92 Q45 Very Difficult to Start????

[rrack]

k...I've searched and searched but still haven't quite figured this one out. Every morning when I run out to the car, I have to crank it for nearly a minute...sometimes more... to finally get it to sputter to a start. Then it's fine and runs great. It does the same thing in the afternoon when going home. It's always when the car has sat for a while. All I have done recently was replace the belts a couple weeks ago and that was it. This may just be a coincidence but that's about when these problems started. It's almost like there is a fuel problem. I know that all fuel injected cars briefly pump up the pressure when u turn the key to pressurize the lines. I can't seem to hear anything from this pump when I turn the key right before cranking it. But then, I'm not sure if I've ever heard it. Is there a specific relay that controls this function? I'm almost thinking that there is no pressure in the lines then it starts to sputter and kicks right in...I don't know. A few years ago I replaced the pump and also resoldered the fuel pump computer which had bad solder joints. Could this have happened again? I just need to fix this before I burn up a starter one morning. Any info, please let me know.

Thanks much, Robert

[maxnix]

Better check your fuel line pressure after the filter.

I think there is a FPCU relay in the trunk, but I may be wrong. Surely the FSM will clarify that fact.
Modified by maxnix at 7:58 PM 10/10/2007

[goody90q45]

Sounds like maybe a fuel injector o-ring slowly leaking and filling up a cylinder. How's your gas mileage? Has it dropped since this started? Any white or black smoke on startup? Have you changed plugs recently?

[rrack]

funny you mentioned that...that was another hunch of mine...I thought the pressure was dropping somewhere. When I finally get it started, it smokes like heck burning real rich and you can smell the fuel. the only way it will start is with the pedal to the floor and constantly cranking it for a minute or two. It will then sputter down to a normal purr of an idle. I haven't really noticed any real change in mileage. It's always been fairly bad with this giant V8. Jeez, I really don't wanna pull the injectors. Any kind of fuel product that may swell em up and give em some more life?

[goody90q45]

You can pull #1, #2 and #8 without removing the plenum. That's a 3 out of 8 (37.5%) chance you'll find the leaker. Have new o-rings on hand before you pull any fuel injectors.

[rrack]

Thanks a bunch. I'll need to break out the the gray manual and figure out what o-rings I'll need. Hopefully, if I make it to this weekend, I'll at least try and pull those. My luck it will be the very last one tho...

[maxnix]

Smoke may be from flooding the engine to get it to start. Not so sure is an O ring, but be careful of hydraulic locking a cyllinder if it is.

[Q451990]

If it's that difficult to start, you are in grave danger of hydrolocking the engine! Not to mention the fuel that seeps past the rings into the crankcase diluting your oil...

It's time to get to the bottom of this ASAP. I think I would pull the entire set of rails, then puressurize them and look for the leaks. Or send them off to Deatsch Werks for a cleaning and new seals...

Good luck!

Heath

[96Qowner]

When I finally get it started, it smokes like heck burning real rich and you can smell the fuel. the only way it will start is with the pedal to the floor and constantly cranking it for a minute or two. It will then sputter down to a normal purr of an idle.

That does sound like flooding, doesn't it? Pedal to the floor? Not good at all. More than one engine has been fubar'ed by a leaky injector filling a cylinder with fuel. Cccpman just blew his all to hell that way:

Story of a hydrolocked Q45 - leaky injector

[Q45tech]

giant V8 ??

274 cubic inches wouldn't be considered a large V8, as Chevy's 1st V8 was 265 ci in 1955 then 283 in 1957 then 327>350 currently 346ci in Camaro.

SMALL V8 is the better description.

[qship96]

uh qtech,camaro is out of production,maybe coming back real soon though,,,how about the current 427 vette with 505hp for large and in-charge ****ty pushrod v8 example

[rrack]

Sounds like maybe a fuel injector o-ring slowly leaking and filling up a cylinder. How's your gas mileage? Has it dropped since this started? Any white or black smoke on startup? Have you changed plugs recently?

