'94 Q doesn't like to go fast...

[nnicholas]

I am the somewhat proud new owner of a 94 Q45 with 175,000 miles on it. As soon as I got it I had an oil service, transmission power-flush, and had it checked for rough idle. The mechanic called me up and suggested that I invest an additional $2900 in injectors an a harness. He said two cylinders were showing weak but the compression was good. To make a long story short, I cleaned the MAF, the throttle body, new fuel filter, and a can of BG44K in a full tank of Chevron 93 octane. Now the car idles great, but if you really stick you foot into it, it starts missing like a plug is fouled and the check engine comes on. After it sits for a couple of hours it idles and runs well unless you run it really fast or aggressively and starts missing again. I'm no expert, but it would seem that if there were injector problems the symptoms would be continuous. Also, it has starting with a clicking-clanking sound intermittently in the dash.

I'd really appreciate some help. Thanks!

[Infinitiguy19]

Do you know why the light is on or what are the codes it shows?

See here if you don't know how: http://www.nicoclub.com/articles.php?id=60332

And I have to say that title of yours is the funniest I have seen.

Here is how to check the fuel injectors: http://q45.org/ohminjectors.html

Welcome to NICO

[nnicholas]

Thanks for the info. I'm a newbie with the Q and know just enough about cars in general to be dangerous, how do you remove the kick panel?

Thanks again!

[Infinitiguy19]

Feel around for a screw there is a little removable patch where a 10 MM bolt is, Sorry I don't know how to describe it.

If you feel better you can have the mechanic do it with his consult or similar if he has one, No need to remove the kick panel if you read the codes with a consult.

[96'er]

Welcome to the board!

First things first, down load a copy of the FSM, factory service manual, http://www.nicoclub.com/FSM/Q45/1994_Q45/ and become familar with the manual,ie where to find things.

Second, go to Auto Zone or similar parts store and have then connect an ODBII to the car and have them print off any and all codes. The FSM will explain what each code means and how to troubleshoot to resolve. If you are unsure, post the question on the forum. There are a number of very knowledgeable folks on the forum that can help.

Third, talk to whomever you purchased the vehicle from and find out the service history so that you can establish a baseline repair/service history and to determine things you are going to need to do immediately, mid-term and long-term to maintain this car.

Fourth, look over this technical page, http://www.nicoclub.com/subpag...shtml and Wes' Q45 page, http://www.q45.org/techinfo.html

Finally and most importantly, learn to use the search function to help narrow down a problem before you create a new thread. Chances are your question has been asked many times before and can be searched.

Good luck and again welcome aboard

[Infinitiguy19]

Great post unfortunately there code scanner works on 1996+ vehicles, 1995 and below vehicles each have there way of letting you read codes.

[maxnix]

One letter and one number for you. T 3

They have 3 shops in the Atlanta area. Take it to the one where Byron is the tech and let them do an assessment for you. You have done well so far, but you need a plan based on an expert's examination to proceed.

I assure you that a G50 does like going fast, too fast if you are not capable.

Welcome to NICO.

[Raxephon]

Second, go to Auto Zone or similar parts store and have then connect an ODBII to the car and have them print off any and all codes

Where's the univeral obdii connector on a '94?

I don't think you'll find one from the factory.(I have 2x'94 Q45's and neither one has OBDII)

To the original poster/thread starter, what do your injectors ohm out at?

I had the same symptoms in my green '94 and thought it was the MAF, but after swapping in a new MAF, (brand new OEM), the problem persisted.

Tested the injectors and got 11.5 ohms on 6 of them, but on #2 & #7 I got roughly 160ohms.

The check engine light was a fuel injector fault code.

And if you're a DIY kind of person, you should save your money & try to fix the problem yourself, if you're not a DIY kind of person then T3 is the best way to go.

[goody90q45]

.....Tested the injectors and got 11.5 ohms on 6 of them, but on #2 & #7 I got roughly 160ohms......

How come no one ever gets lucky and comes up with injectors #1 and #2 bad, or #1 and #8 bad, or #2 and #8 bad.......

[nnicholas]

First, thanks to everyone who answered this post. I really appreciate the warm welcome and the tips and advice.

