Surgine Engine Problem

[AlabamaDan]

Hi guys! It's been a while since I've posted, I've been swamped at work for the last year with this hugh project. I need some help.

I've still got my 94 Infiniti Q45 with 130,000 miles on it. I drive it to an from work mainly in stop and go traffic. Rarely do I drive it over 50 mph. (I know Dennis is about to say that I need to run in WOT more often, and he's right.)

My problem now is that the engine is not running smoothly. Sitting at a red light the engine RPMs will drop to 250 then surge up to 1000, then back to 250....

It doesn't do this 100% of the time, but it appears to be getting more frequent.

It will also do this driving down the road too, not just at an idle.

I'd like to carry it to T3, but with them not being open on the weekend it's a scheduling nightmare. Also, right now I'm afraid it wouldn't make the trip from Birmingham to Atlanta.

HELP!

Modified by dannymchale at 8:53 AM 9/16/2005
Modified by dannymchale at 8:53 AM 9/16/2005

[qship96]

check maf and connector,also throttle position sensor.

[Q451990]

That definately sounds like a MAF or CAS connection. The surging from barely running to 1000RPM is the car going into "limp" mode for some reason. In my case it was a failing MAF.

Heath

[Aus94Q45]

Check the MAF Crazy post above -- sound familiar?

[maxnix]

Bah, humbug! What do these guys know?

Take it out on the highway, best with some BG44K in the tank and do some WOT runs!

Then check your MAF connection.

[AlabamaDan]

Thanks guys. Sounds like y'all are saying to start with the MAF and it's connections. Now all I've gotta do is educate myself on MAFs!

That definately sounds like a MAF or CAS connection...

What's CAS?

[DAEDALUS]

Crank angle sensor. It's the component in front of the exhaust cam on the driver's side head.

[AlabamaDan]

Ok guys, I'm gonna try and look at my car this weekend. I've been out of town, so it was just parked.

I have driven all that cheap gas out of it and it's on a new tank of premium.

The Q's still surging really bad at an idle almost to the point of going dead. I don't notice it when I'm accelerating, but it might still be there.

I was looking under the hood last night and did hear a "hissing" noise. It sounds like a vaccumn leak around the top of the engine, but I couldn't find anything. That noice does continue even at higher RPMs, but the noise of the engine covers it. Think these two may be connected?

Someone said earlier my problem could be the MAF. What do I need to do about it?

I really appreciate any help and advice. I've had this car for about 3 years and it has 134,000 miles on it. This is the first trouble it's given me.

[AlabamaDan]

Ok, I've been reading and this is a common problem it seems. I found this wonderful procedure that I'll try this weekend. Hopefully this fixes it and it's not some of these other injector, fuel pump, etc. problems I've read about.

http://www.q45.org/maf.html

Thanks for the q45 site Wes!

[q45tech2]

Hiss.....................did you check the "female anatomy" [a name not used in mixed company] hose?

Won't make it?Don't know how many lights you have in Birmingham but T3 is only 1 light from Alabama state line [I20>I285 exit 15 light then 100 feet]........so if you can get it on interstate.

[AlabamaDan]

but T3 is only 1 light from Alabama state line [I20>I285 exit 15 light then 100 feet]........so if you can get it on interstate.

I've been to T3 a couple of times when I lived in Atlanta. Y'all did a great job on my J30, then I wrecked it. Actually someone helped me I was just sitting there.

Y'all also gave me a laundry list of things for this Q45 when I bought it, but I didn't have the money and they all sounded like they could wait. But I would like to do some work. Could y'all accomidate me to work on a weekend?

BTW, what's the difference btn Q45tech and Q45tech2?

Oh, and back on the subject at hand, can you be more specific about this hose?[

[maxnix]

Dennis? Is that you? Welcome back! How was the wilderness?

[AlabamaDan]

Well I changed my oil today in the Q and cleaned the MAF according to the inx on http://www.q45.org. It was a little rough changing that oil filter but I got it. Cleaning the MAF was a breeze. I even did the little gel thing on the connector. But, it didn't change a thing. I guess it didn't hurt anything.

Now that hissing sound is bothering me and I suspect that may be the issue? But what is it? It's coming from around the right side of the plenum. I hope it isn't something underneath the plenum. I'm a long way from T3 and they're only open on the weekdays right?

While I was playing around under the hood today, I noticed that my fan has all sorts of cracks on it, for that I'll start another thread.

Help.

If a moderator reads this, could you please fix my thread title to read, "Surging Engine Problem - MAF?"

[AlabamaDan]

Ugh! It's actually worse than it was. Now it's pretty consistent with the crazy idling and it actualy goes dead when I'm stopped at a traffic light.

[areznik]

Hey Danny,

I have experienced the same "hissing" sound that you are describing. There are thing hoses that attach to egr and egr soleniod, they are maybe 1/4 inch thick. Under day light check all of them and make that there are no cracks or that non of them cut off. It actually happened in my case and it was hard to see it but I follow the hose with the fingures and found the problem. Its a quick fix and you can find these hoses at AutoZone. There should be no "hissing" sound at all. At least after I replaced all my hoses my engine is "hissing"less . Back that "hissing" sound, I had idle jumping problem as well and replacing the torn hose resolved it.

Good Luck!

Andre

[AlabamaDan]

I've been looking for that #@*& air leak off and on for weeks and just can't find it. I'm pretty sure that's the problem with my idle and it's driving me crazy. Where exactly is te EGR and EGR Solenoid?