Rough idle,hard to start.
Rough idle,hard to start.
Sir, I own a 91 Q45. the problem is the car idles rough. Also about every 10th start i have to crank it 6 or 7 times to start; other times it fires up the first time. The previous owner changed the injectors and fuel pump within the last 3000 miles. There is no engine code or lights coming on in the dash saying theres a problem. Another thing I noticed; when its hard to start and I get it started it seems to be loosing power when the accelerator is pressed , for the first 1/4 mile. Any info. you can give me would be greatly appreciated. One more thing where is the ignition control unit located?
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Haitian_King
- Posts: 2868
- Joined: Sat Jan 13, 2007 8:20 pm
- Car: 1992 Black Infiniti Q45 /w TCS
1995 Black Infiniti Q45 - Location: South NJ/PA/Canada
Re: Rough idle,hard to start. (MJQ45)
Hi. Welcome to NICO.
The injectors and pump have been replaced? Your problem with the rough idle sounds as if it could be MAF related.
http://www.q45.org/roughidle.html
If you follow the link I posted, it will take you to a guide for troubleshooting and resolving rough idling issues in the 90-96 Q45s.
Are there any fuel smells? Perhaps the PO didn't have the O-Rings on the injectors properly lubricated during install and they tore. Or even maybe he used the old o-ring from the old injector. That can also be an issue.
Another thing you can do to check the injectors is to ohm them. Follow the second posted link and it will take you to a guide for doing that as well.
http://www.q45.org/ohminjectors.html
Hope it helps.
The injectors and pump have been replaced? Your problem with the rough idle sounds as if it could be MAF related.
http://www.q45.org/roughidle.html
If you follow the link I posted, it will take you to a guide for troubleshooting and resolving rough idling issues in the 90-96 Q45s.
Are there any fuel smells? Perhaps the PO didn't have the O-Rings on the injectors properly lubricated during install and they tore. Or even maybe he used the old o-ring from the old injector. That can also be an issue.
Another thing you can do to check the injectors is to ohm them. Follow the second posted link and it will take you to a guide for doing that as well.
http://www.q45.org/ohminjectors.html
Hope it helps.
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maxnix
- Posts: 22627
- Joined: Mon Jul 22, 2002 8:11 pm
- Car: 1995 Infiniti Q45
1995 Infiniti Q45t
2000 Infiniti Q45
Re: Rough idle,hard to start. (MJQ45)
And do read the timing chain guide article before you do anything else.
Re: Rough idle,hard to start. (maxnix)
I believe I am having the exact same problem, my check engine light is still on as well.
I assume it has something to do with the fuel pressure, my 8th injector has a trail of fuel running down the plenum there, and theres a couple drips along my hoses underneath the plenum as well.
Starting it takes holding it on crank for like 15 seconds and then it fires up, but coughs and doesnt want to run. Using the throttle to keep it idling works until it runs under its own power - then it ran great.
Let me know if you have a similar problem man, check out your fuel hoses and poke around for leaks
I assume it has something to do with the fuel pressure, my 8th injector has a trail of fuel running down the plenum there, and theres a couple drips along my hoses underneath the plenum as well.
Starting it takes holding it on crank for like 15 seconds and then it fires up, but coughs and doesnt want to run. Using the throttle to keep it idling works until it runs under its own power - then it ran great.
Let me know if you have a similar problem man, check out your fuel hoses and poke around for leaks