Rev and Start Issues Q45 G50

[Hogg]

Hey team,

I just bought this Q45 for $2000 and every day it seems more and more that it was not maintained properly... Unfortunately for me I love it too much.

Current Issues:-Check Engine light came on and then went off randomly it seems (When the light was on the engine lost significant power and would not want to rev up, seemed to be struggling.

-Starting the vehicle sometimes takes about 15 full seconds of the key turned in order for it to fire up

-Almost always the car starts up and then dies after about 1 second-After the Start-Death, it then starts and idles fine

-Holding the revs at a constant 1500 or 2000 or whatever RPM, they seem to fluxuate up and down by themselves enough that I can clearly see.

Please help guys, I really want to restore my Q to quality health!Any input is greatly appreciated!

Thankyou,Spence
Modified by Hogg at 8:08 PM 3/1/2008

[Haitian_King]

MAF? Pull some codes from the ECU. You try giving it a little gas when turning over? I used to have to do that when my Grand Cherokee would stall.

Damn dude, you have a big job on your hands. Good luck. I'll try to help all I can.

[Hogg]

I was thinking it might be the MAF as well, I mean after the first time it starts and dies out... The startup after that it goes well - Im thinking it could be the fuel pump possibly, not priming enough fuel.

Ill try cleaning them out, if that doesnt work Ill go for a replacement - Im afraid if I drop it off at Infiniti they wont let me take it home without thousands of dollars in replacements!

-Spence

[Haitian_King]

It may be worth it to have them do a top to bottom inspection and compile a list of all major issues. Then ignore what they say and bring the list to the NICO board. Then, the board members can go through it and do some sort of triage to get the most important things done and name fixes for it. They can also weed out whatever junk stuff that the dealer tries to make a big deal out of.

[Hogg]

Im hoping that would be the plan, the leaks arent too crucial, the emissions light is off - it just doesnt feel quite right... Im hoping they can hook it up to the diagnoses computer and see what codes come up and do whatever they do in order to make it running fresh again... Hopefully.

But yeah Ill put it on the hoist at work on Saturday - see what I can find, have one of our techs look at it, and then make my list - send it to infiniti and compare.

I love this car too much to toss it or whatever, Ive driven beaters in order to save enough money to buy a decent shape car - and then dump a lot into restoring and modifying it... I pray this is the one :/

Heh,Spence

[Hogg]

So, I changed my spark plugs the other night on my 1991 Q45.

I didnt gap them and put in Bosche plugs. Turned it over and it started and seemed to run healthy.

Left over night, I went to the autoparts store and got the replacement hose for my PCV that was leaky... Went to start the vehicle, and it cranked, started, coughed and died, Second try it did the same thing. Third - crank but no start, tried long enough that my battery is now dead.

Please help guys I want to drive my Q

[qship96]

What happened to taking it to a trained Infiniti tech for proper diagnosis?

Never use Bosch plugs in a Q45, they are problematic long term-however I dont think they are contributing to your present problems

We {and you} could guess at,and throw ideas and parts at it attempting to find the proper fix, however 1 hour labor at the dealer will prove the fastest, most economical way to a cure

[maxnix]

NAPA, Pep Boys, et al will kill your car.

http://www.infintipartsusa.com

Use them and not 3rd party improper parts. You are not driving a SBC.

If you had spent some time reading the previous posts, you would know all of this. It's not too late.

[Hogg]

It just got back from the dealer, I changed the plugs and now its not starting at all.

Infiniti said check your vacuum lines, and transmission however they said its one of the only Qs in town that they have worked on

[Hogg]

I guess I gotta pickup new cleaners and stuff for my sensors and plugs, I still have no idea why its acting the way it is - I can smell fuel after trying to start it so I think the fuel pump is working, but I could be wrong.

Would the fuel pump control unit possibly be the cause?

I really hope I find a quick fix. The Infiniti parts USA site, I hope has what Im looking for - and I hope it doesnt cost me a fortune to bring it into Canada with shipping and stuff.

Basically infiniti didnt help me at all other than tell me that some of my vacuum hoses are crappy.
Modified by Hogg at 10:01 PM 2/29/2008

[RAP]

sically infiniti didnt help me at all other than tell me that some of my vacuum hoses are crappy.

Crappy vacuum hoses, as in leaking, will cause problems starting and running for sure. Infiniti may well have provided some useful and free help?

Good luck.

Jack

[lino]

I really hope I find a quick fix. The Infiniti parts USA site, I hope has what Im looking for - and I hope it doesnt cost me a fortune to bring it into Canada with shipping and stuff.

When you order your parts from Joe, ask to have them shipped by USPS and then you won't get stung with ridiculous brokerage charges. UPS and Fedex will make you pay! Also, make sure you choose the proper USPS service you need as they have many and you can calculate time and $$ on the USPS site.

btw Joe is a super nice guy as are the others there.

[Haitian_King]

I hope he's there when I call later today. I'd call now but its much too early in Arizona. I think like a 3 hour difference? If anything it's like 6:42 AM out there.

[Hogg]

Well went through and cleaned my MAF and cleaned out a few of my sensor connections, for temp and TPS etc.

Went to start, it kinda coughed like it wanted to - and then the same thing just cranks but no start.

When I turn the key to just before start, I can hear the fuel pump whirring away, Im thinking I need to check if the FPCU is still working - if it is I have no other ideas.

Maybe it has something to do with my sparkplugs, I mean I put them in (did not gap them), turned it on and it fired up great and ran for a while until I shut it off. Left it over night and now it doesnt start at all .

-Spence

[Hogg]

UPDATE:

Jumped it, and it started.

Basically just cranking it for about a minute while its hooked up to the jumper cables. And eventually it coughed to life - kept wanting to die, shaking really violently but I gave it some throttle and it stayed alive and eventually hummed into idle.

Opened the hood, and theres fuel dripping off of the fuel rails and it reeks. Mainly it was dripping rapidly off of the tiny piece of hose connecting the two fuel rails in the middle of the engine banks.

Im really hoping to take the plenum off and replace all the hose - and make sure everythings tight and not leaking in any way.

Any more advice or tips on having similar situations would be great.

*Possibly figured out, touch wood*

[96Qowner]

Im really hoping to take the plenum off and replace all the hose - and make sure everythings tight and not leaking in any way.

Any more advice or tips on having similar situations would be great.

*Possibly figured out, touch wood*

Yeah, this is your best route. Don't blame the previous owners too much - after this much time, those under plenum hoses are shot to hell. They're gonna crumble when you go to pull the plenum. Have you read up on the procedure? It's an aggravating task. You'll also want to pull the fuel rails and make sure your injectors are alright - maybe send em off to Deutchwerks.