• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

I have spark, fuel and it cranks but no start

Y

YeahRight

New member
2004 GTP. Fuel pump died so I replaced that. Went back to start the car and it was no start after several prime cycles. Let it sit for a bit and I was able to start it again once but that's been the only time. After it wouldn't start again I checked the codes and it had a pending crank sensor failure. So, I changed the crank sensor. Still nothing. The fuel pump runs, I've put a timing light on each of plug wires and I have fire to each. I stuck an LED in one of the injector plugs to see if they're firing, cranked it and no light. So, it seems the injectors aren't firing for some reason. What would cause that? I would think if I have spark the ignition model is working correctly and sending signal to the computer to fire the injectors. I have the Torque app and it shows it's cranking at around 200rpm so it's outputting from the crank sensor at least. I'm really scratching my head here. I have a hard time believing the computer died the same time as the fuel pump and crank sensor. Either way, it's been a busy couple days of troubleshooting & I'm out of ideas...
 


I'm sure you already checked, but do you have the injectors plugged in?

edit for more ideas: I would check for voltage at the fuel pump as well.
 
Yes, they're all plugged in. I only unplugged one to test & see if there was any power there. Also, with a test light there is power to the injectors when you turn the key on but they don't cycle for the prime or when the engine cranks.
 
maybe the fuel pump isn't getting power, maybe the fuel pump didn't go out like you thought, but wasn't getting any voltage.
 
The fuel pump is now running. I can hear it run the prime cycle when I turn the key on and I took out the schrader valve on the fuel rail and hooked up a hose, pumps plenty of fuel when you crank it.
 


I would test each injector plug, see if any are getting power. If at least one lights up, it is most likely the connections to the injectors or the harnesses, if none are I would check the connections to the PCM, see if there is a dirty plug or any broken wires there.

There's two things that can disable all of the injectors in the PCM, traction control and the speed limiter, if that gives you any ideas...

And like I always say, check and clean every ground location you can find.
 
injectors will only flash when the key is turned at first, to prime the engine, they wont flash again until the engine fires up.

try starting fluid, see if it will run off that, if it wont you got a ignition issue.
 
Ok, was able to get the car to start and run with starting fluid after about 20 tries it stayed running on gasoline. Ran it for about 5 min. Shut it off and wouldn't restart again. Now, it fires a little every time you turn off the key then restart cranking but there is no fuel for it to take off & run.

I decided to replace the fuel filter since the car has 205k and it's never been replaced in the 28k I've had the car. My only problem there is I'm not sure which fuel line goes on which inlet of the filter. One is longer than the other but they're both the same size. I found a video of someone replacing one & I put it back on the way that one was hoping it's correct...

But, still no start. There's plenty of fuel up at the rail, it spurts out all over it I push in the valve. If the computer was bad I wouldn't think I could get it to run at all. Same for the ignition module. I can't remember, does the oil pressure switch cut fuel?
 
if it ran on startling fluid its a fuel issue, id start looking for a blown fuse maybe, or rubbed through wires near the injector harness.

most filters have a arrow on them noting the direction of flow.
 
Yes, it's definitely a fuel issue of some sort. All fuses are good. The injectors have power when the key is on. They don't seem to be getting the switched ground signals from the PCM.

The fuel filter is strange. This is the "returnless" system. One inlet is pressure fuel, one is return and on the opposite side of the filter is what goes to the front of the car. The problem is neither of the lines say which is which come from the tank & on the filter is has stamped "outlet" & "rtn" Uhh, ok. Both have the same connection type. The only way I can think to figure that part is take off a connection & cycle the pump to see which one is pressure. That still leaves the question of which is which on the inlet side of the filter.
 


Just tried to start it after unplugging the MAF. No go. Every single crank the engine fires for about 1/2 a second up to 800ish rpm and dies. I'm guessing this is from the prime cycle but the rest of the fuel never comes.
 
If you've got two people you could use a DMM while you are cranking it and if you got it running on starting fluid to see if the fuel pump is still getting 12 volts of power to keep it running.
 


It would have to be all the injectors clogged. And sporadic since it's ran twice now since I changed the fuel pump for 5min each. Same for the plugs & wires, it worked just fine before changing the fuel pump.

What's DMM? The engine will run on starting fluid as much as I want to spray it (takes 2 people). Like I mentioned above, twice now it has taken off & run like normal. Once I shut off the engine it will not restart again. It goes back just just firing for a half second when you first start cranking. Then you have to turn the key back off & on to get it to fire again. The fuel pump runs when it's cranking, yesterday I took out the schrader valve from the fuel rail & hooked up a hose. Pumped out a quart or so while cranking. I'm fairly certain the pump is working correctly. I think it's the injectors are not getting the pulse command signal for whatever reason. The 2 times I got it to run it was from turning the key off then back on to crank over & over, until it started. But I've only been able to get it to happen twice.
 
If you replaced the crank sensor that it needs to have a case learn. Do you have scan software to do that? Can needs to running to do that.
 
You must log in or register to reply here.
Back
Top