C4 ZR-1

If I remember right..(and that's a big if) the early cars had timing chain problems at cold start. I can't remember if it effected all cars but I do remember a campaign on them.

 

And a current owner. I've daily driven my '90 for the last 10 months and it's an amazing machine, radically different from a Ferrari. The engine absolutely dominates the experience, but the handling is actually very good - quicker turn in than my 308. I autocrossed it this past weekend and after I got used to a little shake, rattle n' roll, the grip and power were just phenomenal.

The ZR-1 forum is a great resource. Lots of great people there, much like fchat, and tons of detailed technical knowledge.

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There are lots of small detail differences through the years, 90-95, but all the major things are really the same. Chiefly the engine remained largely the same, just with a couple changes through the run. There was an early change from 2-bolt to 4-bolt mains, and the 90 had twin throttle cables to the later cars single cable. But otherwise it's a beautifully made 4-cam, 32 valve 5.7l V8 engine with a serious Jekyll and Hyde mentality. There are 16 injectors, 3 throttle plates and two distinctly different intake paths controlled by vacuum and throttle position. It's a holy crap engine. The primary throttle plate is about the size of a quarter, and runs on the 8 primary injectors, good for about 200hp. Then the transition to the secondary throttles (BIG), and the other 8 injectors kick in, and you get a wallop in the back of your head that is just fantastic.

All of them rattle at startup and shutdown, very typical. But it should quiet down after just a few seconds. The ZF 6-speed box is a beast, but shifts should be tight and solid, very little play in the shifter. The first 3 gears are straight cut, so expect a whine and don't be afraid of it. The throwout bearing is also noisy and designed that way, apparently something to handle the power transition.

Turn the key on but don't start it yet. You should hear the vacuum pump kick in, located under the right headlight. That keeps the vacuum system primed and makes the transition from primary to secondary throttle system nice and smooth. While running you can hear it cycle on and off, about every minute or so. If it's a lot quicker than that, expect a vacuum leak.

Feel free to contact me, I've learned a lot about these cars in the last year and still learning more. The guys on zr1net are really great too and are probably familiar with the exact car you're going to see.

 

With under 30k, I wouldn't expect much for service records. It's an American car and most people just weren't as fanatical about service as we are today. My car was stored for 15 years, didn't even get started in that time. Because of that, it's got new injectors, lines, fuel filters, O2 sensors, water pump and hoses, belt tensioner, and a few other things. But the LT5 is known to be nearly bulletproof and can run up huge mileages, so as long as it's been driven fairly regularly it should be ok.

 

I agree with the above. Bullet proof engines. Check the vacuum line at the map sensor at the center rear of the intake. The rubber fittings can crack and a cel will show and it will run poorly. I serviced these when I was at GM. Some had front crank seal oil leaks and it's an engine out replacement. Fuel pumps and injectors were not E85 compatible back then so a fuel pressure check should be done. The drive train is very tough and the rest is off the shelf C4, anvil like reliable. Use a PF970C AC oil filter when changing oil. The chains do rattle and that is normal on start up and shut down. Most corvette owner don't loose sleep over service records like F car guys do. The cars just don't break. As Jay Leno once said... It's a Chevy and you can fix it with a hammer.
Good luck.

 

I am an original owner of a 1991 ZR-1 and enthusiastically second the comments in this tread. It's a heckuva car. One problem not mentioned, though, is delamination of the windshield. It either happens or doesn't, and isn't related to any external condition (exposure to sun, etc.). There is no cure, and no replacement original windshields AFAIK. A standard C4 glass will fit but lacks the small rectangular clear porthole to the right of the steering wheel that only the ZR-1 windshields have.

A great resource in the Maryland area is Tony's Corvette Shop in Gaithersburg. One of the best shops in the country. Have Tony do a professional PPI. <tonyscorvetteshop.com> 301-987-0565

If the car stays in the Maryland area, get in touch with WAZOO = Washington Area ZR-1 Owners Organization. Great owner resource.

Lastly, PM me if you are serious about a ZR-1, as I may be selling mine. One owner, quasar blue over saddle (~30 cars in the color combo), dead original (extra Fikse wheels in the photo), all service records, 53K miles. I am retired and need to reduce the fleet.
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One of my favorite cars!

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You can have lots of fun with them too. I drive mine daily, and my daughter co-drove it with me at the autocross last Saturday. We had a ball, and she even managed to spin it...twice.
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I agree, mostly. Once I sorted all the stuff on mine caused by sitting in a warehouse for 15 years, it's been absolutely reliable as a brick (touch wood). The single worst job I did was the water pump, which was totally shot when I bought the car. I should have just pulled the whole front clip, would have been easier. Total ***** of a job with very little room to operate. I just did the same job on the 308 and wow what a night and day difference, the 308 was a total breeze. But once everything was done, I've put about 5000 miles on it in just a few months including a couple 800 mile trips, and it's a great car. I love the early seats. They fit me like a glove and are so comfortable, might be the best seats I've ever had in a car. But if you're a widebody you might not like them much.

 

Tremendous and actually quite a special car.

 

Love the engine, one of the best looking engine bays in a modern car.
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I had 1995 #401, one of the last 50 of the 448 last 1995s made, and was a founding member of the ZR-1Net.

These are excellent cars - in fact, one of the very few true exotics that the U.S. Auto Industry has produced in the last 50 years.

They have not held their value well over the years, let alone appreciated...I think one reason for that may be the number of speculative collectors who just put them in plastic bags and never drove them. Even those cars are starting to depreciate...I saw a 1994 with only 1000 miles sell for the low 40,000 range this past spring.

As for the delaminating windshields - yes, they all do it. The windshield had a gold layer to help reflect infrared light (hence the little trapezoid window, which was for a radar detector, as the gold interfered with detector operation). A replacement windshield was made in the late 90s in Europe with the gold layer and original markings - but it was a custom by order and I think they must be all sold out by now.

Well worth having - and I think buyers at todays reasonable prices may as well go ahead and drive them. I bought mine at 44,000 with 15,000 miles - drove it to about 38,000 miles over about 7 years, and sold it for 28,000. Well worth having at those prices.

 

Cobraownr, I am Devilsolsi's friend that is interested in a ZR-1. PM him or I if you are interested in selling yours. I am in the market.

 

+1 on the delamination. You can see it in my pic above, the little gold spot in the upper corner of the windshield. Mine isn't too bad at all, but some have been really bad, requiring windshield replacement. The good news is regular C4 glass works just fine and is readily available, but it does lose one of those unique qualities of the ZR-1.

I think they are a fantastic buy right now. I wouldn't be a speculator, but my personal opinion is they just might start increasing soon because the oldest are about to hit that 25 year old mark. Meanwhile I drive mine every day, to the store, Home Depot, airport, you name it.

 

Any updates? Did you buy a car?