injector change and transmission problem

[trbo50]

I would like to seek some assistance from you experts out there who has replaced injectors on their 91 Q. Does anyone have a list of tool or special tools needed and any parts such as gaskets that I will need to perform this job?

Once in a while, the transmission will hold 3 gear and not shift into OD. When the transmission finally shifts into OD, it's a hard bang like someone did a neutral drop. The transmission was replaced by the dealer at 58k and now the car has 137k miles. Anything I can do to help with this problem? Where can I find info on an after market transmission cooler?

Thanks for the board and everyone's help.

Norman

[Q451990]

No special tools I can think of... just all new gaskets for the plenum to runner connections, new PCV hoses, new injector o-rings, and insluators for the injector ports in the runners. You should also think about replacing the coolant lines under there and the knock sensors and it's harness.

How do you know the injectors are bad?

One key point on the injector o-rings. Grease them with di-electric grease or vasoline... if not they may pinch and allow fuel to flow into the cylinder. Worst case scenario is a hydrolock at that point.

Heath

[Q451990]

As far as the transmisison, what you describe sounds pretty bad... you might try a pan drop and filter replacement and flush - but I doubt that'll help. Usually just helps maintain the current condition, but doesn't cure problems.

Have you updated the timing chain guides yet? If not I woudn't spend the $$ on a transimission or injectors and still be sitting on a engine time-bomb. You might do a search for "Timing chain" or "chain guides" if you haven't heard about this before.

Where are you located? If you're anywhere near Atlanta you're in luck... the Q mecca of the east coast is there - called T3 Automotive.

Heath

[trbo50]

Heath,

Thanks for your quick reply. I have a problem with rough idle and sometimes it feels like a mis fire and the check engine light comes on. The dealer told me the injector impedence is out of spec. It looks like I dont have much of a choice right now but to fix the car. The resale value is ridiculous but it's also difficult to justify the cost of the repair and parts.

I'm also looking for anyone's referal on the best place to buy injectors and parts. Of course cost is the driver. There are some online stores selling injectors with various color codes. Which ones do I need to buy?

Thanks,Norman

[maxnix]

Quote »There are some online stores selling injectors with various color codes.[/quote] OEM from http://www.infinitipartsusa.com . Others are cleaned used injectors and junk.

Better take a real careful look at your car after reading all the posts on maintenance, as you may be in for some serious triage.

[DAEDALUS]

Which injector? You would be able to leave the plenum on to replace injectors 1, 2, and maybe 7 & 8. A lot less labor than replacing injectors 3-6. Good info so far from all; our experience says you might have larger concerns that should be addressed either simultaneously or very soon if you're going to start putting that much money into the car. Jiggle the harness connectors to make sure you have a good connection. Raise the hood, and look above the passenger-side engine head, near the side of the plenum. You'll see 3 harness connector there, right next to the throttle cable mechanism. Jiggle them; it won't hurt. If you want, you can confirm your shops findings too by disconnecting the larger harnesses and measuring the resistance. Do a search; I'm pretty sure the procedure is detailed on here somewhere. I would definitely confirm the problem with 20 minutes of work before considering replacing the injector. Also do a search for "tran*ny coo*ler 70*268", except without the asterisks. Much info on that too.

[PalmerWMD]

All 90-93 Q45 accept the purple top injectors.Other colors may also fit for different years, but the purple ones fit all.

What is your location?

Fred...

[trbo50]

Thanks everyone! I'm in the SF Bay Area and would like to find a good shop experienced with Q45 repairs. I would appreciate any recommendations and comments on your experience with the shops.

Norman

[DAEDALUS]

Posted by Bayarea Q:

Hey Mccluredude,

Nice to see a fellow Q member in the area!! I live in Santa Rosa, and work in San Rafael. I didn't know there is an Infiniti dealer here in San Rafael. After reading your post, I think I'll stay away. The independent shop I use is great, but I doubt they would be the best to use for a tought job / diagnosis.....There name is Watt Automotive, in Santa Rosa. Phone # (707) 544-8952. Tell them you know Robert, and they will take care of you. I've had the following done there: Pan drop & transmission flush with my own mobil 1 for 200.00All 4 brakesNew front strutsOil changes....I bring own oil and filter. Charge $12.00They just bought a powersteering flush and coolant flush, so I'm going to do both soon.One of the benefits of using this shop is they give you free loaners for as long as your car is in the shop. There old volvos, but it beats renting a car! Just make sure you communicate what and how you want things done. Also request to go back in the shop. I love examining everything when it's torn apart.

http://www.nissaninfiniticlub....=7914

[DAEDALUS]

Well folks, it was bound to happen sooner or later. I have a bad injector; fortunately it's on the #1 cylinder and I have easy access to it. Took me an hour and a half to trouble-shoot, including getting the error codes from the ECU. Intermittent resistance shows 25 or 49 ohms. Seems the open circ is doubling the nominal resistance. (2*12=24, 2*24=48)I've taken the injector cap off, just wanted to see if there's any trick to pulling it out. I was planning to just pry it out with a screwdriver after bleeding the fuel rail's pressure. New injector and seals will be ordered from Scottsdale on Monday.The other injectors all ohm fine in the low 12's. Any thoughts or tips?

[Q451990]

Sounds like you've got it under control... They're really a pain to get out so the screwdriver method or a big pair of pliers should work. Other than that it's fairly simple - just be sure to lubricate the o-rings before putting it back in. A pinched o-ring can cause cause flooding and in very bad cases hydrolock!

I used vasoline, but some prefer di-electric grease. The new injector probably won't feel like it's going all the way back in, but after you put the cap on and tighten it down it'll seat correctly.

Heath

[yellow1342]

Hi Daedalus;

I've a 90 Q45 for a year from a friend with only 65K, it's been engine missed fire caused a little vibrating since I bought july 02. last week check light was on for a day and engine rocked badly loose power and gas milage was down to 15 per gl.

Check at dealer found out #6 & #8 injector was bad. Last night I tried to open #1 injector to find our what color code to order but after removed cap, I cannot pull it out (since #1 was not the defect one, I don't want to ruin it.

then I searched to you mentioned same situation, how did you pull it out? also how to release the fuel presure too?

thanks/phil

[DAEDALUS]

Phil, welcome to NICO! The color code should be on the head of the injector under the cap. Look for a colored dot. Mine were organge, but I've heard it may not matter anyway. Spray pattern matching or something to that effect. The injectors are squeezed into the fuel rail with a couple of o-rings, and this is what keeps them trapped. Friction only. To get them out you can pry a little with a screwdriver but be careful about marring the fuel rail under the cap. After I got the injector up a little I just grabbed it with a set of pliers and pulled straight up.

Releasing fuel pressure:http://www.nissaninfiniticlub....11308

[yellow1342]

Is the OEM Bosch ok? from expressautoparts.com selling 113 each, I saw you normally recommend to infinitipartsusa.com which listed 143 each? any comment?

Since I'll have to remove plenum so that I'll have to replace the gaskets and PCV valve as well?

Last question How to release the fuel pressure? where is fuel rail (which area?)

thanks/phil

[maxnix]

It's all in the posts. Might try a few more searches.