CandiMan

iTrader: (1)

After 18yrs of ownership my auto VE has recently started to exhibit the lower engine power phenomenon. There are been countless threads on this issue, ranging from coolant temp sensor, knock sensor, spark plugs, cam/crank angle sensor, power transistor, etc. etc. etc.

Some background, 12yrs ago I advance my ignition timing from 15* to 20* and it has been that way ever since. Fuel filters and spark plugs are changed regularly. I've changed a couple injectors and all three of my front ignition coils have cracked and it was resolved with simple electrical tape. The engine has about 202,000 miles. EDIT: I also forget to mention there has been no engine codes stored in memory

It all started a couple weeks ago, with no prior symptoms, I went to start the engine in the morning and it cranked longer than normal before starting. I knew that was odd because that has never happen before.

As the days went by, it still exhibited long cranking, and when the engine did start, it would stumble for a few seconds and eventually smooth out. It doesn't matter if the engine is cold or at operating temp, it will crank excessive and stumble after the engine is running.

I've tried the knock sensor by-pass, new plugs, new coolant temp sensor, a different used TPS while making sure the TPS adjustment was correct, returned the timing back to stock at 15* and nothing. The engine still cranks excessive, stumbles when started and generally lack of engine power while driving. It feels like I have a parachute attached to the car. It doesn't drive as fluent as I'm used to, it doesn't miss fire while driving. It just feels low on power.

The engine idles smooth in gear, at a light, in neutral, AC on/off, it doesn't matter, and it idles well. Granted I have not ohmed the injectors but it doesn't feel like a injector issue

My question, have we determine a root cause for this issue with the VE's or is it still a crap shoot? From what I've notice it's hard to determine is this issue is fuel or ignition related. This weekend I'm planning on getting a cam/crank angle sensor and power transistor from the salvage yard to see if that helps.

DanNY

iTrader: (14)

my guess is coil(s)...but to really determine you'll need to pull the plugs to see. if they are wet then you have no spark.

the stumble after start is normal since during cranking fuel will spray. crank for a little longer and you'll get a slight flooding situation where it will clear up after a few revolutions.

a misfire wont be detected if its just not firing. also with one dead coil your idle should be "ok" but under load it's going to feel like you lost some power.

CandiMan

iTrader: (1)

When I say it's cranking longer than normal, I mean it has never done that in the past. Even when I've changed the injectors in the past after depressurized the fuel rail, it has started faster than what it's doing now.

But you have brought up a good point, what do the plugs look like when it's cranking excessive. What I'll try is, one day when it cranking excessive, I'll stop the cranking right before the engine starts, pull the plugs and examine.

As I'm thinking about it, another option is spraying starter fluid in the intake tube then crank the engine and see it something different happens.

Doing both of those will tell me if it's fuel or ignition related

Thanks

NSMO240

iTrader: (5)

this may or may not help but if a crank sensor goes bad on the 2.5 altimas it takes a terribly long time to start, will crank forever.

also, i have seen start signal fuses blow which causes extended cranking

DanNY

iTrader: (14)

unplug each coil while it's running...if it dies/studder then you know it's a good coil. if nothing happens you have a dead coil.

NSMO240

iTrader: (5)

After doing this if a certain cylinder is dead, I would swap the coil to a different cylinder and rule out that it could also be an injector or low compression.

CandiMan

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Keep in mind it's running smooth at idle all the time. I'm familiar when this engine has a miss due to injector and/or ignition coil. I've done the ignition coil disconnect in a effort to find which cylinder is missing. This time, there's isn't a miss. The issue is not while it's idling, it's when the engine is cranking/starting and while driving.

NSMO240

iTrader: (5)

Just recently my moms altima SE-R had a bad cam sensor it had a slightly rougher idle than normal and acceleration wasnt as smooth, the only time she ever had a real issue was when she was driving for an extended period on the freeway, then when She would decelerate when coming off the freeway it would basically act like it died for a split second, it took 4 instances to turn on a light.

Have you driven this a long period recently?

CandiMan

iTrader: (1)

Here's an update

Yesterday I went to the salvage yard and pick up a power transistor and cam/crank angle sensor. I removed my PT and installed the salvage yard PT. Went for a quick road test around the neighborhood and can tell a noticeable improvement. My car has 203,000 miles and the salvage yard car had 167,000 miles. I know my PT is original so I'm going to assume the salvage yard car also had it's original PT.

I'm planning on taking my car on out of town for the next 5 days. Before I get too happy, I want to put some mileage on the engine to see how it feels. The quick test around the neighborhood really doesn't tell me anything, but I'm being optimistic.

