Trying to diagnose why I need to press on the gas pedal slightly to get the car to start. Basically it'll crank forever with no gas, but crank nearly immediately with a tiny amount of pressure on the gas pedal. I also need to hold the pedal or it'll stall in the first 10-15sec.

There are no check engine/SES codes on the car. The O2 sensor, MAF sensor, spark plugs and fuel pressure regulator are new. And after startup it drives fine (with a tiny amount of rough idle, +/- 100rpm)

any suggestions for tracking down this hard-to-start-without-gas issue?

 

Pre-89? Possible cold start injector issue.

 

Sounds like its not getting enough air? Clean the IAC passages (valve at bottom of throttle body) and then do the IAC and TPS reset procedure.

 

Thanks! I'll go through the whole fuel system diagnostic + cold start valve/switch. Not too long of a flow chart.

 

I'll go through the cold start valve chart first. But then check this. Although my IAC diagnostic chart from the service manual assumes it starts and idles steadily.

 

What’s iac steps engine warmed up ?

 

The IAC was unscrewed way too far (my service manual says 28 mm and it was more like 40-ish) so idle has smoothed out a lot.

Turns out my fuel pump isn't making nearly 40psi during priming so that's probably the origin of the problem. But I'm not about to do all the work of dropping the tank and fixing it. I'll just tell whoever buys it to step on the gas a little before it starts!