injectors 1990 Q

Post by **Qship4life** » Sun Feb 26, 2006 6:34 pm

Does anybody else have problems with injectors failing frequently in the 90 model?

Post by **maxnix** » Sun Feb 26, 2006 7:58 pm

Not unless you are in CA or don't maintain your fuel system.

The old single pintle are not as long lived as the later rotary disc, but it's not a great difference.

Read the posts by Q45tech.

Post by **lino** » Sun Feb 26, 2006 9:17 pm

My car is a 91 and I think mine are original. I really don't know how to tell if the injectors have failed other than reading that a common symptom is shaking at idle.

Post by **3rd Q** » Sun Feb 26, 2006 9:27 pm

Qship4,

Welcome! Good to see another Chicago area Q owner on the board.

I can tell you a little about failed injectors . Have replaced 31 of them between my 3 Qs (two '91s and '90) -and my 4th- a parts car I bought had 5 bad ones as well:( . May be replacing my 12th one on the '90 in 2 1/2 years I've owned it.

I've driven Qs for 11 years now and love the cars- but they eat injectors like candy! Most blame it on the gas here in Chicagoland- however all the other fuel injected cars I've owned here over the past 20 years (including other Nissan products) have had no- as in zero- failed injectors. So if you ask me, I chalk it up to a poorly designed injector for the early Qs.

I, and some others, will be trying a transplant of the '94-'96 injectors onto '90-'93 heads. Hopefully this will work since it seems that this design has fewer failures.

Dealers want $700 to replace the 1st one + another $200/per + another $50 labor/per to do additional ones- adds up quickly. Joe sells them for $140 each if you're doing your own.

If you are going to DIY it, Wes has a great write-up on q45.org with detailed instructions for removing the plenum. Or ask and some of us will be happy to give pointers.

Paul

BTW, met a new Q owner in the Home Depot parking lot last week. She had just bought a '91. Asked me about the cars since she had just found out her lumpy idle was due to - you guessed it- 2 bad injectors. Told her the same thing- great cars, but you gotta be willing to make sacrifices of time and money to feed the injector gods . She hadn't heard of the chain guide gods yet either.

Post by **Q45tech** » Mon Feb 27, 2006 12:06 am

I can tell you a little about failed injectors . Have replaced 31 of them between my 3 Qs (two '91s and '90) -and my 4th- a parts car I bought had 5 bad ones as well:( . May be replacing my 12th one on the '90 in 2 1/2 years I've owned it.

Compared to my 16 year old [305k] Q with no failures ever!

The gasoline you buy makes all the difference!

YouTube · Post by **Jesda** » Mon Feb 27, 2006 12:14 am

Nissan did not adequately prepare for US gasoline. Crap injectors, crap pump, crap everything. You have to be extra careful about what you fill.

Post by **maxnix** » Mon Feb 27, 2006 4:51 am

Jesda wrote:Nissan did not adequately prepare for US gasoline. Crap injectors, crap pump, crap everything. You have to be extra careful about what you fill.

Not true! They just didn't expect crap gas! They thought all gas was closer to JDM quality, not US near kerosene.

YouTube · Post by **Jesda** » Mon Feb 27, 2006 5:02 am

maxnix wrote:Not true! They just didn't expect crap gas! They thought all gas was closer to JDM quality, not US near kerosene.

I know, thats what I just said. By failing to meet expectations and demands of the US market, they screwed up, so they fixed it in 1994.

Post by **Qship4life** » Mon Feb 27, 2006 5:23 am

thanks for all the info. My Q has been in the family now since around 1995 and my dad was always putting injectors in that car. since i have owned it (may of 2004) i have had to replace six and now another one has failed. It is getting expensive so i was just wondering if anybody else had came up with a solution to the problem yet. How about adding injector cleaner to the fuel? Has anybody tried this?

Post by **Q45tech** » Mon Feb 27, 2006 5:45 am

"Nissan did not adequately prepare for US gasoline."

Which US gasoline impossible too look into a crystal ball and see the blends 10-15 years out!

Nissan issued a written warning to California CAB/ARB [1992] that the proposed changes would destroy their injectors and that future proposed changes in 1996 would adversley affect the new design to fix the 1st problem.

CAB supposed answer was great that will get the old 90-95 cars off the road sooner.

Nissan didn't make the injectors plus as far as I remember no/few injectors failed in the first 4-6 years of use [under 60,000 miles].

One must understand there are anticonsummer forces at work in local, state, EPA, US Dept of AG: that could care less how much you spend on the Automobile. In an effort to fight the upsizing of engines and force conversions away from old fashioned gasolines.