NSMO240

iTrader: (5)

That's great! I forgot the older maximas still had that, a buddy had a turbo sr20 that the transistor was going out and when he was at high rpm in boost it would sputter really bad, and that was a tough one to figure out

CandiMan

iTrader: (1)

I just did a 150 mile road trip this morning and the engine felt better. This morning when I started the engine, it fired right up. As soon as the starter engaged, the engine started. I'm not calling victory yet until I start the engine a few times, cold, engine, hot engine, etc. How the engine starts will be the true test.

If the power transistor was the problem, I can't wait to bump the timing back to 20* degrees

shiloh51933

iTrader: (5)

I had same issue with the PT and copped one from somebody on this forum, mine had a crack in the body.

James92SE

iTrader: (31)

CandiMan, what's your final verdict on this?

CandiMan

iTrader: (1)

Okay, hold on to your jock strap, I'll make it short and brief. When I replaced the power transistor it did make the engine feel a lot better. It didn't feel like I was driving with a parachute attach to the car. But, the excessive cranking condition still continued.

So I tried a different cam/crank angle sensor and it didn't change anything. The engine still felt good, but it still had an excessive cranking condition.

At this point I decided to break out the FSM (yeah, go figure) and I came across the section for checking the ignition coil. The only test for checking the ignition coil is ohming it out. The spec calls for .8 ohms and 5 of my coils ohm 1.1 and the 6th one ohm .2

At this point I'm suspecting my excessive crank was due to that one cylinder not igniting and dumping raw fuel in the cylinder causing a "flooding" condition because every time it would start after excessive cranking, it would stumble for a few seconds and I would smell raw fuel from the exhaust.

Out of **** and giggles, I decided to disconnect the injector on that cylinder with the low ohm reading and drive around for a couple of days like that. And every time I started the engine (with the injector disconnected) it would start ever single time, no excessive cranking and no raw fuel smell. It didn't matter if the engine was hot, warm or cold. The results were the same. Now granted when the engine did start it had a notice engine miss.

So it appeared I may have had two issues. A bad power transistor and a bad ignition coil. I just sourced out a used coil but it's in the mail.

Will report after changing the ignition coil

CandiMan

iTrader: (1)

Update,
My used ignition coil came in yesterday, so I just installed it on my lunch break. After I drive it for a few days, I'll update and let you know what's happening.

CandiMan

iTrader: (1)

Oh well, I just typed a elaborate update but it didn't post. So I'll give the cliff notes

Changing the ignition coil didn't help the excessive cranking time. It was a bad injector.

James92SE

iTrader: (31)

Did the injector Ohm out bad? Or how did you diagnose it?

My black VE that I just started driving again after nearly two years of slowly overhauling it is suffering from long cranking and intermittent really dead spots in the power band. Particularly in the ~2k range when accelerating around town. It'll feel really dead in between gear shifts in the 1.5k to 2k range and then suddenly feel "right" at about 2k. It almost feels as if the timing is severely retarded between 1500 and 2k and then at 2k it's advanced properly. If I advance the timing it mostly fixes it but then there are still slightly noticeable dead spots in the band on moderate acceleration but just not as pronounced. And the long cranking is still there with the advanced timing but just not AS long. Prior to parking the car two years ago to start the overhaul, this car actually started inordinately FAST. It would fire up literally on half a crank. As soon as you'd turn the key the engine would be running.

Now some back story - car has new (literally brand new, not remans) injectors, new coil packs (again brand new), new NGK factory spec plugs, new coolant temp sensor, new OEM knock sensor and knock sensor harness, new fuel pressure regulator, new fuel filter, all new fuel rubber lines, etc. Not relevant to this thread but I also have all new struts, bushings, seals/gaskets, steering rack, ps pump, even rebuilt calipers, new tires, new OEM clutch slave cylinder, virtually everything overhauled on this car that I can other than an actual engine rebuild. I want this car to be minty stock and good for another 20 years.

Anyway, the most concerning thing is that the car stranded me last weekend in the middle of the day in 100 degree heat on my way back from Target with a car full of groceries. Out of the blue, accelerating from a stop light it suddenly felt as if I were trying to accelerate from a stop in 4th or 5th gear (i.e., nooooo power and had to really really give it a lot of gas to even get moving). It revved fine in neutral albeit sounded labored but in gear could barely even get going to a roll and thankfully I was able to coast into a turn lane. The car was idling albeit rough and then died after about 2 minutes of idling in the turn lane. After it died I left it off for a few minutes to call my brother to come tow me home then for ****s and giggles decided to start it back up and it started and drove home fine but a little bit rough.

