Bleach

I need some advice or suggestions on my ongoing battle with the Pulsar.

CA18DE - DOHC, coil packs, MAS. so no distributor or wires, and no adjustment on the Mas Airflow Sensor like an AFM has.

Here's the history:

Got the car this summer, PO said it never had an issue with emissions. No problems at all except for the transmission.

Well, fixed the rear engine mount which was the problem with the transmission. Also fixed the radiator fan that didn't work, engine had a stumble and rough idle, and it won't idle at all when cold. (cold start system?)

Warmed it up, drove through emissions
161,287 miles
Has rough idle, new spark plugs and that's all


Replaced coil packs, that fixed the rough idle and stumble
161, 391 miles
Idles good (once warm)


then I lost the key for about a month so the car sat

I replaced the oxygen sensor, back the ignition timing back and took it for a longer drive the morning of the test.
161, 479 miles


At least there are some noticable improvements this time. Still failing at idle and barely passing the CO % at cruise. What's the deal here?
Could it be as simple as needing a new cat or is it hard to say?

CanyonCarver

If it looks like it has the original cat, I would almost gaurantee that a new one will get you into spec. With 161+ k on the clock, you might also want to do a compression check to see if the numbers are within spec. There isn't much you can do if they're low unless you rebuild. A leak down test will tell you if it's rings or valves.

Lastly, it's safe to assume that all of the vacuum tubes and hoses are fresh and tight?

Bleach

First thing I did was a compression test to see if this car was even worth investing in. It was very good. All even and high numbers. forgot what it was exactly.

aaah, as for the hoses, this engine looks like a swap. the hoses and some emissions crap as just setting on top of the manifold. I did a lot of careful looking around. Nothing is unpluged and it all seems solid enough. I detect no vaccum leaks. I see one hose that is plugged but everthing else is hooked up correct. I can do some more inspection on the hoses, but the exhaust looks factory... but how can you really tell?
The cat unbolts so maybe I can remove it, and buy a weld-in and just use the factory ends on it so I can bolt it right back in place.
thanks for the help

CanyonCarver

You can check your cats with a infared thermometer. After the motor has been run for a while, like down the freeway, the temp should be up over 500 degrees.

NismoPick

I just had my BMW inspected & it failed the first time. I put new NGK plugs in, and ran a bottle of Seafoam w/ about 8 gallons of gas left in my tank. Took it back a couple days later... almost 0% emissions.

z-hag

i thot nox was cat .... but if they're already done,, then it must be the cat.

snwbrderphat540

wow... you have to pass emmissions on that car... IL eliminated OBD1 and earlier emmission testing.. only OBDII has to go... in there face.

WildmaN

No nox is the EGR valve, at least with mine. If your nox is too high, it usually indicates a bad EGR. But maybe it would be something else also.

Yeah Bleach, almost always, cars fail at friggin' idle. Seems to be a curse with me, for sure. And it looks like you are having a blast with it to. Anyway yeah I bet you replace the cat, it should bring down the CO. Also maybe the TPS, could be faulty. It has something to do with CO also. At least in my Z it does. Anyway hope that helps you out some. And good luck with the emissions.

CanyonCarver

They're not testing for Nox where Bleach is at.

SHADY280

fill yer tires up real good, like 50 psi, that helps big time, then add aboot 1 liter of methyl hydrate to the tank, that helps everything else. it isnt your timing cause both readings are close, if one was pass and one was fail and the pass was super high in one, id say timing, not the case here. id do a cat first, then run the tires and methyl.

Bleach

Tires?? I know these tires on the Pulsar are a little oversize. Like 5%. They're super bald and i worry they'll blow soon. I was gonna replace them with proper size tires after it passes emissions. You think putting the proper size (lower gearing) will help a little?
....although that would only make a difference if any at cruise, not at idle.

The TPS on this one is like a Z31 TPS. In fact, its very simular engine management to the Z32. Due to the fact that the off-idle throttle repsonse is very smooth and responsive I would believe the TPS has a good connection and there are no vaccum leaks. I did check the position of the TPS a while ago. It seemed good. I'll double-check that though. i wish you could open these things up and clean them. the box is help together like a 280ZX TPS.
still, this guy seems to get very good gas milage. I really want to drive it daily. My turbo Z has something wrong. It still runs great, but gets me only 17/18 mpg overall. A month ago I was getting 22/23 as I would expect.

thxone

EGR, PCV, Cat. Is there a smog pump on the car, if so is it working? How about the Charcoal Canister...does it smell like gas? Air filter, is it new? How is the MAP sensor? Make sure it is not burning oil while you are testing for emissions. Thats about all I have...little things first. Oh!! And if there is an air temp sensor, should be after the air filter...make sure it is clean.

SHADY280

i take out the air filter for emmisions, helps in certain situations

RodMoyes

Does it have an IAC???

And if so... Is it working?

Bleach

I dont' think it has an Immunization Action Coalition... but I'll check tonight

RodMoyes

Idle
Air
Controller

Bleach

It has one that looks simular to other Nissan IACs. No change when I unplug the connection on the end of it. Maybe its frozen closed.

I also see no idle adjuster on this engine except for the adjustment on the throttle cable itself.

RodMoyes

... Hmmm

That sounds interesting...


Maybe?






Rod.

Bleach

I removed the air filter and ran a tank of gas through it with injector cleaner. Then I added some special stuff that Shady suggested.

It got a lot better, but still failed one test at idle!

numbers from last test were: [ 278 ] - [ 3.28 ]

NismoPick

Maybe add more of the "special stuff" ? Does it use a MAF or AFM? Can you adjust the timing?

Bleach

it is a MAF and I already adjusted the timing. Previous owner had it advanced a lot. I brought it back to spec.

The special stuff was water seperator/fuel anti freeze. methyl hydrate. I added 24oz to about 2 gallons of gas. That's pretty high percentage. A bit more than Shady suggested. I suppose I could try another $15 test and another 6 bottles ($12) of special stuff.

so this Everclear stuff is actually alcohol and not a real fuel additive? weird... you ran that in yer BMW

snwbrderphat540

everclear? isnt that a drinking alcohol? cuase ive drank it on 2 spereate occasions.. one witha more spectacular out come the other... more of a fun out come... aka jumoing off a roof into a pool

NismoPick

no... I've never actually tried everclear. One of my friends' dad works for the emissions division of the DMV & he's always saying "throw in a bottle of everclear & it will pass w/ flying colors." I used Seafoam Fuel Treatment on my BMW last fall. It was just over the limit & failed. Threw in some Seafoam with 1/8 tank left (burned that tank mixture) & NGK plugs... passed w/ almost zero emissions.

snwbrderphat540

everclear. .. the drinking alcohol... really potenet.. and alcohol burns cleaner... it will work.. but your car will run like ***.

SHADY280

if its failing at idle, just back the timing up some more, aboot 2 degrees. i add 1 liter (whatever) to my whole tank of 30 liters. so 30:1 mix. anything more is alright too, just dont get it really high and it can cause some problems. remove the air filter to lean out the mixture, that will also help. raise idle to 1000, no matter what it takes, get it there. adjust the cable, or the tb set screw. all that will signifigantly increase the ability to pass. but like drinking, all in moderation.