Test for cold start valve?

[jray1942]

I have a '75 280Z w/ L28 engine.

I removed the unit from manifold.

Attached a 12v source across connectors.

There was no 'click' heard.

Valve can be actuated manually aganist internal spring an seems to be moving freely.

Is the a correct test other than the complicated one used by the FSM?

[sblake01]

I'm not sure that they click open and closed like an injector but more so they allow the fuel tha't in them to flow from/through them as long as the thermotime switch is open. I beileve the method you're using would require fuel pressure. I actually have the equipment to test them that way but I've never tried it.

EDIT: I thought about my response and decided to get out my tester and couple of known to be good cold start valves. You have to listen very closely but I can hear a sound when I apply power. Not nearly as loud as the click of a fuel injector but I did hear a sound on both valves I tested.

Edited October 14, 2009 by sblake01
more definitive answer.

[jray1942]

sblake01

Thanks for the info. and your effort to check it out. I kinda thought that there had to be pressure of some sort after reading the FSM test for the unit but was trying to find an less complicated way. I'll try it again and get it closer to my ear. (I'm old you know!) Thanks again for the input.

[sblake01]

I'm old you know!

I'm not too far behind. (assuming that the 1942 in your screenname is your year of birth)

[jray1942]

Not very hard was it? I try to keep things simple in this complicated era.

I tried your suggestion about the unit to no avail as I couldn't hear anything but I reinstalled it as I think I may have multiple issues.

I just got this car and has been sitting for years. It's in fairly good condition for a 34 year old car. The PO has had it since 1976! and it has 48,000 actual miles. I spent the first 2 weeks getting the dash lights to work without blowing a fuse.(12 to be exact!) Finally discovered a very bad dealer wiring job that had someone connect what they used to call floating ground to a earth or body ground under the center console, the last place I looked!

Here's the overall engine problem. It will start, very hard, and would idle fairly evenly. It would not take a throttle at all and would just stall out. I eventually got around to checking the timing and someone had set it -20 degrees! But when I placed it back to 7.0 degrees(0degrees on timing mark) it now barely idles at all, a stumbling 500 rpm, and I cannot set the idle screw anywhere that has any real effect. I of course still wont take any throttle. Here's what I have done:

All injectors are working. I took all of them out and inspected and cleaned them. They are at least working mechanically as I used the audio 'click' test the few times I can keep the engine idling.

I have replaced all the fuel hoses by the way.

I took off the air flow meter and checked the values as indicated by FSM and checked normal.

Pulled off and checked pressure regulator. cleaned it and seems to be ok but of course that's not conclusive. It at least was not plugged up.

By the way, I screwed up! First time! (this week!). I wanted a check on the AIR REGULATOR stead of the cold start valve. Can't read schematics anymore either. So it could still be an issue as the valve was hung up when I first took it off. I sprayed it with some carb cleaner inside and it broke loose and then began to spring back into place. The cold start valve was also removed, inspected, cleaned and tested with a 12v source and did pass the 'click' test.

So that's where I'm at right now. Drawing on your obvious experience what would you do next? I'm thinking of pulling the throttle body next. Any help is appreciated.

By the way, I used took work for some racing teams in the old CART, Champ Car, Indy Car and Atlantic's series and pulled several race transporters thru San Bernardino on the way to either Fontana, The old Ontario, and California Speedway.

JR

Edited October 16, 2009 by jray1942

[sblake01]

I'd check the fuel pressure while it's running next. I worked many years ago at the old Riverside raceway.