so, compression test should yield what numbers?
 

about where should i be for a compression test, and what do i do if 1 or more cylinders and low? i have yet to put on my new coils, and i'm thinking about doing this before hand.

I forgot the actual specs. 180 or so if I recall.

I'd expect lower, yet fairly even compession readings now. Generally a 15 percent variation between cylinders.

The FSM lists standard (nominal) compression at 185 PSI and minimum compression at 142 PSI.

thank you, so, below that it's a new block? or engine restore? heard good stuff about that.

Our engines generally don't have compression issues.

The the main issues are generally coil and injectors.

Do take compression readings. Also put the spark plugs in order. Then take close up photos of the electrodes.

Are you burning a significant amount of oil?

Spark plug electrodes in cylinders which burn oil will look dark and crusty. While those from a healthy cylinder will look clean and dry. The color will be greyish brown.

Mechanic in a can compound seldom works well in the long run.

Pull the plugs, take the compression readings, and report back.

By the way.... remove the fuse to the fuel pump first . Then run the car till it stalls.

Take compression readings whike the throttle is wide open. This is so the engine can breath enough air to show accurate readings.

spark plugs are new. no on the oil, just leaking a little through the timing cover. i heard about removing the fuel pump fuse. just that fuse? any oil flush product recommended? or just change the oil, thanks

My maxi been sitting in the garage for over a month now.. haven't touched it ever since I saw the strong smell of fuel and white smoke out of the exhaust. The battery is probably dead by now. I'm concerned if the engine is damaged, Cause alot of people say white smoke is not good.. hope to fix it soon. Yours too Max ride! hope to hear what fixes your problem.

Not sure what you're waiting for. It's the injector(s). Fix it already and enjoy your Max.

+1 yup.

Classic symptom of a failed injector.

no engine damage.

hate to say it guys, but my white smoke was a result of a bunch of problems. 02 sensors, plugs, vacuum leaks, running rich because of intake leaks. i'm doing the compression test next week josh, i hope i't doesn't yield any bad cylinders, rings could coated in carbon. i think you should do the same josh. don't let it sit. i replaced all of my injectors in the last year and i still had white smoke.

The engine had air leaks. The ecu compensates by adding additional gasoline to the mixture. Way more gas than it needs. Hence the white smoke.

right, thank you, plus, i have yet to replace the coils. i may or may not need or have to depending on compression test. their may be a leaking injector or a failing one, but i have no codes for that. i have always gotten a specific code for that, be it p0306, etc.

JVG, I wasn't talking about maxride's Maxima, I was talking about Josh's Max.

In Maxride's case, he has too many issues at once and needs to address them one by one. Plus too many inexperienced hands have been working on Maxride's car the past year.

ummmm, only one, me. lol i've had the help of a friend/mechanic who doesn't know my car very well but has worked on cars for years. he just likes to throw parts, but has run many tests on it to no avail. frustrating and annoying is all i can say.

He obviously does not diagnose and identify the actual issue. He just throws parts at a problem, hopng that one of them fixes the issue.

Our cars have certain known issues which we all know about.

He is not familiar with our ride. So I'm going to say that he does not know what he is doing.

Find another mechanic.

most places around here don't want to touch my car w/o going through all the bs i already have done to the max, plus i had a master tech at nissan 2 weeks ago pretty much confirm what we pretty much already ready knew. he's ran a few diagnostics on her and his scanner won't even read my car cause it's so old. but he has run some other tests on her and i had so many issues with maxy running rich and all he did what a lot of other garages would have done and just started replacing parts that threw codes and out of frustration i said go ahead. the car ran great after i left the garage but the next morning it was back to $hit.

Maybe, but don't rely on a "no DTC" situation to tell you you don't have an injector issue. These failures are made apparent more by the outward symptom than by the presence of a DTC ... don't get me wrong, that's not to say that they don't/won't/can't result in a stored code.

Nonetheless, if you've got all or some (and I don't recall if you do or you don't) of the classic injector failure symptoms (visible exhaust, rough engine operation, exhaust that smells of fuel, raw fuel drips from exhaust system) then the likelihood that you've got failing or failed injector is pretty high ... code or no code.

agree, but i don't have any gas smell at all. mostly exhaust smell and rough idle that's frustrating the crap outta me. i didn't rule out an injector cause that's just common mechanics 101, or wizardry right there. :p

A leaking injector will not always set a code.
Because the electrical portion is still ok.

You have been told what the likely issue is by experienced members of this forum.

Collectively we probaby know more about the common issues than most mechanics.

Yet you seem to want to argue with us.

only with you jvg, only with you. ;) i know if it's not the mechanical because i would smell gas, still, one can go bad. i am testing those goddamn things while i have it apart as well. if i unplug the injector, is it an obvious dip in the idle?? been awhile.

Face it.... the injectors will fail soon of they haven't already.

So you say you have things apart now. Does that mean that the upper intake manifold is off.

if so, do your self and your car a huge favor. Replace all three of the rear injectors while you have the opportunity.

i already replaced all 3 of the rear injectors earlier this year. intake manifold gaskets upper/lower are new as well as the rear valve cover gasket. fronts are new as well.

so, did a compression test and my mechanic did it while it was warm and we couldn't find the fuel relay to disconnect it so we just did the best we could. it looked real good, put all new coils on, plugs were black on the top. cleaned them off, put it back together, car started right up and ran good. that is until it warmed up. stalled at low throttle and buckled slightly under 40. anything over 40 it was ok. what it still causing this issue? fpr, clogged oil filter, clogged cat ( was running lean for a year ) i'm stumped, it does run better, but i want it to run normally, ideas, thoughts, place to find a new maxima???? :scratch:

You're not going to find a clean 4th gen like yours, especially your color and hopefully rust free these days. Just keep working at it.

obviously, i'm just sick of this $hit. passenger side is rusted and damaged in the rear. i just want the little fuker to run right. o, and josh, there was a 123,000 white 96 maxima that sold for 1,800.00 on ebay this morning, i almost bid on it.