After it stranded me last weekend and reading your thread here I decided to just bite the bullet and bought a brand new CPS and brand new power transistor (Dorman units). I put those on which I hoped would solve the long cranking and/or the dead spot in the power band but they have had no effect on it.

I also bought a new TPS but haven't put it on yet as I'm waiting for my new multimeter to arrive.

Once I put the new TPS on and if that still doesn't fix it I have NO clue what possibly to look at now. I'm sure hoping the TPS is the culprit on the "dead spots" on the power band. I haven't heard of that being a common VE issue but I know in other cars it can give a "jerky" feeling in the power band (which I may just interpret as a "dead" spot) and other sensations of lack of power and/or the gas pedal not feeling "connected" to the engine.

Once that is on, this will be a pretty much brand new VE at that point. These issues aren't what I expected after two years and thousands of dollars overhauling this car

CandiMan

iTrader: (1)

For me, the excessive cranking issue started first before the low engine power. Since the starting issue only happened with a hot engine, the first thing I changed was the CTS. It did not help. After couple I changed the plugs, it did not help.

I can't remember the exact time frame, but when the low power issue started, I paid more attention to that than the starting. Sometimes the lower power issue felt exactly how all others have said. It felt like there was a bad spot in the TPS, but if you push the pedal more, it would occasionally "burst" through this bad spot. So I returned the timing to stock (it was at 20* for many years) it didn't help. I tested, adjusted and changed the TPS, it didn't help.

At this point I started to focus on the PS and crank/cam angle sensor. For me, the PS "felt" like it corrected the lower power issue. It stop feeling like I was driving with a parachute. But it did not correct the excessive cranking issue.

Then I decided to change the crank/cam sensor and nothing, power still felt good but excessive cranking still continued.

That's when I broke out the FSM and determine one of the ignition coil was ohming out of spec. Got a different coil that ohm within spec and nothing. Excessive cranking still exhited and power still felt good.

For the past 3 months I've been working out of town Mon-Fri and go home on the weekends. I usually drive (150 miles one way) to work early Monday morning so I would fill the gas tank on Sunday night in preperation for Monday morning.

This past Sunday night (9pm) I was leaving the gas station and there was a noticeable engine miss. At this point I'm like mother father, you have to be kidding me. After getting home, I started disconnecting and swapping ignition coils like crazy to determine which cylinder and if it's a coil or injector.

Luckily it was a injector in left bank, and surprisnghly, it was the same cylinder I thought had a bad coil. I verified it with my ohm meter and it was out of spec. I had a couple spare injectors, so 10 minutes later the injector was changed.

And btw, like most inventions that was invented, I accidentally figure out a way to help assist the injector out the rail. In a hast to change the injector, I forgot to depressurize the fuel rail. When I twisted the injector with my pliers to break the seal, as soon as I pulled, it poped right out and sprayed me. Like you guts, I've faught/struggle with removing injectors in the past. So I figured, that extra 40-50psi pushing up on the injector while I'm pulling probably help. So the next time I'm will do the same thing, instead place a towel over the pliers to minimize the spray. I would also advice, after everthing is back together, remove the plug for that cylinder, disable the ignition and crank the engine for a few seconds. This will push out any excessive gas that may have got into the cylinder

So it's been three days since I changed the injector. I'm not calling victory but the excessive starting issue has not returned. We will see......

The forum did it to me again. After typing this reply and hitting the submit button, it asked me to log in which I already have done. So this time, I copied my reply before hitting submit. And sure enough, it ask me to log in after hitting submit. So I loged in again, paste my reply and there you go. Does the forum time you out if it see no actively?

londonflu

James, WTF you too? Thought I'd make a late night/early morning run to the store today, then on the way back about 1 block from my place, I started getting a hesitation and loss of power, so I turned off everything since I just had the 2nd alternator replaced again just last week (first one was defective), thinking it was related, turned off headlights, stereo to see if it was a power draining issue. Still hesitated pulled into my parking spot and turned the ignition off. waited a minute or two and then tried to restart, it took two cranks before it finally started. It hasn't been 5k miles since I did the injectors, knock sensor, coil packs. It was dark out so didn't bother to pop the hood but I did notice white smoke coming from tail pipe, and a strange smell, sort of rubberish. First thing I though of is me cat must've went out?

dwapenyi

iTrader: (3)

Long cranking on VQ motors is usually a symptom of a tired and worn out FPR. If your engines have it too, I would consider replacing it.

