New injectors, stalling, DANG, *video*

[paranoidjack]

So I installed new injectors from Deutschewerks last week. I should say, before doing so, I was experiencing this same problem but not as pronounced. The injectors DID fix a *rough* idle, because there was a broken one where fuel just dumped out. That's better.

However, the Engine Control is not operating properly. I have checked and rechecked all connections. My next recourse is to follow FSM, but unfortunately for these symptoms there are MANY MANY things to check.

I was hoping one of you here might recognize the issue and have a suggestion.

I've attached a video of the car starting for the first time in 5 days. I should add that trying to start the car when it is already warm is futile - it just dies, dies, and if you apply gas, dies faster.

I think it's a vacuum leak - unsure....maybe Fast Idle not actuating?

Sorry, after 45 seconds I thought I turned off the camera, so you get pocketview for a bit. Any suggestions? Or better yet anyone with a q that wants to swing by my house so I can compare them LOL?

http://www.youtube.com/watch?v=sX5XlMiw ... r_embedded

[goody90q45]

Any white smoke coming out the tailpipe when you can keep it running? Maybe an injector didn't get seated properly? You might check fuel pressure to make sure it's holding pressure when the engine shuts off and not bleeding off right away.

Also check the larger valve cover ventilation hoses that feed exhaust gas back to the intake tube in front of the MAF. I left the lower hose off after a plenum pull and the engine acted similarly. A loose hose or a split in one of the hose ends could cause the same problems. If you can keep the engine running try spraying around with a can of brake parts cleaner.

Is that the CEL on in the lower left of the instrument cluster? Any codes? How did the rear hose on the plenum at the IAC valve go back together? It's a tough one to line up and get seated. Take a look back there with a mirror and verify that both the 1" hoses are hooked up correctly.

The jumpy idle could also be a bad MAF sensor or more likely a loose and/or corroded connector. You know the procedure-clean...tighten...lube. Just for kicks try running the engine with the MAF unplugged and see if there's any change.

[paranoidjack]

Thanks Mike for the input. I'm going to look at it again tomorrow, and will check those suggestions. Exactly the feedback I was looking for, thank you.

[Q451990]

This is the first failure I've heard of on a '97+ Q45. What happened to your OEM injectors? If everything else checks out, I would definitely pull the rails, pressurize them, and look for leaks. Did you lubricate the o-rings when you installed them?

Heath

[paranoidjack]

Wow - the first one huh? Don't I feel privileged? Figures!

Well, it was a clear failure. About 25k ago I pulled plenum etc (my walkthrough) to replace KS's, at that point I noticed all of my pintle caps were bad and injectors looked crappy.

http://www.youtube.com/watch?v=plbvv77tKHk

Anyway, the car was exhibiting these exact issues (the ones I describe in the thread above) for the last 3 months. I had purchased a set of injectors from a junkyard, and then sent them to Deutschewerks for full rehab. At the time, my car WAS running more reliability (stayed running), but very rough, I could hear the cylinder missing, knew it was injectors, so went the Dwerks route.
I got them back 2 weeks ago and changed it all. I started the car, it stalled. Started it again, stalled. Started it a third time, it held idle, but not very well.

The injectors I removed were bad, as indicated by an oring that was so swelled in one, it had cracked the plastic housing and pushed down through the pintle caps. Really bad.

Although the car is exhibiting the stalling issue, when running, I can clearly hear it is running much better - just not staying running! Also, like I said, if the car is warmed up, and turned off, good luck getting it started. Very difficult.

The lights you saw were not CEL, they were the trac lights on because the rpm's were so low, I was activating lights. Although the CEL *is* on, it was off in the video. I'm going to run it again tomorrow for a few miles and see if I can get the CEL on, I cleared it and since the car hasn't run long enough to activate it again.

I don't think the rails or injectors are bad, they are FRESH from Dwerks a few weeks ago.

Heath, when you say lubricate the orings, are you talking about the orings seating to the rails, or the rubber washers that seat the rails to the runners? I personally didn't deal with any injector internals, as I provided them the rails w/injectors mounted, as they returned them.

