Finally pulled the zr-1 out of storage

[Kevin]

Haven't even touche the car this year, had someone else pick it up for me since I was out of town and couldn't get the car out before I had to leave, and I just can't be bothered with it. I'm considering selling...again. Someone talk me out of it

[We Gone]

Kevin.
All I can say is if you need to sell it do so, Just get another you will be lost without a ZR-1. Other cars may be newer and faster but there will only ever be one KOTH.. Best of luck to you.

[Dynomite]

Originally Posted by Kevin

Haven't even touche the car this year, had someone else pick it up for me since I was out of town and couldn't get the car out before I had to leave, and I just can't be bothered with it. I'm considering selling...again. Someone talk me out of it

Kevin....I understand your frustration...you did say you had a DIS Code earlier.....what was that about?

Here is another chap in the same position as you just today on CF. The reason I mention this is he like yourself just does not have or use tools and is not a fix it yourself person....so it becomes very difficult to even chase down the simple issues (most are simple with the LT5 and NOT disaster unless you suck up some bolts into the intake or blow a timing chain). What you and the chap on CF need ASAP are some friends familiar with the LT5 to drop over and take a look...I cannot say it any simpler for you

The Chap on CF PMed me just today (I get these requests occasionally)......
Hi, I hope you can help me. My 91 ZR1 has a rough idle and under load it misses badly. At highway speeds for instance, it seems to run ok on level roadway, but going up hills it sputters and misses when I apply the throttle. This happens with the power key on or off. Less that a year ago I had the injectors replaced with new FIC ones, new plug wires, new plugs and one new coil. The work was performed by the local Chevy dealer, as I am unable to do the work myself. I have checked the MAP hose and it is still on. I would appreciate any help you could give. Thanks!

Here is my quick response......but again....what this chap really needs is a guy like any number of us on this Forum to drop by with a spare ECM (maybe spare DIS) and take a look.
Hi:

Well......hmmmm....Lets start assuming....
1. Lets assume the Z ran perfectly after the Chev dealer did the work described.
2. Lets assume this issue started gradually.
3. Lets assume (BIG assumption) that the items replaced are working perfectly (no coil issues , including the coils not replaced) no injector issues, no plug issues, no plug wire issues.
4. Lets assume your vacuum pump cycles off indicating proper vacuum is reached for secondaries (even though you have another issue).
5. Lets assume you have no major vacuum leaks (plemum, IH).
6. Lets also assume you have good compression on all 8 cylinders (210-230 lbs within 10 lbs each cylinder).
7. Lets further assume it is not some rare failure of the ECM, or Ignition Module.

What we have left is fuel pressure (fuel pumps), Camshaft timing, Camshaft position sensor, maybe bad gas (water in gas).....and maybe some odd issue I have no clue from the description (like spark plugs loose).

So.....are my assumptions correct and you would have to test/verify that those assumptions are correct. Anything can happen...and can happen within minutes of installing something in new condition.

As an example...I installed a NEW Water Pump...took the Z for a spin (no pun intended) and the impeller spun off the water pump shaft giving me a rise in coolant temperature I could not imagine the cause (but I caught hold of myself and then imagined the impeller spun free on the shaft).

I guess what I would do if you are sure of the assumptions listed above....start with items not checked yet including fuel pressure, spark plug installation and maybe (something I always do on a New Z) do a compression check on all 8 cylinders.

Let me know your thoughts and post up for others to consider possibilities for you.

I will think further on the issue for you and PM you any further thoughts.

Cliff

Kevin.....what you need is a local group of avid LT5 do-it-yourselfers to help you......

[Kevin]

the dis code went away when I changed the ECM so i'm going to chock that up to a bad ecm. What I need is someone to walk me through a few things and I'll be fine...maybe. Like I said I have a friend locally who's willing to help but he doesn't own a zr-1 but he wrenches on his Ferraris.

[Bearly Flying]

One thing I found during a dynotune yesterday, I was running rich across the board, the only change was new FIS fuel injectors. It appears that the newer fuel injectors do a better job of atomizing the fuel. We dropped out about 20 % of the fuel across the table.

Only bad thing is that it will roast the tires anytime you step on it now....

[Kevin]

Originally Posted by Bearly Flying

One thing I found during a dynotune yesterday, I was running rich across the board, the only change was new FIS fuel injectors. It appears that the newer fuel injectors do a better job of atomizing the fuel. We dropped out about 20 % of the fuel across the table.

Only bad thing is that it will roast the tires anytime you step on it now....

not seeing anything to make me think this is a fuel issue