New ZR-1. New Issue. Stalling Once Warm.

[32valvZ]

Originally Posted by Erik

Nope. Sure haven't. Worked from the idea that they would be replaced, which means they are good. But you know how well that often works.

May have to look into what's involved with that. Is that a plenum off deal?

Per Mr. Haibeck

http://www.zr1specialist.com/HAT%20W...in%20Place.pdf

[Erik]

Originally Posted by 32valvZ

Per Mr. Haibeck

http://www.zr1specialist.com/HAT%20W...in%20Place.pdf

Thank you!
Great read. Marc Haibeck rocks.

[Erik]

The cooling system came out today. Rad in nice shape, but not too dirty. Thermostat was jammed though. No way it would close all the way. Getting a whole new set of Haibeck hoses while it's apart. New thermostat and gasket from Marc too.

It's all stuff I had budgeted for when I bought it, but maybe not quite so soon.

The encouraging thing is that everything we look at shows a car that has been well cared for, is mechanically solid, but just hasn't been used much of late. So pretty well what I hoped for.

[BigJohn]

Good time to get a larger Radiator

[Erik]

Originally Posted by BigJohn

Good time to get a larger Radiator

I looked into it, but the timing won't work. Wouldn't have one up here until later in October at best.

[Erik]

Lots of good maintenance work done, but the initial problem is still there. It feels like fuel, but it still does it with two new fuel pumps.

[Erik]

So we keep getting closer. IAC is reading way open. It's reading 150. Also, temperature readings are weird. Engine off, it's showing -40F. When it's running, 315F. I'm guessing those readings might not be totally accurate.

[Erik]

And another month went by, with this mechanic getting no closer. Sure, we got a lot of stuff done that isn't a bad thing for a 30 year old car. However, it was getting more and more obvious, that he wasn't actually troubleshooting, but rather just swapping parts. Argh!

If not for the Covid situation, I'd have it down in the US, visiting someone like Graham or Marc, and likely be up and running in a day. Sigh.

[Mystic ZR-1]

Originally Posted by Erik

So we keep getting closer. IAC is reading way open. It's reading 150. Also, temperature readings are weird. Engine off, it's showing -40F. When it's running, 315F. I'm guessing those readings might not be totally accurate.

-40F? Hope you've got green anti freeze in it...

[Paul Workman]

Originally Posted by Erik

Nope. Sure haven't. Worked from the idea that they would be replaced, which means they are good. But you know how well that often works.

May have to look into what's involved with that. Is that a plenum off deal?

From the "School of Hard Knocks": Replace AND THEN CONFIRM!

When I bought my Z from a dealer specializing in Corvette sales, the injectors were "replaced" before hand, but replaced with NOS (new old stock). Later, I measured resistance of the injectors of a WARM engine and discovered several were a couple ohms below the average of the rest, and one that was 4Ω lower (read 8 instead of the 12 ohms that was the average value for most of the rest).

That said by others too, when you first start a cold engine, both fuel pumps run for a short time, AND the ECM is in OPEN LOOP mode which means fueling is from the tables and the O2s are not being considered. After the engine temp comes up the secondary fuel pump shuts off and the ECM switches to CLOSED LOOP: a double whammy!

One of the best tools I ever bought for the Z right away was an OBD-I scanner and the Factory Service Manual (FSM). -=Jeff=- and Dominic and many others have moved to TunerPro software and the ALDL/USB cable connected to a tablet. That sounds like the way to go in lieu of a Tech-1 or other scanner(s). With that setup you can instantly see everything going on with the sensors and the tune parameters. No more having to guess and buy a lot of parts that may or MAY NOT be as good as the original parts (considering how many are made "over seas".