Extended cranking before start on '87
Thread Starter
Instructor
Joined: Nov 2006
Posts: 103
Likes: 0
From: Ft Liquordale Florida
Extended cranking before start on '87
I have changed fuel pump, fuel pressure regulator, plugs, wires, cap rotor, fuel filter, and cleaned the throttle body.
acts just like when you let a car sit over night and the fuel pressure drops.
VATS is bypassed
Anybody run into this before?
acts just like when you let a car sit over night and the fuel pressure drops.
VATS is bypassed
Anybody run into this before?
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
It is clear that you haven't changed enough parts yet. Instead of blindly installing new parts, why don't you do some diagnostic tests to find out why the engine won't start quickly. The first place I would look is for stored error codes and I would check the cold start injector to see if it is working properly.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Does the engine not want to start when hot or cold? Or both?
Things to check:
TPS for sticking or binding or high TPS voltage with throttle closed (< .7v)
High resistance in coolant temp sensor circuit or sensor itself
cold start injector
Fuel pressure
EGR operation (valve is seating properly and not staying open)
Both injector fuses
Loose ignition coil ground
pickup coil resistance and connections
Things to check:
TPS for sticking or binding or high TPS voltage with throttle closed (< .7v)
High resistance in coolant temp sensor circuit or sensor itself
cold start injector
Fuel pressure
EGR operation (valve is seating properly and not staying open)
Both injector fuses
Loose ignition coil ground
pickup coil resistance and connections
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Can you hear the pump prime the injectors at key on?
Fuel pump relay working?
If not you are waiting for the fuel pump oil pressure switch to run the pump which requires building oil pressure by cranking before switch will close.This operates in parallel with the pump relay supply
Fuel pump relay working?
If not you are waiting for the fuel pump oil pressure switch to run the pump which requires building oil pressure by cranking before switch will close.This operates in parallel with the pump relay supply
Thread Starter
Instructor
Joined: Nov 2006
Posts: 103
Likes: 0
From: Ft Liquordale Florida
It is clear that you haven't changed enough parts yet. Instead of blindly installing new parts, why don't you do some diagnostic tests to find out why the engine won't start quickly. The first place I would look is for stored error codes and I would check the cold start injector to see if it is working properly.
Fuel pump was changed because old one would stop after 30 minutes running and I would have to let it cool down before starting again
fuel pressure regulator was changed because it was an adjustable unit but did not change fuel pressure when adjusted, so I installed a "working" adjustable fuel pressure regulator
all the other stuf was just maintenance
where is this "coldstart injector located"?????
I can hear the pump charging when key is turned on
happens hot or cold, throttle open or closed
there is a sensor in the front of the drivers side cylinder head with a green wire with white stripe going to it that keeps coming unconnected between cylinder #1 and #3 spark plugs. Is this a temp sensor for the fan?
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by alecracing
there is a sensor in the front of the drivers side cylinder head with a green wire with white stripe going to it that keeps coming unconnected between cylinder #1 and #3 spark plugs. Is this a temp sensor for the fan?
RACE ON!!!
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