Had fuel pump and fuel pressure regulator diaphragm replaced, now no start?? - Third Generation F-Body Message Boards

quisterio · 03-06-2010, 01:43 AM

So my fuel pump went out a couple weeks ago... It wasn't holding any pressure at the fuel rail, it turned out to be a bad check valve..

During the period of trying to diagnose the "no pressure at the fuel rail" issue, I replaced the diaphragm in my adjustable fuel pressure regulator. All I did in order to replace it was loosen up the passenger side runner, pull off the plenum, remove the cap covering the diaphragm, replace it, put the cap back on, tighten everything back up, reattach all vacuum hoses, viola, brand new part.

We had a dealership replace the fuel pump, the pump now produces pressure at the fuel rail like it's supposed to, so everything is good there.

NOW my problem isn't a lack of fuel pressure but a no start problem.. Now when I try to start the car the process goes like this...

1. Crank the motor over
2. Motor "fires" up a little bit, as in I can smell fuel, and hear things ignite, so I've gotta be getting spark and fuel, but it doesn't allow the motor to run.. It's basically a couple sputters and then instant silence..
3. Repeat until I get angry enough to stop..

The motor is acting the exact same way it usually does when the IAC is fully closed during diagnostics mode.. As in the motor isn't getting any air??

I have made sure that all parts on the plenum and intake are tight as not to allow vacuum leaks, same with all vacuum hoses, they are all accounted for and connected..

My cap and rotor are brass and less than a year old, my ignition module is almost 2 years old (If this was bad it wouldn't even attempt to fire off right?) My MSD coil is 2 years old also.. Pick-up coil I have no idea...

Why would the car not want to run all the sudden? Before the fuel pump went out the car would run just wonderful, and now that it's fixed it won't run for anything... The only Idea I've got is to replace the IAC valve and see what that gets me..

KNBlazer · 03-06-2010, 02:09 AM

Check your spark by taking the plug wire off and visually confirming you have spark, spark may be weak... also double check every wire where you replaced parts... it could be a coil or an ignition module...

87IROC-DAN61 · 03-06-2010, 02:33 AM

Quote:

Originally Posted by quisterio

So my fuel pump went out a couple weeks ago... It wasn't holding any pressure at the fuel rail, it turned out to be a bad check valve..

During the period of trying to diagnose the "no pressure at the fuel rail" issue, I replaced the diaphragm in my adjustable fuel pressure regulator. All I did in order to replace it was loosen up the passenger side runner, pull off the plenum, remove the cap covering the diaphragm, replace it, put the cap back on, tighten everything back up, reattach all vacuum hoses, viola, brand new part.

We had a dealership replace the fuel pump, the pump now produces pressure at the fuel rail like it's supposed to, so everything is good there.

NOW my problem isn't a lack of fuel pressure but a no start problem.. Now when I try to start the car the process goes like this...

1. Crank the motor over
2. Motor "fires" up a little bit, as in I can smell fuel, and hear things ignite, so I've gotta be getting spark and fuel, but it doesn't allow the motor to run.. It's basically a couple sputters and then instant silence..
3. Repeat until I get angry enough to stop..

The motor is acting the exact same way it usually does when the IAC is fully closed during diagnostics mode.. As in the motor isn't getting any air??

I have made sure that all parts on the plenum and intake are tight as not to allow vacuum leaks, same with all vacuum hoses, they are all accounted for and connected..

My cap and rotor are brass and less than a year old, my ignition module is almost 2 years old (If this was bad it wouldn't even attempt to fire off right?) My MSD coil is 2 years old also.. Pick-up coil I have no idea...

Why would the car not want to run all the sudden? Before the fuel pump went out the car would run just wonderful, and now that it's fixed it won't run for anything... The only Idea I've got is to replace the IAC valve and see what that gets me..

Hello quisterio!!

You said that the dealership replaced the fuel pump, did they have this no start problem also?

Try resetting your IAC valve, and check out your TPS voltage also!!

quisterio · 03-06-2010, 02:46 PM

I tested for spark by pulling the wire off the coil and then cranked the motor, it went crazy with spark, so that's good...

