1977280Z

I have loved Z cars for a long time, but do not know a lot about the fuel injection. I am currently restoring a nice 77 280 Z car which has been sitting for 10 years. It will only start on starting fluid, and will sit at a high idle, but will not take gas. I have played with just about all the fuel injection components, and tried to test as many as i could. Getting what little knowlege from Haynes, Chilton and Claymer manuels, Haynes being the most useful. I am not sure if i adjusted the throttle valve switch right. Could it be the air flow meter? Have about 5 cold start valves, and none seem to be working. Among other problems, cant pull the timing mark to correct position, when it does run. Seems to be way advanced. any comments or helpful anything would be great! Thanks

SleeperZ

You may have more than one thing wrong. For sure it sounds like your throttle position sensor (TPS) is not making contact at idle. If you can confirm it is, or once you fix it, then recheck the ignition timing and adjust it if necessary. If the ECU thinks the engine is off idle, it advances the timing to a cruising ignition advance.

If your cold start solenoid is not working, and your symptoms indicate it's not, you may have a bad electrical connection there as well. A good test lamp will show whether you have power to the solenoid.

I would not suspect the airflow meter - that much maligned piece of equipment is quite robust and fails less often that you think. Personally, I've replaced them twice for various reasons, and it's always been something else wrong (same thing for ECUs).

'78ZXT

1977280Z

Soooo... If my TPS is not making correct contact, the ECU will jump the timing?? I got the car into firing position #1, and checked the position of the timing chain, which looked correct. But the shaft off of the oil pump was not alligned correctly with what the manuel shows where it should be, so i alligned it 5 degrees of the studs, or whatever it was. could this be a factor?? back to my TPS, if the car is running, it will not take gas!! Anything over just a fraction of gas will make it bog out! what might that pertain to? Also another quistion off of the engine. Could I put 260 bumpers on my 280?? I have real nice 260 bumpers, and those 280 ones are just plain ugly... but any suggestions would be great!! Thanks- Merk

SleeperZ

It sounds like you need to make sure everythig is properly aligned first. Check your cam timing by putting the crank pulley at TDC, and making sure your cam gear is aligned with the marks on the cam tower. Only then you should you align the oil pump drive tab in the proper position for #1 spark. Then make sure the TPS is closed (has continuity) in the idle position, and adjust the ignition timing to the spec. If you still can't get any action when you press the gas, the TPS may not be coming off the idle position.

Search the web or the Z forums - I have seen 240/260 bumper conversions done on the 280, and they look very nice. I just took mine off - I agree, they are plain ugly.

'78ZXT

RandyU

Have you connected a fuel presure gage to this thing? It sounds like it may not be getting enough fuel. Filters, lines pump, can all be a problem. Just because it is getting gas doesn't mean the pressure is right. It should have 30 lbs at idle or you will have trouble.

Also you said you have been doing some engine work. Did you reattach the big vacuum line into the valve cover? Sound silly but but I spent a couple hours on mine when I first got it before I realized this was detached and it wouldn't run. Also, you don't have the air intake tube between the air flow sensor and the throttle body removed do you? Or other big vacuum lines. Sounds silly but that is how mine was when I bought it, not running.