CandiMan

iTrader: (1)

That's one thing I forgot to mention. I have a fuel pressure gauge between the filter and fuel rail. Every now and then I would turn on the ignition to prime the system, pop the hood to look at the pressure, then crank the engine to see what happen. I did that many times when starting a cold, warm or hot engine. The pressure was always the same (55psi - I can't remember the exact number) and I would still get excessive cranking at times.

I also forgot to mention, somewhere along the line I changed the fuel filter in an effort to correct the excessive cranking. Fuel filter did not help.

londonflu

Mine is dumping fuel somewhere and it's coming out of my exhaust! HELP!

CandiMan

iTrader: (1)

So far I've made it half way through the week with no excessive cranking. I'm almost ready to declare victory due to a bad injector. After a week, my plan is to put back my original PT to see what happens. And maybe my original crank/cam sensor to see what happens

James, I know you have new (not rebuilt) injectors. I'm curious, have you actually ohmed them to see what they currently are?

James92SE

iTrader: (31)

Candiman, I have not ohmed the injectors, but my new Fluke 117 came in so I'll do that at some point this weekend. I would be shocked and pissed if one tests out bad. I also plan to put in the new TPS at some point this weekend.

The strange thing with my diveability issues is that the car passed emissions with FLYING colors. Not even remotely close to any of the thresholds. So I would think all things fuel/ignition related would be spot-on to pass emissions so well. Nearly without fail all of my VE's over the past 15 years of owning them have struggled with emissions and probably 3/4 of the time I fail the first test and have to screw around on it and re-test. But not this time with all my new stuff.

Since I have my back seat out anyway right now, I may pull the fuel pump tomorrow and have a look at the assembly on the off-chance there's some sludge or gunk build up on/around it from largely sitting for so long. I do have a new in box fuel pump I bought a couple years ago on Rock Auto close-out just to have for a future spare. If my injectors ohm out fine, and the TPS does not fix it I may swap that new fuel pump in just to see if it makes any difference.


You know, I had something similar happen to me after I finished my 5 speed and JDM VE swap in my blue VE (now my turbo car). I had a lot of driveability issues with it in the beginning which turned out to be a fake eBay "OEM" knock sensor. I bypassed the knock sensor and it cured all my problems. Anyway, after that, all was well for weeks/months but suddenly one time on a 60-70 mile round trip picking a friend up to the airport, the car started running HORRIBLY and developed this really really strange smell. I could have sworn I made a thread about it back when this happened but I can't find it now - I don't remember exactly how I would describe the smell but I want to say it was rubberish and it was definitely unlike any car smell I'd ever smelled before. I thought for sure something was majorly wrong and like I said it was running horribly. I didn't have any smoke though. I limped it home and parked it for a day or two and it never once did it again and was all fine after that.

londonflu

You know, I had something similar happen to me after I finished my 5 speed and JDM VE swap in my blue VE (now my turbo car). I had a lot of driveability issues with it in the beginning which turned out to be a fake eBay "OEM" knock sensor. I bypassed the knock sensor and it cured all my problems. Anyway, after that, all was well for weeks/months but suddenly one time on a 60-70 mile round trip picking a friend up to the airport, the car started running HORRIBLY and developed this really really strange smell. I could have sworn I made a thread about it back when this happened but I can't find it now - I don't remember exactly how I would describe the smell but I want to say it was rubberish and it was definitely unlike any car smell I'd ever smelled before. I thought for sure something was majorly wrong and like I said it was running horribly. I didn't have any smoke though. I limped it home and parked it for a day or two and it never once did it again and was all fine after that. [/QUOTE]

Seemingly out of the blue, I have more that one issue James. I did purchase a cheap knock-sensor from ebay, so that has to go; and this time I will order and wait for the harness as well. it was back-ordered last time.

But even before I had those replaced, it never drove this bad, complete loss of power, with fuel fumed smoke from tailpipe, it was only 6K miles ago, since doing the injectors/knock sensor. What could be sending bad readings to the ECU to make it dump all that fuel? And has this fuel caused my CAT to burn up?

CandiMan

iTrader: (1)

James, just to confirm. The issue you're having is excessive cranking and intermittent low power, or just one of the two?

londonflu

Both James, but all of a sudden. But more like complete loss of power.

James92SE

iTrader: (31)

Both excessive cranking and intermittent low power.

I will point out that the low power is something DIFFERENT than the typical bad knock sensor low power, which in my experience I would describe as you said above about a parachute being attached to the car across most of the power band.

My current situation will ONLY have sudden low power in a certain RPM range. It genuinely feels like the timing is about 10 degrees between 1.5-2k. I can hold steady pressure on the pedal during moderate acceleration and as soon as it gets out of it's slump (i.e. reaches a bit above 2k RPM) it will surge forward as if it's been "unleashed" suddenly.

