Problem with fuel system

R

Rameerez

Low Mileage
A friend is helping me do some work on my 86 x. He fixed a crack in the exhaust mainfold and put it back with new gaskets. No problem with vacuum leak now, but when he assembled everything back the car would not run- it would start but immediately die. With the air flow meter removed the car will start and idle, but immediately dies if the meter is reattached. We've done the electrical/continuity tests on the dual relay that controls the AFM, and they check out ok. Test also shows the fuel pump is operating properly when the "trap door" inside the AFM is pushed open.

I've run out of ideas. Help!!!
 
A question..

By "With the air flow meter removed the car will start and idle, but immediately dies if the meter is reattached" do you mean the meter or the electrical harness? If installing the meter kills the engine, then look at idle and CO% screw settings. If it's when you plug it in, I dunno. Shouldn't run without it plugged in since it turns on the fuel pump.
 
I meant with the wiring harness connected but the air flow meter itself disconnected. We didn't touch either the idle or mix screws during the work.
 
Hmmm...

Either not enough air is getting in, as in some other hose is blocked (crankcase breather, aux air valve line, that sort of thing) or the fuel system isn't responding to the AFM when installed.

The AFM is a simple thing really, tells the fuel pump to run and gives a rough idea to the ECU of air flow so the ECU uses a given amount of fuel. Perhaps the mix is off.

Sometimes you can tell which way the mix is off by how much or little you need to manually open the AFM door to help it run (when installed). If you have to open the door more than the air is, then it needs more fuel. Does that make sense?
 
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