[goody90q45]

I don't think the rails or injectors are bad, they are FRESH from Dwerks a few weeks ago.

Heath, when you say lubricate the orings, are you talking about the orings seating to the rails, or the rubber washers that seat the rails to the runners? I personally didn't deal with any injector internals, as I provided them the rails w/injectors mounted, as they returned them.

Heath is asking about the injector o-rings, not the rail o-rings.

Any white smoke out the tailpipe?

[paranoidjack]

Rail orings - no.

White smoke - nope. You talking about compression loss/head gasket/coolant?

[goody90q45]

No. Looking for unburnt fuel from a leaky injector o-ring.

[maxnix]

Jack, email me please.

[paranoidjack]

Brian please send me an email, I formatted my machine and don't have yours anymore.

[Lou92Q]

I just went through the same process with my '92. After replacing ALL of the fuel injectors, plugs, etc (including about $800.00 worth of plenum hoses), it ran better when it ran but it still had the intermittent problem where it wouldn't idle and woldn't start.

Replaced the MAF sensor and it runs like new.

[paranoidjack]

I put on a "new" maf recently - I cheaped out and bought an eBay one. It was so amazingly close to identical my fears subsided. I mean, IDENTICAL except for the nissan marking.

It was one just like this:

http://cgi.ebay.com/ebaymotors/New-MAF- ... ccessories

Anyone had a bad experience with one of these?

[mrpeeb240]

Jack, my Q has the same rough idle as yours but disappears once warmed up to temp. It has been happening since I purchased my Q last December, my belief is its caused by a slightly cracked of hose that warms up and seals or a dying MAF sensor. Unfortunately my Q was neglected by PO and also sat for a year in a driveway until I bought it for $1k. Id think you have either a vac leak or poor connection because of your stalling. I dont have much time to investigate my leak and still have not found a knowledgeable Infiniti mechanic so I two foot drive until temp comes up then idles smooth as butter
Brent
P.S maybe try starting it with a/c or defrost on and see if it stays running?

[paranoidjack]

LOU Nailed it - my chinese ebay MAF sensor is junk. Disconnected it and car runs a bit better - well, it starts and holds an idle without stalling. If I so much as tap the gas, the car stalls - should I be able to rev it to 2500, or should it stall right away? This may be a combination of issues, and I think I may have a vacuum mismatch somewhere, so if someone could verify for me how the car should should behave with MAF unplugged, that'd be great.

Thanks guys for the advice so far.

[maxnix]

Chinese MAF? For shame!

[paranoidjack]

Went to junkyard and grabbed Maxima MAF for $50 to test it out. Installed it, and bam ran beautifully!

Wow - went back outside, and car ran like it did previously - like crap! I changed nothing from my joyride back to the car.

I think one of the wires in the connector may be damaged. Looking at it, it appears to me that one of the blue wire liner inserts has been pulled out. I think it might be easiest to just get the connector from the junkyard and wire the 3 wires together. What a PITA, now I have to install my Chinese maf back, to get a refund on the connector while returning the old maf. Bah!

so...I think the chinese maf is OK!

[mrpeeb240]

When I unplugged my MAF car died instantly? I had rough cold idle before cleaning MAF sensor and harness and still have it after. Jack have you considered bad grounds?

Brent

[paranoidjack]

OK! For the first time in a looooong time, the car drove beautifully.

It was two things - both the MAF AND the connector! I tried all combinations of old maf/new connector, etc etc - it was both. That's what made it so difficult to diagnose - I didn't realize the connector was bad until I had the new MAF installed (and non functional).

Replaced MAF and pigtail from another Nissan and all is perfect.

[OwnerCS]

Congratulations and glad to see the Q running perfectly again.

Also, cool video with commercial/profesional sounding narration!

[paranoidjack]

Lol - thanks - professional quality editing (a minute of pocketcam, lol).

It's amazing to have it running well again - I have two more codes, EGR-C and intake timing control which re-illuminated, not sure why, will dig in this week more...