Stalling

[87GMQ]

1987 grand marquis stalled in traffic and was hard to restart, took about 40 seconds of cranking until it finally started. felt some hesitation while accelerating too. Brand new fuel pump (Delphi) and filter. Any thoughts?

[Tiggie]

Everything heat soaks in traffic, so I would lean towards something electric. Now that it's okay again, it will be hard to tell for sure, and with the quality of aftermarket parts, I wouldn't go throwing parts at it yet.

When you cranked it for forty seconds, did you have the accelerator down? All the way down won't Fire the injectors. But also 40 seconds of cranking without the pedal all the way down should flood it if it's getting fuel.

[DerekTheGreat]

What Tiggie said.

Years ago I was a "custodian" to an '89 Town Car. It would sometimes take a good ten seconds of cranking before it lit off. It ran great when it started though, so I never investigated it further. Sometime later after the next owner had it, he reported the fuel pressure regulator was the culprit. If I was you, I'd check the fuel pressure, should be something like 35 - 40psi key on, engine off IIRC. I'm trying to remember (yes, it's hurting my head to do so) and I think once the engine starts and vacuum hits the regulator, pressure goes up to 40psi or at least increases.

Also worth taking off the air cleaner tube and peeking at/cleaning the throttle body blade and IAC out while you're there. Check your throttle position sensor and intake air temperature sensor too. When my '88 is hot from a 1hr+ summer expressway jaunt, it'll typically stall immediately if it's shut down and then restarted within 10 or 15 minutes. I haven't futzed with it as a little throttle jab gets it to go just fine and the thing is still netting me 22-24mpg on the highway.