Strange Engine Problem

Started by Yokto · Aug 13, 2007 · 79postsSMF 2010–26

YoktoAug 13, 2007, 8:04 pm · #1

The engine is hard to start, thats the first problem not the biggest.
the secound and the biggest problem is strange.

if i give the engine full trottle it starts to rev up but dies at 2k rpm it starts again when it reaches 1k rpm, then it go upp to 2k and dies down to 1k again and so on... no missfires it just dies.

at half throttle it reaches 3k rpm and does the same thing.

if im carefull with the trottle then it can reach like 4-5k rpm before it dies.

I dont think the problem is with the ignintion system because ive checked with a strobe, when the engine dies, the stoboscope keeps flashing.

Im from sweden so if my english is bad, thats why

silverarrow27Aug 14, 2007, 4:28 am · #2

Maybe bad maf?

IggyEGuanaAug 14, 2007, 4:48 am · #3

Maybe TPS (throttle position sensor) too. But I have a feeling its MAF (mass air flow) sensor. Another term for it (actual Nissan term I think) would be AFM (air flow meter).

YoktoAug 14, 2007, 8:33 am · #4

Thanks for the replys

Can i test this someway without having to buy new stuff?

ive tried to disconnect the maf, when its disconnected the problem gets worse.

im on my way out now to check the TPS, i think its an potentiometer? so measuring it would not be to hard.

silverarrow27Aug 14, 2007, 4:36 pm · #5

That's the only way I know how to test if a maf is bad or not, by disconnecting it. If it gets worse then it's not your maf. Always worked for me.

Have you checked for any major vacuum leaks?

KeithAug 14, 2007, 6:49 pm · #6

No one has mentioned checking for codes.........have you?
Could be your CAS going out or maf, like mentioned above, or both for that matter....but before rushing out and replacing parts, check for codes first

PremoAug 14, 2007, 7:27 pm · #7

sent ya an email..

YoktoAug 15, 2007, 3:38 pm · #8

Premo: i have no emails from you :S

keith: i have checked for codes only one fails "air condition" and i dont have one. so i think everythin is i order there, i can go out and chack again was a year ago i checked, had the same probblem then so...

and what is CAS? how do i chek it?

silverarrow27: OK i have tryed that and the problem gets worse when i unplugg the maf. how do i check for vacuum leaks?

Thanks

KeithAug 15, 2007, 4:07 pm · #9

Have you disconnected the battery for any length of time, because that will clear the codes. The CAS is the Crank Angle Sensor, which is located in the distributor assy. I know mine threw the cas code when it crapped out......but mine wouldn't fire up at all when the cas died....so, this may not be your prob.
For vac leaks, check all the vac lines....if they're all original, they have to be dry rotted by now, and should be replaced anyways....this includes the big vac lines from the brake booster, and air regulator, as well as the little ones that connect to the intake mani, and charcoal canister

IggyEGuanaAug 15, 2007, 4:51 pm · #10

I don't know anything about the codes our cars throw but is it "air condition" or "air conditioner"? "Air condition" may be refering to a problem with the measurement or regulation of the intake air. Or I could be completely wrong, lol.

KeithAug 15, 2007, 5:38 pm · #11

There is a list of codes on the ecu cover

silverarrow27Aug 15, 2007, 6:07 pm · #12

KeithHave you disconnected the battery for any length of time, because that will clear the codes. The CAS is the Crank Angle Sensor, which is located in the distributor assy. I know mine threw the cas code when it crapped out......but mine wouldn't fire up at all when the cas died....so, this may not be your prob.
For vac leaks, check all the vac lines....if they're all original, they have to be dry rotted by now, and should be replaced anyways....this includes the big vac lines from the brake booster, and air regulator, as well as the little ones that connect to the intake mani, and charcoal canister

What Keith said. ^^^^^

PremoAug 15, 2007, 7:53 pm · #13

huh, thats twice now ive sent an email and nothing went thru. weird, pretty much all i said has already been covered...and i recomended picking up a shop manual. as far as vacuum leaks go, propane works great. the RPMs will go up when its introduced to the motor

YoktoAug 15, 2007, 10:24 pm · #14

I have a manual already that ive downloaded.

so I should spray propane at the vacuum "houses" (not sure at spelling there).

