
cheers.