selfproclaimedv8buff

so this past week the v8 has at times left me cranking in a parking lot. it'll just crank and not fire. wasn't really dressed to check the fuel/spark on the car but after a while it'll start up and run fine. I've also noticed that the car will cut off like a fuel cut off (remembered the days from my CIS 10vt) when i really really lay into it in the 100mph+ region. thinking it may be my fuel pump just b/c i believe i have the original fuel pump. will a bad fuel pump seem to work one time and not work another? thanks.

paulfern2000

Any buzzing noise coming from the back?

MrGoodbytes

During no-start crank, does the tach bounce?

Aldo

Reference sensor, crank sensor -change em.

Kneale Brownson

A dying fuel pump could be failing to supply sufficient pressure that you'd get poor response under heavy acceleration.

The parkinglot no-start is the classic failing Ignition Reference Sender symptom (hard hot restarts).

selfproclaimedv8buff

i was trying to pay attention for that but didn't notice any buzzing.

selfproclaimedv8buff

nope.

itsav8

I had the same issues with my ol Pearl Beast, but with the addition of stalling out at lights & not being able to restart.

But do you hear the fuel pump prime when you turn the key & all the lights come on rite before you try to start?
But I still think it's the RPM sensor.
If it is I would suggest replacing both RPm & Ign. Use the 5ktq sensors..they are a bit cheaper than the V8 sensors.

MrGoodbytes

Does the pump prime when you turn on the ignition?

I know on the 944, which has the same ignition system, the DME Computer will not energize the fuel pump unless it detects the engine spinning somewhere around 200-500rpm. It gets that signal from the speed & ref sensors.

Kneale Brownson

Same on V8s and 200q20vs: That is, pump doesn't get power unless ECU detects engine turning. I think the ECU needs to see appropriate signals from both sensors to kick on the fuel pump, but I don't know that for sure.