The refiners are caught in middle trying to ship the lowest cost product that kinda works as gasoline ------give or take 20%

http://www.lindertech.com/pattern_failures.htm

http://www.babcox.com/editorial/us/us01 ... s10325.htm

http://seattletimes.nwsource.c...n=rsshttp://64.233.179.104/search?q...cd=36

Here is an example of the converse bad gas only affected big 3:http://64.233.179.104/search?q...cd=72

http://64.233.179.104/search?q...cd=90h ... d/5172501/

Obviously some one [paid] persuaded Google/newspapers to remove direct links

Post by **maxnix** » Mon Feb 27, 2006 6:34 am

Qship4life wrote:How about adding injector cleaner to the fuel? Has anybody tried this?

Search on BG44K and BG Fuel Rail Flush.

Post by **DebbiQ** » Mon Feb 27, 2006 6:53 am

We have had our '92 about 5 years. We replaced three or four injectors in the first 3 years of ownership. Have had no injector failures since swithcing exclusively to Chevron gas, per suggestion on this board. We have heard that the local GM dealer recomends Chevron for the notoriously crappy GM injectors. We are in California. Just our experience YMMV.

Post by **3rd Q** » Mon Feb 27, 2006 8:37 am

Q45tech wrote:I can tell you a little about failed injectors . Have replaced 31 of them between my 3 Qs (two '91s and '90) -and my 4th- a parts car I bought had 5 bad ones as well:( . May be replacing my 12th one on the '90 in 2 1/2 years I've owned it.

Compared to my 16 year old [305k] Q with no failures ever!

The gasoline you buy makes all the difference!

Well, Dennis, we've had this conversation before. It certainly is not because I've been using cheapo crap gas- have never run a tank ever.lIf some of the country does not have a problem with the injectors, that's great. Sure doesn't help those who live where I do where it is a constant and never ending issue.

It's not an issue of the "quality" of gas. I still point to the fact that I've never replaced an injector in any other vehicle (including other Nissan products from the same era). My wife sure doesn't make a point to buy the best gas like I do- she puts in the cheap stuff- no failures in her vehicles ever.

Obviously, this is a sore point for me- over $5,000 spent on injectors-compounded by the fact that the Infiniti could give a **** about the issue.Have had numerous injectors fail within the 12/12 warranty and usually have to fight it all the way to Infiniti corporate to get it handled. It seems as though if you haven't paid the dealer to install them, they're not too interested in taking care of you.

BTW, just because I disagree with you on this issue, it doesn't mean that I doubt your experience or expertise. You know these cars better than anyone and I've benefited greatly from your knowledge. I mention this since you seemed to get a little offended last time we talked about the issue. I'm just stating my personal experience with injectors and I've had plenty.

Paul

PS- Maybe someone in the Southeast could sell me a tanker full of that good gas and I could park it out by the garage for my personal stock .

Post by **squeefoo** » Mon Feb 27, 2006 9:02 am

3rd Q wrote:[...]Paul

PS- Maybe someone in the Southeast could sell me a tanker full of that good gas and I could park it out by the garage for my personal stock .

...or one of you Guinea Pigs will hurry up and find if those '94 injectors work good or not. Tick tock I do my best work when it's cold out

YouTube · Post by **Jesda** » Mon Feb 27, 2006 10:08 am

Q45tech wrote:"Nissan did not adequately prepare for US gasoline."

Which US gasoline impossible too look into a crystal ball and see the blends 10-15 years out!

GM can make the injectors in a craptacular '85 Buick Century last 20 years, from cars made during their biggest cost cutting period. There's really no excuse here. We're eating through injectors like candy while Grandma's rusting beater is doing fine.

Whats sadly amusing is that current vehicles, like FX45s, are dealing with knocking and pinging in the western part of the US. Nissan continues to design fuel systems that are incompatible with the US market.

Post by **elwesso** » Mon Feb 27, 2006 10:33 am

I came across this article, and thought this would be a good time to read it.....

http://q45.spilky.com/gallery/v/18861388.pdf.html

Its only 4 pages and it has pictures!!!

Post by **66mgb** » Mon Feb 27, 2006 1:02 pm

I've used Chevron's Techron in my '87 BMW 325is and '92 Q45 every 4k with every oil change using Mobil1 oil and filter. They both run great and have never had injector problems. The BMW has 326k and the Q has 182k on the clock.

The Bimmer runs on the cheap gas, while I've always pumped premium into the Q.

I do think it's about time for a fuel filter, however! I bought the car w/ 60k on the clock and haven't changed the filter once.