Meanwhile, back at the ranch...The injectors all ohm out just below 14--number 1 is 14. This is good news...I think...Next stop is getting the codes read. I found the ECM but am too old and brittle too hunt for the diagnostic screw...I'll find someone who can decipher the codes and report back...Thanks again!!
Modified by nnicholas at 11:28 AM 2/8/2009

[maxnix]

You need to get the specialty cable and program for your laptop, or go to T-3.

Got FSM?

http://www.nicoclub.com/FSM/Q45/

[Raxephon]

.....found the ECM but am too old and brittle too hunt for the diagnostic screw...I'll find someone who can decipher the codes and report back...Thanks again!!

Diagnostic screw is on the opposite side that the harness plugs into.

[nnicholas]

I do have the FSM. Thanks.

[nnicholas]

I had the same symptoms in my green '94 and thought it was the MAF, but after swapping in a new MAF, (brand new OEM), the problem persisted.

Tested the injectors and got 11.5 ohms on 6 of them, but on #2 & #7 I got roughly 160ohms.

The check engine light was a fuel injector fault code.

What did you do about the fuel injector fault code?

[maxnix]

At 170 Ohms, they had to be replaced for the engine to run.

[Raxephon]

I replaced injectors 2 & 7, after that no more injector fault code.

Funny thing is these are the later series injectors, not the earlier pintle ones.

[Raxephon]

At 170 Ohms, they had to be replaced for the engine to run.

Incorrect.

They had to be replaced for the engine to run correctly without a stumble or jerking.

Especially at RPM's lower than 1500-2000.

[maxnix]

Incorrect.

They had to be replaced for the engine to run correctly without a stumble or jerking.

Especially at RPM's lower than 1500-2000.

What, you didn't want to save the bucks and drive the stumbling and jerking engine?

[Raxephon]

What, you didn't want to save the bucks and drive the stumbling and jerking engine?

Getting rid of useless/unnecessary plumbing is one thing, bad injectors can only be corrected by new injectors or a carb.

Side-feed injectors are crap and will continue to crap out over the coming years on all Q45's until someone comes up with a decent, cost effective, reliable top-feed conversion kit/solution.

Plus, I'm getting old. Small annoyances become big ones, if not remedied, when you get older.

[nnicholas]

I finally got the right cable and software from Blazt.

I also contacted T-3 about installing my new fuel pump and I am really impressed with them. They quoted me a really fair price to do the work and are happy to work with my parts (without warranty of course).

Back to the codes. It's throwing Code 34 Detonation sensor circuit. Is this a coil pack?

Thanks,

Nick

[maxnix]

KS, which are at the very bottom fo the valley of brittle hoses.

Better read up on under plenum hose job.

[nnicholas]

KS, which are at the very bottom fo the valley of brittle hoses.

Better read up on under plenum hose job.

Thanks for the response. Since I'm a newbie could you elaborate?

Again, thanks

[goody90q45]

Back to the codes. It's throwing Code 34 Detonation sensor circuit. Is this a coil pack?

At this point you'll want to measure the ohms resistance of the KS to determine if one or both are dead, or if the code is being thrown due to some other issue with the engine. It's easy to do with a voltmeter and won't take 5 minutes. You might as well check the injector resistance while you're there. The cluster of connectors can be found at the base of the plenum on the passenger side.

I finally got the right cable and software from Blazt.

You were able to pull the codes using the cable and laptop? What did Blazt send that worked? Different style cable chip?

[nnicholas]

The picture was really helpful. I had previously ohmed the injectors and they were around 13.5. I'll do the knock sensors next.

I ordered an OBD usb cable and software from Blazt. I received a link to download Nissan data scan. I downloaded v 1.53 beta and it automatically downloaded v 1.52 as well. The only problem was getting the software to look for the right port. Worked great. I think the software and cable pkg was $120.00.

T3 is doing my fuel pump tomorrow.

I really appreciate the advice.

[nnicholas]

Which pins on the ks harness do you test?

[goody90q45]

With the 6 pin KS connector oriented as shown in the pic, measure the bottom two pins (labeled X).