Used a fuel pressure gauge to test the fuel pressure, when I turn the key to prime the gauge jumps straight to 43 psi, then slowly but surely starts to bleed off...

How fast should my fuel pressure be bleeding off? and even if I do have a problem with it bleeding off wouldn't the car still run with the fuel pump engaged and running???

I swear I don't know if the timing is outta whack or what... but i've got spark, fuel, and pretty sure air.. I don't know what the next thing to look at is...

Could a bad pickup coil be the cause of this?

KNBlazer · 03-06-2010, 02:52 PM

Quote:

Originally Posted by quisterio

I tested for spark by pulling the wire off the coil and then cranked the motor, it went crazy with spark, so that's good...

Used a fuel pressure gauge to test the fuel pressure, when I turn the key to prime the gauge jumps straight to 43 psi, then slowly but surely starts to bleed off...

How fast should my fuel pressure be bleeding off? and even if I do have a problem with it bleeding off wouldn't the car still run with the fuel pump engaged and running???

I swear I don't know if the timing is outta whack or what... but i've got spark, fuel, and pretty sure air.. I don't know what the next thing to look at is...

Could a bad pickup coil be the cause of this?

check the spark at cylinder #1 ... take off the boot and stick a screwdriver in it then place it against ground about 1/2 an inch and have someone crank it for you ... you could have bad rotor or cap... or an ignition module, don't know the order of operation when it comes to spark, pulse, and all the other good stuff...

quisterio · 03-06-2010, 03:06 PM

Wouldn't a bad ignition module keep me from getting any spark at all? The last time my ignition module went bad the car would just randomly die and not even fire...

The cap and rotor are the brass version and less than a year old... Spark plugs have less than 200 miles on them.

If the diaphragm is bad then there will be fuel coming out of the vacuum port on it right? Mine isn't doing that...

And Dan, forgot to mention.. Yes, the dealership had this same exact problem.. That's why the car is still sitting in their parking lot as I type this... I've been tinkering with it 20 ft from their building lol

I also put in a brand new IAC this morning too, no go... I also unplugged the TPS and tried to start it up, still a no go..

KNBlazer · 03-06-2010, 03:46 PM

Quote:

Originally Posted by quisterio

Wouldn't a bad ignition module keep me from getting any spark at all? The last time my ignition module went bad the car would just randomly die and not even fire...

The cap and rotor are the brass version and less than a year old... Spark plugs have less than 200 miles on them.

If the diaphragm is bad then there will be fuel coming out of the vacuum port on it right? Mine isn't doing that...

And Dan, forgot to mention.. Yes, the dealership had this same exact problem.. That's why the car is still sitting in their parking lot as I type this... I've been tinkering with it 20 ft from their building lol

I also put in a brand new IAC this morning too, no go... I also unplugged the TPS and tried to start it up, still a no go..

yes an ignition module will play with your soul... you are getting crank, but no ignition right... engine turns over...

It's a good idea to have a spare of each of the following... ignition module, ignition coil, cap and rotor, and a ignition coil wire... just as an emergency kit... I have a few coils, one in my car in the back storage compartment next to the quarter panel, then I also have one at home and a couple of ignition modules, just for diagnostic purposes... currently I am running I think Borg Warners top of the line... but as my back up I have an Accel module and the original one that is still in working condition...

...

quisterio · 03-06-2010, 08:35 PM

Quote:

Originally Posted by KNBlazer

yes an ignition module will play with your soul... you are getting crank, but no ignition right... engine turns over...

It's a good idea to have a spare of each of the following... ignition module, ignition coil, cap and rotor, and a ignition coil wire... just as an emergency kit... I have a few coils, one in my car in the back storage compartment next to the quarter panel, then I also have one at home and a couple of ignition modules, just for diagnostic purposes... currently I am running I think Borg Warners top of the line... but as my back up I have an Accel module and the original one that is still in working condition...

...

Yes, I am getting spark.... As I mentioned earlier I pulled the wire off the coil and cranked it just to verify that it was sparking, it arced like crazy...