This sensation is what's making me HOPE it's the TPS

London - make sure your timing is at 15 degrees, and make sure to have some 91+ octane in the car and go get the 470k ohm resistor from Radio Shack and stick it in your knock sensor harness then drive it around and see how or if it changes your symptoms. That will instantly show you what effect, if any, the fake knock sensor is having on your current situation. But it sure FUBAR'd my car. The eBay seller I bought my "OEM" knock sensor from was deutschepartsusa

https://maxima.org/forums/dealership...ml#post8240574

londonflu

No more dumping fuel or excessive cranking. One of my injectors went out after just 6k miles. DO NOT BUY VENOM OR PYTHON INJECTORS FROM NOPI or anywhere else. I replaced with GP Sorensen from Autozone, but are at least it's brand new.

Also replaced 02 sensor, with NTK one made by NGK.

I'm going to have to redo the entire job over again eventially including the FAKE KNOCK SENSOR FROM ebay eseller956 although his feedback is a 99.7 rating; he sales nothing but FAKES. BEWARE THEY ARE ALL OVER THE PLACE NOW INCLUDING AMAZON.

londonflu

James, I would still have to pull the IM to get to the harness though right?

dwapenyi

iTrader: (3)

I would still change the FPR, especially if it's never been changed before. Bear in mind that the readings you are taking are in a static, not dynamic, situation. It's like a dirty air filter or old oil filter. They all still work and do their job, but not at their best.

James92SE

iTrader: (31)

To remove and replace the knock sensor harness you have to remove the upper and lower IM, yes. To do the resistor trick, no. On the resistor just unplug the KS harness right there on the thermostat housing and place the resistor in the ECU side of the harness

James92SE

iTrader: (31)

Well I played around with the TPS that was already on there and from best I can tell it tests out fine. I also tested all the injectors and all ohm out between 11.6 and 12. I decided then to pull the pump to inspect it and the tank and I find this. This pic was taken after I had already wiped a bunch of the sandy/clay-like material off.

Pretty annoying. The tank is covered in it too. I'm a bit surprised since even though this car has been sitting for two years, I did somewhat regularly start it up and let it run in the driveway and also would add fresh gas to it to "dilute" any bad stuff in there. So I guess now it's new tank and fuel pump sock time.

londonflu

Thx, I will try this the next time if and when it happens James m8! I've been driving her hard all weekend and no apparent problems. So I really can't count out the KS yet, since what I did changing the injector and O2 sensor did the trick, she's running a lot smoother now then ever.

Did you guy's check your vacuum hose on the firewall, I had a crack on mine one time and it caused a hard to crank issue in the past BTW
.

londonflu

Ethanol maybe James? Since it had been sitting up?

James92SE

iTrader: (31)

You mean run ethanol through it or you mean just to try to clean out the tank and fuel pump?

I have a new tank on the way and already have the new fuel pump sock. I'll put those in next week hopefully. Beyond that I just plan to replace the fuel filter at the same time and run some fuel injector cleaner through the first tank.

londonflu

No I mean ethanol caused that gunk in the fuel-tank, ya think?

Ethanol and Gasoline Storage Problems;

Ethanol mixed gasoline should not be stored long term. Ethanol’s storage shelf life is only up to 100 days. In 100 days or less, even under ideal conditions (low humidity, sealed fuel system), the alcohol part of the gasoline mixture will absorb enough water from atmospheric humidity and condensation to cause contamination. Phase separation becomes a concern after 100 days. When E10 becomes cloudy, then you know it is going bad due to water contamination.

CandiMan

iTrader: (1)

It's been over a week and I have not experience any more excessive cranking. So I'm going to call victory with the replacement of the fuel injector.

I am planning in re-installing my original PS to se what happens. If nothing changes then I'm advancing my timing back to 20 degrees, maybe a tad bit more. The stock 15 degree is for the birds

James92SE

iTrader: (31)

I thought I posted yesterday in response to this but it doesn't seem to be here now?

Anyway, you're probably right. The gas is definitely very cloudy.

Now I'm concerned about my turbo car since it's been sitting for about 3 months now with a nearly full tank.

I remember even just 6-7 years ago not having issues like this with gas. There's nowhere in DFW now to buy ethanol free gas. And just think they'll keep increasing the ethanol content as the years go on

londonflu

This is why sooner or later we're gonna have to bite the injector bullet again; since there's none in GA either. Just keep pumping premium and adding lucas on every other fill-up. Before ethanol fuel, there were no problems with these cars, but at 200k miles, how many of the fuel problems were due to ethanol? Hmm..