What's causing this bad start and bad throttle response?

Jorogumo4

Member
Jun 15, 2022
26
7
13
Hey guys, I'm still running into a few issues when it comes to starting up my 1985 fox convertible lx.

Originally my issue was a bad vacuum leak via the brake booster, replaced that and it resolved a lot of my harsh idle issues, but there was still some issues with stalling at stops and what not. So I ended up replacing a bad EGR Valve, and now I don't stall at stops anymore and I don't stall when shifting to reverse or drive anymore as well.

However, I do still run into this issue... When I start the car, it sounds like it cranks up just fine, but when I let off the ignition it stalls immediately. The only way to get it started from there is to hold the gas pedal while turning the ignition until the car revs up to 3k rpm then I can let go of the ignition and the gas. Once it's running like that I can give it a few more revs to 3k RPM and it runs just fine from there. No stalling, no bad idle, no issues shifting into drive or reverse, it all works fine.

However, additionally, even though I'm up and running I've got this horrible lag in the throttle, each time I press the throttle moderately you'll see the RPMs dive to like, 250, then it gases up. I'm sure these issues are linked. Some type of fuel delivery issue maybe? Idle drops because air is getting into the system but not enough fuel? I've swapped the fuel filter, and the fuel pump is delivering enough pressure, nothing wrong there. Is it time to replace the fuel injectors? I've already ran through a tank with fuel injector cleaner in it.

Here's a video of the car reving, I couldn't get it to not start this time as it only happens about 50% of the time. It seems like if the engine has ran recently it has an easier time starting.


View: https://drive.google.com/file/d/1KWyS53RfsONS38ujpSMj6B0YIqFed5-A/view?usp=sharing
 
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Jorogumo4

Member
Jun 15, 2022
26
7
13
Got to thinking, I've had a few backfires as well. Maybe it's a bad Fuel Pressure Regulator? The car is running a bit rich, can really smell the gas. Exhaust leaks as well, it's got a bad clogged up cat on it.