91 w/300 six, will not restart when warm
#11
Jumping the car does nothing to improve the ground for the starter if there is corrosion at a ground point it will still be there even if a second vehicle is providing power.
I did put jumper cables from the negative post to the chassis and then to the engine to create a solid ground. No improvement.
Still, this problems baffles everyone who has tried to figure it out.
It has been this way for a few years. The PO changed everything and nothing worked. He only used it as a yard truck so he put up with it.
My thought now is that one of the fixes was bad. like they got a new starter that was bad from the REAMAN and so it didn't fix the problem they moved on an tried something else. By they I mean a very reputable old school garage in our town. Not some kid plugging in a scanner.
I'll keep you posted.
#12
It could be something as obvious as alternator. What you need is a multimeter and test current flow at startup. But my guess would be something along the lines of a failing ignition coil, pip sensor, or ect sensor. All 3 a notorious for "killing" engines but will also prevent starts after truck is at temp.
THey did change the coil. What is the PIP sensor and ECT sensor';
#15
I've been doing lots of research and I'm closing in on some possibilities.
First, when i say hard starting I mean that it turns slowly or not at all. The trucl always start instantly if it gets a few good turns.
It only has 66000 miles and it shows. It was garaged for much of its life, there is almost no corrosion any where.
I read where this problem could be caused be leaky injectors or a clogged catalytic converter.
That really makes sense.,
Assuming injecots, what's the best way to diagnose and treat the problem?
Thanks
Dave
First, when i say hard starting I mean that it turns slowly or not at all. The trucl always start instantly if it gets a few good turns.
It only has 66000 miles and it shows. It was garaged for much of its life, there is almost no corrosion any where.
I read where this problem could be caused be leaky injectors or a clogged catalytic converter.
That really makes sense.,
Assuming injecots, what's the best way to diagnose and treat the problem?
Thanks
Dave
#16
Ok, i think i have confirmed the injector leaking into the cylinder
I switch to the forward tank which does not work- fuel pump does not come one. I cranked the truck, it cranked continuously and evenly.
Then i switch tanks again, engaged the fuel pump and the engine dragged like one cylinder was filled with liquid.
I switch to the forward tank which does not work- fuel pump does not come one. I cranked the truck, it cranked continuously and evenly.
Then i switch tanks again, engaged the fuel pump and the engine dragged like one cylinder was filled with liquid.
The following users liked this post:
FarmerJohn (03-03-2015)
#17
Senior Member
iTrader: (1)
Put a fuel pressure gauge on it. koeo you should get close to max pressure, then it should hold that for at least a couple minutes. If it bleeds down fast that would be one more thing to go with your theory.
Some injector cleaner in the fuel tank can sometimes help, it's usually just dirt on the seat of the injector. But maybe it just wants new ones.
Some injector cleaner in the fuel tank can sometimes help, it's usually just dirt on the seat of the injector. But maybe it just wants new ones.
#18
leaky injector?
So in google around abour this problem someone suggested leaky injectors causing hydraulic lock. Seems like that would take a lot of fuel but i did an experiment.
The truck has dual tanks but one does not work. That allowed me to starve the engine by switching to the dead tank.
When i do this, the truck cranks vigorously and then it starts when i engage the good tank.
Then i looked at the plugs, i removed one at a time and turned the engine. The engine stayed the same, dragging not turning, until i got to cylinder five and six. Then it would crank properly and start.
So, i think i have a diagnosis- back two injectors are leaking badly enough to cause hydraulic lock.
Any problem with that theory?
The truck has dual tanks but one does not work. That allowed me to starve the engine by switching to the dead tank.
When i do this, the truck cranks vigorously and then it starts when i engage the good tank.
Then i looked at the plugs, i removed one at a time and turned the engine. The engine stayed the same, dragging not turning, until i got to cylinder five and six. Then it would crank properly and start.
So, i think i have a diagnosis- back two injectors are leaking badly enough to cause hydraulic lock.
Any problem with that theory?
The following users liked this post:
FarmerJohn (03-03-2015)
#19
Senior Member
Sounds like a good place to start.
#20
Chief Mystic
Looks like you found your problem, but another cause of this exact problem, wont restart when WARM, is the thermostat.
A bad thermostat will actually keep it from turning over, if the car sits for 10-15 minutes, starts right back up.
Another cause of this is not enough coolant, but I hope you checked that! if an air bubble hits the thermostat, it can do this. It usually stalls the car out and then it wont restart for a few minutes.
A bad thermostat will actually keep it from turning over, if the car sits for 10-15 minutes, starts right back up.
Another cause of this is not enough coolant, but I hope you checked that! if an air bubble hits the thermostat, it can do this. It usually stalls the car out and then it wont restart for a few minutes.