Well, I think you're right. I had thought that I had figured it out...the wife filled it up with medium octane fuel. I topped it off with super (about 1/2 tank) and added a good injector cleaner. It seemed to run good for a few days and now it's doing the same old thing. After sitting overnight or after a long day at work, I'll have everything turned off..turn the key and I can hear the fuel pump running to pressurize for several seconds (longer than normal)...then crank it without any pedal. It will choke to a regular idle. However, blowing black (fuel) smoke for a couple minutes. Then it runs normal until the next morning.

Haven't changed the plugs but I have a new set of Platinums +4 sitting right here. Should I throw em in there? When you say leaky o-ring, are you speaking of the outer o-ring between the fuel rail or the lower to the intake? or is there actually an internal o-ring that could fix a leaky injector? As far as that goes, is there any way to fix a leaky injector? Sorry for the 20 questions...I'm just not familiar with injectors at all. Just want to get as much info as I can before I tear it apart...Darn it...I knew I shouldn't have sold my injectors from the blown motor... And I'm not looking forward to $168 each...

[rrack]

...just found this...will call em tomorrow and see if they'll fit...

http://www.injector.com/fuelin...e1be7

[goody90q45]

Your next step is to ohm your injectors and see how many have died (infinite ohms resistance). These could be flowing excess fuel and causing the problem. Or...I had the lower (small) o-ring give out on two injectors on two occasions early in ownership. Hard starting (like you) the first time, hydrolock (with no damage) the second time. Hold off on the plugs until you get the injectors figured out, no sense fouling new plugs.

Used injectors are cheap. A few of us have them for sale in the Infiniti Parts forum, myself included. In the meantime you can avoid any problems by starting your engine for 5 minutes every 2 hours around the clock. (LOL)

[rrack]

haha...yeah, I've actually thought of that...I've got a programmable remote start system. My luck something would go wrong and I'd see fireworks at 3am. That other website showed to include the caps and filter basket. However, I'd really like to just pick up what I need locally. Does this (http://www.partsamerica.com/ProductDeta ... er=1580370) look about what I'll need as far as o-rings? I usually use Autozone for minor stuff like this but they don't show anything on their site. If not, any ideas where I can get em quick? I emailed Joe and they don't sell the kits. I'll also throw all of them to an ohms meterl...However, I really believe that they are all otherwise working great. Once it idles down, you can't even tell the thing is running. Sometimes I need to look at the tach to make sure it's running it's that smooth.

[maxnix]

Haven't changed the plugs but I have a new set of Platinums +4 sitting right here. Should I throw em in there?

Robert, you have been absent too long! Bosch +4 are VH45DE death. Use only the OEM NGK. I use the 6 heat range in Austin.

Be sure you obtain the correct viton O rings. Joe ships overnight and regular ground is only $5 this month.

[goody90q45]

I'll also throw all of them to an ohms meter...However, I really believe that they are all otherwise working great. Once it idles down, you can't even tell the thing is running.

Once you ohm them and rule out dead or out of spec injectors (5 minutes) then you can focus on the o-rings. Removing the plugs and looking for the wet or fouled one is probably your next step....Unless you have Consult or NissanDataScan to shut off one cylinder at a time.

O-rings are only a buck or two apiece from the stealership. If you live close go to the parts counter, or buy from Joe if you can wait a couple days. In this case the $5 shipping he's offering will eat up the 25% discount.

[Q451990]

I would pull the rails, leaving the fuel line intact, and then pressurize everything (turn the key on) to see if you can find the leak.

To answer your question about o-rings, there are two per injector. The injectors are side-fed, so the fuel is pushed through the rails internally, and kept inside the rail by one upper and one lower o-ring. A pinched upper will create a leak inside the engine bay - coming from under the retaining cap. A lower one will leak directly into the cylinder.

Good luck!

Heath

[PachoC]

Knock Sensors: If these are dead, wouldn't the car be running or trying to start too rich and eventually foul the plugs?

Just a guess....

[rrack]

Knock Sensors: If these are dead, wouldn't the car be running or trying to start too rich and eventually foul the plugs?

Just a guess....

The only thing is that after it sits all day or all night and i go to start it, the fuel pump will run for 20-30 seconds before i turn the key. Haven't really timed it but I know it's far longer than the usualy 2 seconds or so. Darn it. i still can't find the o-rings. i'm considering taking them out and sending them in somewhere...