Now i have alot to try tomorrow thanks guys

nice signature btw premo, the movie "Kopps" from sweden have u seen it?

PremoAug 16, 2007, 8:31 am · #15

yea, just the raw gas. i know of alot of people that use starter fluid actually..

and thx for the info on the sig! ive always wondered what that was off of. i stole if off someone off hybridz and ive had heaps of people ask me now lol

YoktoAug 16, 2007, 1:25 pm · #16

The battery has been disconnected for a few months

Today ive checked the codes, the only one i have is "air conditioner" and for a car without air contitioner its O.K it says on the cover of the ecu.

I didnt have propane so i sprayd starter fluid on the motor, it didnt make any difference, i even tryed to spray it derectly in to the air
intake, then the engine almost died.

i had it running for some time today and dicovered that the enginge won´t start warm either.
but i pressed it over 5k rpm today, when i was realy careful with the throttle, if i press the throttle a little more it dies like i described.

ive checked the TPS its an "on/off switch" and its seems to be working when i measure it, but does not make a differance if i unplugg it. its on when the trottle is off, and on when i push the throttle.

KeithAug 16, 2007, 2:58 pm · #17

If you just re-connected the battery, then I would start and run it a few times, let it do what the problems are, and then check for codes again.
With a re-freshed ecu, it will take a few on/ off cycles of the motor running for the ecu to pick-up and store the codes

YoktoAug 16, 2007, 3:14 pm · #18

The battery has been in the car for a week now and it has been started almost everyday, checked the codes today there are no codes, unless im doing it wrong?

turn the key to on.
screw the little screw clockwise.
check for codes (if i remember right it flashes, (red 3 times, green 1 time)) over and over again utill i turn the screw back. this code is "air contition" and i dont have one so it shuld be O.K.

NitroAug 16, 2007, 6:56 pm · #19

I have the same problem right now.

Cold engine works poorly and dies, unless I keep it revving with the accelerator pedal. Warm engine idles poorly, bot won't die. If I press the accelerator fast - it dies. If I press slow and hold it somewhere in the middle - the engine goes for 2K-2.2K-2K-2.2K all the time, like something electric just won't let it rev up higher. And the smell of the exaust is awful + the black color spark plugs = too much fuel...
I tried to change the MAF and fuel pressure regulator valve - the same...

YoktoAug 16, 2007, 7:12 pm · #20

I cant tell what problem you have, maby wrong ignition order? does it missfire?, but i dont think our problem is related, my engine works great when i get it to start, idle is good both warm and cold, but when i press the throttle then my problem kicks in.

And it does not die, it dies and start again at lower rpm when trottle is fully pressed, or when i release the trottle.

NitroAug 16, 2007, 8:00 pm · #21

I've done the ignition by the book, seems to be right... I dunno, it gets too much fuel...

JonBAug 17, 2007, 12:54 am · #22

Mine behaved the same when my tack/rpm signal wire grounded out.

NitroAug 17, 2007, 5:59 am · #23

JonBMine behaved the same when my tack/rpm signal wire grounded out.

Where is this wire???

YoktoAug 18, 2007, 4:26 pm · #24

the tach meter wire is located under your airfilter, its a plug contact connected to the primary transistor. tip. you can lock at the secondary transistor its the cable that does not exist on the secondary transistor.

NitroAug 18, 2007, 4:33 pm · #25

Ok, thanks!

rookieAug 19, 2007, 6:20 am · #26

Have you thought of checking your fuel pressure? Most of the time, problems like that is because of a bad fuel filter!

YoktoAug 19, 2007, 6:30 pm · #27

I´ve checked the fuel filter, seems alright, can it bee the fuelpump? how do i check it?

NitroAug 19, 2007, 6:33 pm · #28

IMHO you need to check the pressure in the fuel rail, if you want to know about the filter or the pump. If I'm not mistaken, it should be 2.2 PSI at the ignition on / pump working. Same in the idle. If lower - then the filter or the pump is bad.

