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Discussion Starter · #1 ·
2004 GC Laredo,; Wont start but will spin over good. Neutral safety switch replaced, has gas, will run good once it starts.
Air filter good, vacuum lines good; heres the good part:
Went to Advance today to get some items and it wouldnt start again, went to speak to one of the guys i spoke too on other occasions and one of the other employees came up to me in the vehicle while i was trying to crank up. After he observed what was happening, he suggested a small shot of starter fluid....... i knew it wouldnt hurt on a small spray......, and it cranked up after about 2 sec. delay to get the fumes into the engine. After it starts, it runs fine, till i have to turn it off again. Could it be any of the sensors on the intake(TPS, MAP, IAT, ....no MAF sensor) i was told maybe crank position sensor.
Now it starts pretty much every time w starter fluid....and if i crank and press the pedal it may crank up....but obviously that wont work w a HS student who expects it to work normally.

Will try starting it tomorrow and then immediately try to start it again and see if its a time thing, maybe fuel filter/pump.

also the Evap purge valve is bypassed, so the engine is pulling a good vacuum in the tank......or should it be pressurized and the fuel pressure not staying up to proper pressure?
 

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My 1st question is why is the purge valve bypassed?
2nd question, did you have the PCM scanned for any trouble codes?

Fuel fumes in the closed EVAP sytem are stored in the charcoal canister.
When the engine is 1st started the purge valve typically opens allowing those stored fumes in the cannister to enter the engine's vacuum intake system.

Either this has something to do with the purge system or a fuel delivery related issue at startup.
I'd get the purge valve sorted out first before diving deeper into this.
Besides depending on your County, a faulty EVAP system could fail the bureaucratic emission test.
 

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Discussion Starter · #3 ·
My 1st question is why is the purge valve bypassed?
2nd question, did you have the PCM scanned for any trouble codes?

Fuel fumes in the closed EVAP sytem are stored in the charcoal canister.
When the engine is 1st started the purge valve typically opens allowing those stored fumes in the cannister to enter the engine's vacuum intake system.

Either this has something to do with the purge system or a fuel delivery related issue at startup.
I'd get the purge valve sorted out first before diving deeper into this.
Besides depending on your County, a faulty EVAP system could fail the bureaucratic emission test.

After having to do some electrical work on the ground clamp on the battery and reinstalling it, the CE light is now OFF.

Cleaned and checked all connections on all sensors and vacuum hoses on intake while it was cold. Still trouble cranking. Could IAC not be open, fuel pressure not holding, filter, pump.(those last 2 prob not, due to once its cranked and running, its stays running.
 

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After having to do some electrical work on the ground clamp on the battery and reinstalling it, the CE light is now OFF.

Cleaned and checked all connections on all sensors and vacuum hoses on intake while it was cold. Still trouble cranking. Could IAC not be open, fuel pressure not holding, filter, pump.(those last 2 prob not, due to once its cranked and running, its stays running.
I'm confused by the bold type above^.
Once and for all. Do you have a cranking issue or the engine cranks but won't start or it does start but not stay running?

And what was the CEL code when the CEL was on?
You can still get the PCM scanned and hopefully the code was stored but not active anymore.
 

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Discussion Starter · #5 ·
I'm confused by the bold type above^.
Once and for all. Do you have a cranking issue or the engine cranks but won't start or it does start but not stay running?

And what was the CEL code when the CEL was on?
You can still get the PCM scanned and hopefully the code was stored but not active anymore.

Didint get code read.........yet.

engine cranks but won't start.........will start after about 3 tries.(and will stay running)

Possible fuel regulator/fuel filter(on frame rail) or pressure from pump?
 

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Didint get code read.........yet.
engine cranks but won't start.........will start after about 3 tries.(and will stay running)
Possible fuel regulator/fuel filter(on frame rail) or pressure from pump?
Ok its crank no start but engine does start after a few crank attempts.

One easy experiment is leave the ignition on without cranking the engine for around 10 seconds then crank the engine.
This will allow the fuel pump to prime the system before actually starting the engine.
If that works then its probably a bad fuel check valve or a leaky injector depressurizing the fuel rail.

Might want to do or have done a fuel pressure test and a fuel pressure leak down test to verify if this is the problem.
 
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Discussion Starter · #7 ·
Ok its crank no start but engine does start after a few crank attempts.

One easy experiment is leave the ignition on without cranking the engine for around 10 seconds then crank the engine.
This will allow the fuel pump to prime the system before actually starting the engine.
If that works then its probably a bad fuel check valve or a leaky injector depressurizing the fuel rail.

Might want to do or have done a fuel pressure test and a fuel pressure leak down test to verify if this is the problem.
OK, tried the 10 sec. pump prime w the switch on but not crank....................no help

Why would it start w a SMALL shot of starter fluid into the filter box, then run OK. Vacuum of engine cranking over causing suction , which would suck fuel out of injectors........?

So would this seem to be filter/regulator or pump issue.......check valves leaking?
 

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You said it again 'but not crank'.
You have to get your wording more accurate or we're gonna go in circles.
So would this seem to be filter/regulator or pump issue.......check valves leaking?
I already said this:
"Might want to do or have done a fuel pressure test and a fuel pressure leak down test to verify if this is the problem."
 
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