[maxnix]

I would pull the rails, leaving the fuel line intact, and then pressurize everything (turn the key on) to see if you can find the leak.

Heath

Then send them to Deatsch. Pulling the whole rail is best.

[Locknut]

rrack...I had a very similar problem...hard start...engine turned over way too long, sputtering before it finally started...and blowing some nasty smoke. I never heard the fuel pump buzz...but it was the FPCU...and it finally failed completely. The smoke was from flooding the engine trying to start it. I spent hours testing fuel pressure, rails, fuel filter, ohming injectors, checking out pressure regulators etc. etc. and it turned out to be the FPCU all along. If you've already had a problem with the FPCU...check it out. I now keep a spare FPCU and a hot wire in the trunk just in case. Good Luck!

[Locknut]

oh yeah...one other thing...my fuel pump ran "20-30" seconds same as yours after the car sat over night...must have been because the FPCU wasn't maintaining proper pressure. Of course I thought I had a bleeder somewhere...most people would...but like I said it was the FPCU all along. Go Figure.

[rrack]

That was originally my thoughts when I didn't think I could hear the pre-start pump. I may pull it and check it out again. All the injectors check out fine and it's been starting perfectly for about a week now. The only thing I did was run some injector cleaner thru two tanks. I was just about to pull everything and look for injectors. I know I had taken that pump computer apart a few years ago when I had what i thought was fuel pump problems. I resoldered all the joints and put in a new pump. Turns out it was actually the Mass Air that needed to be resoldered. My luck as usual...anyway, thanks for the tip.

[maxnix]

...it's been starting perfectly for about a week now..

Because it's been cooler? Don't know as I am not there.

But if so, check those FPCU solder joints again and look for reformed solder.

[Locknut]

one other observation...I hear alot about injector cleaners...but in my case once an injector started to go bad...all the cleaner in the world wouldn't fix it. None of the injectors that went bad on me were "clogged" with anything, they just got fried. I like the idea of adapting the rails for newer injectors unless you actually enjoy plenum jobs. My 91Q 129k mi. is a clean pristine car, had a chain guide job that wasn't necessary (been running synthetic oil forever)...still has original exhaust. The only friggin problems have been with the injectors (chicago area car)...the fuel pump, the FPCU...and now the neutral safety shutoff switch for some strange reason. Good luck pal.

[Q45tech]

Nothing in the system measures fuel line pressure!

Cold crank fuel pump rpm and duration is set by ecu based on coolant temperature!

WOT pedal to floor during cranking shuts off injectors totally!

[Locknut]

I'm still hangin around tryin to get some info on my neutral switch...so while I'm here...here is another post. Max is right on...my FPCU did the same thing before it got fried....worked on cold days...frigged out on hot ones. You know...it sits right there in the trunk underneath the rear window/package shelf and gets hot as hell on hot sunny days! Just put your hand on it and you'll wonder how the whole thing doesn't melt. Beware...mine went out suddenly and fried the relay as well...and i coasted to a stop on the express way with trucks doing 80...kids crying...ex wife calling...bad scene. Get er fixed man!

[rrack]

I think you are probably right. I did exactly that a couple years ago...Pulled it out and resoldered everthing. And now that you mention it, that is something else...this all seemed to begin starting normally the day after we had our sort of fall heat wave in the low 90s a few weeks ago. The high has now been in the mid 70s since and it's purring everyday. I got totally freaked out when I heard it may be the injectors...which can fry everything. I'm already on a replaced motor (thanks again T3 ) and I really can't afford to throw in another $3k for another. Thanks a bunch for everyone's help as usual...btw, just thought I'd mention it...I've started a side business fixing iPods and Apple systems. $65 flat rate for ipod and screens...free return shipping...a little bit more if it's the hard drive...as far as that goes, I can fix pretty much anything electronic...Holler if ya'll need anything. Just thought I'd plug that and offer any help with things I know a lot more about. Well, other than crime scenes that is... which I really hope ya'll don't need my help with that. Hope I'm not breaking the rules.