280Z Difficulty starting

[Captain Obvious]

Mario,

 

The EGR stuff sounds OK. Might be a small leak past the valve, but you have at least ruled out a gross problem there.

 

As for the resistance measurements you got off the AFM, you're right...  The measurements you got between pins 6-8 and 8-9 sound fine, but the measurement between 7 and 8 doesn't seem like it agrees with the test result of "Continuity (Small Resistance)" that is listed in the 75 EFI manual.

 

However... I took a look at the 1980 EFI manual (which covers 75 through 80) and that newer version has a different answer for that test. The 1980 manual says you should see about 150 Ohms between 7 and 8.

 

So it seems you may have highlighted a mistake in one of those two manuals, but I don't know which one. I'll try to take a couple measurements off my car today to figure out which source is correct and which is screwed up. I suspect the 1980 manual is correct which would unfortunately mean that you haven't yet found any anomaly to explain your car's behavior.

[Marios280Z]

 

 I suspect the 1980 manual is correct which would unfortunately mean that you haven't yet found any anomaly to explain your car's behavior.

Yes...this is frustrating. I'm almost to the point where I want to load up my gun and start the shotgun approach by replacing parts, one after another until she starts properly...OK, fine, I will probably not do that but you get my point

[rcb280z]

Mario, I get your frustration all to well. Being in a state that wants to eliminate cars like mine from the roadways is making it so difficult on owners like myself. Just keep plugging away at it. It's ok to get frustrated. Sometimes that helps me. I'm just starting to dig into mine again because of an issue I wont talk about in your thread. I will start a new one describing mine later. Hang in there.

[Captain Obvious]

Haha! Just remember to keep it in perspective. There are lots of Z owners who just can't get their car to run. At all.

 

You've got a small issue where it's a little tough to get it started the first time when the engine is stone cold. Other than that, you're OK, right? 

[Marios280Z]

rcb280Z, I'm glad tat Iowa does not even heave emission control...

 

Haha! Just remember to keep it in perspective. There are lots of Z owners who just can't get their car to run. At all.

 

You've got a small issue where it's a little tough to get it started the first time when the engine is stone cold. Other than that, you're OK, right? 

Yeah, in a retrospect I'm lucky. 

There is one more thing that needs investigating, but I won't get on that subject until the starting is resolved.

[rcb280z]

rcb280Z, I'm glad tat Iowa does not even heave emission control...

 

Yeah, in a retrospect I'm lucky. 

There is one more thing that needs investigating, but I won't get on that subject until the starting is resolved.

 

Your are lucky Mario. My Z runs clean as far as Im concerned just not clean enough for CA standards.

[Patcon]

Wasn't California recently considering moving the date up to something like 1979 for smog? Sorry for the "thread jack"...

[Marios280Z]

It's been a while since I looked into this. But there is something worth mentioning. Now that mornings are quite cold, high 30a low 40s, the car has been starting at the first attempt. It's an indication that the CSV is actually spraying the extra fuel (I also confirmed it with the injector in the jar test the other day on the cold morning). Just as starting fluid in a warmer day will make it start right up, the CSV helps. But this is just masking the issue. Some of you have mentioned that you entirely removed the CSV, and have no problem starting. One thing I would like to throw out there for consideration that I was told is vapor lock. What do you guys think about this theory? Anyways, there is not much more time left for me to drive this season. Car will probably go into storage pretty soon here. Maybe it will fix itself over the winter and the problem will be gone in the spring, no?

[Zed Head]

I was one that said I had removed my CSV, and the engine does start okay, but is slow on days when the engine bay is cold.  Pretty sure it's all about vaporization.  If the morning is foggy and it's cold out, the best starting routine is to crank it for a few revolutions, let it sit for about 10 seconds, then start it.  Otherwise I do get extended cranking time.

 

On a cold morning, but with sun on the hood of the car, it will start right up.  The only decent explanation, to me, is cold metal hindering fuel vaporization.  I also mentioned holding the throttle open while cranking as a way to get it to start faster, hence the discussion about clear-flood mode.  "Vapor lock" doesn't happen on the EFI cars, they're high pressure systems.  Plus the fact that vapor lock is a heat problem, and yous is a cold one.

 

I can understand wanting a quick start like a modern car.  Just not sure it's easy to get to.  Note also, that the fuel manufacturers change the formulation in the winter time for faster vaporization.  This may be applying in your case.  New fuel blends start flowing in September, apparently.  About time for more "hot start problem" posts.

 

Here's some articles.  It's a fun topic.  Couldn't find any Iowa specific pages.

 

http://newsroom.aaa.com/2013/06/what-is-the-difference-between-summer-and-winter-blend-gasoline/

 

https://blog.gasbuddy.com/posts/U-S-moves-back-to-winter-gasoline/1715-584804-2663.aspx

 

http://www.pennlive.com/midstate/index.ssf/2015/09/gas_prices_to_be_pushed_lower.html