If you are having trouble diagnosing it yourself, maybe have a professional shop take a look at it. Sure it may cost more but at least they can try to pinpoint what it is.

Damn wheres that blue max?? I'd buy it and swap out the grille to the SE grill match with paint and change to better rims.

So we have: p0300. Rough driving, stalling at idle, little power, white exhaust smoke, exhaust smoke smells like gas, forum members suggested injectors but no those are "new", replaced CPS, egr tube broken by mechanic, mechanic unplugged injectors (which changed nothing, hmmmm), cleaned TB, bought some coils, ran a halfarsed compression test, couldnt find fuel pump fuse, screw it I'm not continuing this convoluted list.

It's not often that I come here and tell someone they're a fool running in circles and contradicting themselves but, it is what it is. Both you and your "mechanic" need to take your hands off this car.

In one of your threads, you stated your exhaust smoke smells like gas, then later stated in that SAME thread that you don't smell any gas. You argue with anyone suggesting injector failure because your injectors were replaced recently, because how could new parts POSSIBLY be defective? I mean, your mechanic unplugged 2 of them and nothing changed, that's a telling sign right there. But let's keep firing that parts cannon! It must be nice to have deep pockets.

There are other possibilities, but they are less likely to be the cause of your problems. You never mentioned cleaning the egr, iacv, or maf. The ects can cause some of the symptoms you've described as well. However, the general consensus is that this is injector related, and you really should stop throwing random parts at this car and fix it properly, or hand it over to someone who will.

I agree with you. I said the same thing to JoshG and maxride41 in other threads a while back. I even shared a story with Josh explaining how I had injector issues, replaced all six injectors, and still had the same issues (white smoke etc), scratched my head, but quickly determined that 1 of the 6 injectors I received was a dud. Once I replaced it again, my issues went away and the Maxima has been running like a champ for the past several years. Unfortunately, my story has fallen on deaf ears and no one wants to revisit the possibility that their new injector(s) could still be the problem.

believe it or not, i have addressed the injectors, all new coils and have done multiple scans on the motor plus i took it to a friend who works at the local nissan ( master tech for 25 years) dealer and he pretty much summed up what i already knew. 2 vacuum leaks ( fixed ) and all new coils and the car started right up like new. still having an acceleration issue and the plugs were black when checked leading me to believe it's a fuel pressure issue, ( fuel pressure regulator ) and possibly a clogged cat. i have been listening to op's suggestion about injectors, i believe they are all fine. no gas smell, leaks or codes. i ain't going to fix it if it ain't broke. too much time and $$$$ spent doing things twice and i know those injectors are solid.

Ma​​​​​​xride.

as how many miles ago were the vacuum leaks fixed. Was this on the same set of plugs?

the vacuum leak would cause the ecu to enrich the fuel amount to compensate for the leak.

the fpr could indeed have a leak. A ruptured diaphram would admit excess gas.

i did the plugs before the leaks were fixed, i only knew about the one. didn't drive it more than a few miles, went to put the coils on and when we pulled the plugs they were coated powdered black. fixed the other leak and put the new coils on after cleaning off the plugs. started with no issues but still hesitated after warming up and stalled a couple of times at low throttle. from everything i've read the fpr seems a likely culprit, i might possibly have a blocked cat as well but if it is, i think it's a partial block at best. i also had black soot coming out of the exhaust after doing everything, but i think that was from sitting and running the car with the bad coils and leaks.

Maxride.

Did you lubricate the injector O rings before you installed the injectors?

Failure to do so can cause air leaks, and the same symptoms which you still have.

The ecu responds to air leaks by adding more gas.
Which would explain the black plugs.

no, i didn't put them on. i don't think my buddy bothered to, but don't quote me. i do remember unplugging the front injectors and one of them was acting a little weird. guess i'll have to check them all after going through all this i might as well. does unplugging them and having the engine rpm's dip a little the way they should react? rookie question i know

Of course the engine rpms would drop if one of the injectors is unplugged. The cylinder no longer contributes power. It's compression creates drag instead. You would experience the same thing if the coil lead was unplugged.

I'm saying that lubrication allows the rubber o rings to slip into the hole it's supposed to fit into.
Lack of lube would cause the rubber to distort or break. That in turn causes air leaks.

The ecu will make the mixture richer to compensate for the extra air. The excess gas will also get injected into cylinders which don't leak. That would cause the dark deposit on the plugs. The engine is running WAY rich.

The reason I wanted you to look at the electrodes is that the color tells us what is going on in each cylinder. Please Google : How to read spark plugs.

The solution is to get another set of seals for the injectors. You will also need a new uim gasket.

The problem is improper installation of perfectly good new parts.

I'm going to use a bit of sexual reference.... imagine what happens if a rubber coated item is shoved into a dry hole. The rubber breaks.

We all make mistakes from time to time.
This is a new be boo-boo. Live and learn.

Wow......just wow.

i've done a lot of research and understand what makes the car tick. but i don't fully understand why if the injectors don't throw a code and not leaking how they can still not be working other than maybe not firing properly because of some dirty fuel or a bad fpr etc.thanks for your input