The engine turns over, and then spits and sputters acting like it wants to start up, but it doesn't.

My ignition module has been replaced since I've had the car... When it went bad the car would die at completely random times... replaced it and no more of that.

New question... Would a pickup coil cause the problems I have mentioned?

Whenever i get the chance I'm gonna check the cap and rotor, just for giggles...

KNBlazer · 03-07-2010, 12:44 AM

you are getting pulse? I don't know what the order would be if the ignition module triggers the ECM to send a pulse to the injector or the ECM instructs the Ignition module to send a pulse to the injector... I would replace the ignition module, or at least take it off and get it tested...

quisterio · 03-07-2010, 12:34 PM

Quote:

Originally Posted by KNBlazer

you are getting pulse? I don't know what the order would be if the ignition module triggers the ECM to send a pulse to the injector or the ECM instructs the Ignition module to send a pulse to the injector... I would replace the ignition module, or at least take it off and get it tested...

I took the module off this morning, went to Autozone, and watched them test it.

The module passed, it took forever to get the guy to figure out how to hook it up to test it, but it ended up being good.

Now i've heard from a guy at Autozone that if I am getting spark that the pickup coil is good???

Can someone PLEASE give me some info on the pickup coil?? I have no idea what this part does or if it can be causing my problems..

UPDATE:

I checked the cap and rotor button, they both checked out with no corrosion.

ploegi · 03-07-2010, 04:30 PM

Testing an ignition module is really hit or miss. It may test good, but, in reality, it is toast. That you are getting spark, and some fuel, indicates that it isn't a complete loss. Yet.

Do you have a scan tool available? Have you tried stepping down hard on the gas pedal, and cranking? Are you getting injector pulse? Is the gas smell really bad? Are the plugs fouled? Not champions are they? (personal vendetta.... I hate champion plugs)

Something else is happening there......

quisterio · 03-07-2010, 08:19 PM

Quote:

Originally Posted by ploegi

Testing an ignition module is really hit or miss. It may test good, but, in reality, it is toast. That you are getting spark, and some fuel, indicates that it isn't a complete loss. Yet.

Do you have a scan tool available? Have you tried stepping down hard on the gas pedal, and cranking? Are you getting injector pulse? Is the gas smell really bad? Are the plugs fouled? Not champions are they? (personal vendetta.... I hate champion plugs)

Something else is happening there......

I wish I had a scan tool available.. I've tried using the gas pedal while cranking, no go. I would like to assume that I'm getting an injector pulse since I'm getting some fire, I have no sure fire way to tell though...

The gas smell is very very faint, the plugs are AC Delcos with less than 200 miles on them...

You're right, something else has got to be happening here, and it's driving me up the wall trying to figure it out... All I wanna do is drive my car

KNBlazer · 03-07-2010, 09:16 PM

Just buy a new ignition module, you'll need it sooner or later... like I said I have multiple ignition modules...

KNBlazer · 03-07-2010, 09:18 PM

what about a crank sensor? does this car have one?

...

ATX-Iroc · 03-07-2010, 09:41 PM

the pickup coil is basically like a crank sensor and gives the signal for your injectors to fire. Im dealing with this same problem right now and just cant figure it out. You can hear it stumbling trying to start but for some reason it wont. a couple of times i've been able to get it started by pumping the gas pedal really fast while cranking, the problem is that it will idle for a couple seconds then die. You can try that and see if you get any results

KNBlazer · 03-07-2010, 09:56 PM

Quote:

Originally Posted by ATX-Iroc

the pickup coil is basically like a crank sensor and gives the signal for your injectors to fire. Im dealing with this same problem right now and just cant figure it out. You can hear it stumbling trying to start but for some reason it wont. a couple of times i've been able to get it started by pumping the gas pedal really fast while cranking, the problem is that it will idle for a couple seconds then die. You can try that and see if you get any results

hmm.. I did not know that... new knowledge to my database...

.... have either of you tried starter fluid or throttle body cleaner to fire it up? I still think having a 2nd and 3rd ignition module is a good diagnostic idea...