Post by **Q45denver** » Fri Mar 03, 2006 10:53 pm

Just wanted to report progress or lack thereof. I have the 1994 fuel rails installed on the lower intake runners. Main step was to bore out the centers of the 90-93 spacers to insert the 94 spacers.

Post by **3rd Q** » Sat Mar 04, 2006 5:34 am

Werner,Great news!

Q45denver wrote:Just wanted to report progress or lack thereof. I have the 1994 fuel rails installed on the lower intake runners. Main step was to bore out the centers of the 90-93 spacers to insert the 94 spacers.

Did you fire it up yet?

I've been waylaid by installing a new alternator and A/C compressor, so I haven't made any progress on my rail swap. Keep us posted!Paul

Post by **Ezekial** » Sat Mar 04, 2006 3:59 pm

why don't you guys put a decent aftermarket ecu on it and change your injectors to whatever you want?

this also opens up lots of fun options like putting a billet 120 mm throttle body on and perhaps 1 or 2 turbo's or a supercharger, or stroker crank or nitrous or anything imaginable

Post by **elwesso** » Sat Mar 04, 2006 4:26 pm

Ezekial wrote:why don't you guys put a decent aftermarket ecu on it and change your injectors to whatever you want?

this also opens up lots of fun options like putting a billet 120 mm throttle body on and perhaps 1 or 2 turbo's or a supercharger, or stroker crank or nitrous or anything imaginable

because if you know how to reprogram the stock ECU (NICO ECU) it can do just as much... Still bring a good point...

Post by **Ezekial** » Sat Mar 04, 2006 5:28 pm

elwesso wrote:
because if you know how to reprogram the stock ECU (NICO ECU) it can do just as much... Still bring a good point...

yes but i can tune on the fly real time and go from running 7psi to 20psi in about 5 minutes

and i can change injectors to any size, any impedance, etc ... i can change tps, i dont have to run an air flow meter, etc

Post by **elwesso** » Sat Mar 04, 2006 5:32 pm

one could do that with the stock ECU if they had the technology.. assuming they had the know how to do that, they could certainly do that...

Not trying to start an argument, as i suppose its a good idea if your getting into really custom things, but for someone who is slapping a supercharger on a Q45 that would beoverkill IMO...

Post by **Ezekial** » Sat Mar 04, 2006 5:37 pm

elwesso wrote:one could do that with the stock ECU if they had the technology.. assuming they had the know how to do that, they could certainly do that...

Not trying to start an argument, as i suppose its a good idea if your getting into really custom things, but for someone who is slapping a supercharger on a Q45 that would beoverkill IMO...

hmmm i guess its just done differently over here

its common knowledge over here there is 2 ways to build a car

the proper way = aftermarket ecu FIRST then any modificationsthe dodgy way = fuel pressure reg or FCD or remap and then blow the engine up

But thats just how it works down undah mate

Post by **elwesso** » Sat Mar 04, 2006 6:09 pm

I agree... in the end the same result usually ensues, but IMO its just a more indirect and harder way to get to the said end result.

YouTube · Post by **Jesda** » Mon Mar 06, 2006 12:16 am

Ezekial wrote:why don't you guys put a decent aftermarket ecu on it and change your injectors to whatever you want?

Tell me who to write a check to.

Post by **DrewQ45** » Mon Mar 06, 2006 4:13 am

Nearing 200K and I've never touched an injector (knock on wood). My car has been fed a diet of NY and GA gas over it's lifetime.

Post by **Q45tech** » Mon Mar 06, 2006 5:36 am

Yes, the car escaped the North before the damage was done.

The magical exotic cleaning/healing properties of Southern Gasoline. Just like a SPA and usually a few cents cheaper to boot.

My theory is especially East of the Mississippi it has something to do with the Mason Dixon Line............revenge on Yankees...........have you ever met refinery workers.

Takes a Southern sense of humor to appreciate.

Post by **elwesso** » Mon Mar 06, 2006 8:13 am

maybe southern gas is tainted with southern comfort.....

Post by **Mr_Q45t** » Mon Mar 06, 2006 9:44 am

A couple of 2 oz squirts of some acetone per tank has helped me a lot. Arizona gas is crap, the highest octane is 91. Acetone cleans fuel lines, injectors, smooths idle and even dampened sound from my noisey fuel pump.

MPG testing in progress, but I am averaging 19.5 MPG on my last 3 acetone supplemented tanks. I was getting about 18 MPG with almost identical driving habits. Whether this is due to cleaner injectors or reduced surface tension of gasoline, is yet to be seen.

injectors 1990 Q

injectors 1990 Q

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Injectors

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