Opinions on this ‘91 please.

[WARP TEN]

I would strongly suggest that you get your car up to Marc Haibeck rather than use a local dealer. Or at least give him a call about your symptoms. I was just at Marc's shop for our monthly lunch and he had a car in that had a noise similar to the one you have described that had been diagnosed as rod knock by his local Chevrolet dealer. The dealer then proceeded to rebuild the engine (expensive) and it still didn't run. Well it ran barely like on seven cylinders and still made the noise. As was noted above, injectors are often a culprits on these old cars, and sure enough it turns out whom ever had been working on the car had replaced injectors one at a time, with Marc finding three different brands on the car. Also one was completely dead. They were due to start it up after I left so I don't know the outcome, but I can assure you that Marc and Bob will get it running perfectly (and hopefully they won't have to rebuild the rebuild.) You are really not that far away from Marc's shop in Addison IL--probably five hours-- and having him go through a ZR-1 recently purchased can save untold headaches. It is always worth the money, and it will likely save you a lot of money over time. I did it with my '93 and my '95 and he found lots of little things that I would not have found until it was too late. Saved me lots of hassle and the cars always ran like new. Well, better than new after he did his 510 HP package on the '95.--Bob

[B17 Crew]

Originally Posted by WARP TEN

I would strongly suggest that you get your car up to Marc Haibeck rather than use a local dealer. Or at least give him a call about your symptoms. I was just at Marc's shop for our monthly lunch and he had a car in that had a noise similar to the one you have described that had been diagnosed as rod knock by his local Chevrolet dealer. The dealer then proceeded to rebuild the engine (expensive) and it still didn't run. Well it ran barely like on seven cylinders and still made the noise. As was noted above, injectors are often a culprits on these old cars, and sure enough it turns out whom ever had been working on the car had replaced injectors one at a time, with Marc finding three different brands on the car. Also one was completely dead. They were due to start it up after I left so I don't know the outcome, but I can assure you that Marc and Bob will get it running perfectly (and hopefully they won't have to rebuild the rebuild.) You are really not that far away from Marc's shop in Addison IL--probably five hours-- and having him go through a ZR-1 recently purchased can save untold headaches. It is always worth the money, and it will likely save you a lot of money over time. I did it with my '93 and my '95 and he found lots of little things that I would not have found until it was too late. Saved me lots of hassle and the cars always ran like new. Well, better than new after he did his 510 HP package on the '95.--Bob

That’s a shame the owner has to go through that, I’m sure they work hard for their money and it sounds as if it’s adding up to be quite a bit of out-of-pocket money.

To compare as best I can, I’ve been trying to locate online videos of LT-5 engine starts to see if I can find one with similar start issues I experienced. This search has helped me in that I found several vids that seem to be good examples of how the LT-5 should sound at start-up. Here is another ‘91 that starts perfectly, this is a considerably smoother start that what I experienced:

Link to vids:
Engine start at 2:39.
https://www.youtube.com/watch?v=xwr1dPx1u4c

Engine start at 1:22.
https://www.youtube.com/watch?v=pJus4_8aNxc

Once I find the right car, I will send it to Haibeck to have it gone through to address any issues. And the 510 package!... that must be one heck of a nice ZR-1! Thank you for your input.

B17Crew

[rush91]

Originally Posted by B17 Crew

That’s a shame the owner has to go through that, I’m sure they work hard for their money and it sounds as if it’s adding up to be quite a bit of out-of-pocket money.

To compare as best I can, I’ve been trying to locate online videos of LT-5 engine starts to see if I can find one with similar start issues I experienced. This search has helped me in that I found several vids that seem to be good examples of how the LT-5 should sound at start-up. Here is another ‘91 that starts perfectly, this is a considerably smoother start that what I experienced:

Link to vids:
Engine start at 2:39.
https://www.youtube.com/watch?v=xwr1dPx1u4c

Engine start at 1:22.
https://www.youtube.com/watch?v=pJus4_8aNxc

Once I find the right car, I will send it to Haibeck to have it gone through to address any issues. And the 510 package!... that must be one heck of a nice ZR-1! Thank you for your input.

B17Crew

That 1st car is the one I bought lol!! And yes, it starts smooth. But over time I do notice chain rattle on start up....it's just a LT5 thing. I have notice after an oil change ( I use Amsoil 10w-40 ) that the rattle smooths itself out. I hope you find the Z your looking for, these cars are a special piece of history

Sent from my XT1585 using Tapatalk

[B17 Crew]

Originally Posted by rush91

That 1st car is the one I bought lol!! And yes, it starts smooth. But over time I do notice chain rattle on start up....it's just a LT5 thing. I have notice after an oil change ( I use Amsoil 10w-40 ) that the rattle smooths itself out. I hope you find the Z your looking for, these cars are a special piece of history

Sent from my XT1585 using Tapatalk

It’s small world, what a great looking Z you have! I especially like the color, I currently have a Polo Green/Light Beige LT-4. The start I experienced with the ‘91 was accompanied by significant vibration and a bumping sound. I have learned it can be injectors, coil packs in need of attention, and that changing over to Amsoil/Bosch filters may quell the symptoms somewhat. This site’s members have provided excellent advice, thank you!

B17Crew