P.S.: my latest upgrade - fuel pressure regulator

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rookieAug 20, 2007, 3:49 am · #29

First of all, you'll have to get a fuel pressure guage from any auto parts store. It should be hooked up anywhere after your fuel filter. It's hooked up with a T fitting on to your fuel hose line. You probably have to splice into your fuel hose.

YoktoAug 22, 2007, 12:57 pm · #30

Ok here is the situation, ive bought a fuel pressure meter and checked the fuel pressure, is good eaven when i try to step at the gas, the pressure does not change at all infact, stays good.

ive checked a vaccum line from the intakemanifold to the charcoal canister, at idle the vacuum is good and when i press the trottle a little so it can rev its still good, but when i press the trottle hard the vacuum drops to zero, is this because its a turbo? or is this a problem?

Is there more i can check with my fuel pressure/vacuum meter?

NitroAug 22, 2007, 8:21 pm · #31

My car stays in the shop for the third day now - they don't know what the problem is. Tested every sensor, all the places, where the vacuum can leak... even put the MAF directly to the air intake without the turbo - still everything remains the same... No good idle, it's all shaking, no revs, no power... well, the car just don't run at all.

rookieAug 22, 2007, 10:35 pm · #32

YoktoOk here is the situation, ive bought a fuel pressure meter and checked the fuel pressure, is good eaven when i try to step at the gas, the pressure does not change at all infact, stays good.

ive checked a vaccum line from the intakemanifold to the charcoal canister, at idle the vacuum is good and when i press the trottle a little so it can rev its still good, but when i press the trottle hard the vacuum drops to zero, is this because its a turbo? or is this a problem?

Is there more i can check with my fuel pressure/vacuum meter?

Okay, make sure your fuel pressure is where its suppose to be. I think most import is at 35 to 38 psi, you probably have to check your service manual book. I don't know what brand your fuel pressure is and it may not be accurate. But lets assume it is. If your psi is too low, it will not give your engine a good air fuel ratio to burn, even though your engine is running normally. Thats why your motor is dying down when you apply more throttle. If your fuel is too high, it will also cause the same problem as above and not only that, your exhaust pipe will be black in the tip. If that is the case, you may have a bad fuel pressure regulator!

As for your vaccume guage, turbo or no turbo it will run the same at idle. At full throttle, its gonna read 0 (thats normal) At idle, the needle should be steady at 15 to 18hc. If its wavy a lot then you have a problem! If you want to learn more on how to read the vaccume guage, refer to a chilton manual book. There is a page on how to read vaccume guages. By the way, If you have a aftermarked boost guage, that is already a vaccume guage. You can use that to read any problems that you may have.

rookieAug 22, 2007, 10:51 pm · #33

NitroMy car stays in the shop for the third day now - they don't know what the problem is. Tested every sensor, all the places, where the vacuum can leak... even put the MAF directly to the air intake without the turbo - still everything remains the same... No good idle, it's all shaking, no revs, no power... well, the car just don't run at all.

Sometimes problems occurs after you've worked on it or upgraded something, YOU KNOW; those kinds of things. My guess is check all ignition components and check your fuel pressure. Those are the first thing that needs to be checked first before you go into bigger and more expensive stuffs. I noticed you have a aftermarked fuel pressure regulator! Unplug your vaccume line that goes to your regulator, sometimes it will leak fuel just enough to where your motor will still run but not right. In the mean time I will ponder on your problem some more!

gerrybgAug 23, 2007, 12:21 am · #34

Have they tested the voltage output from the MAF to make sure its correct??

NitroAug 23, 2007, 6:03 am · #35

rookieSometimes problems occurs after you've worked on it or upgraded something, YOU KNOW; those kinds of things. My guess is check all ignition components and check your fuel pressure. Those are the first thing that needs to be checked first before you go into bigger and more expensive stuffs. I noticed you have a aftermarked fuel pressure regulator! Unplug your vaccume line that goes to your regulator, sometimes it will leak fuel just enough to where your motor will still run but not right. In the mean time I will ponder on your problem some more!

I bought the aftermarket fuel regulator already after the problem started... I thought that this is the answer. Ignition is set by the book, fuel pressure is normal... But it's still too rich (black smoke + black spark plugs).

rookieAug 23, 2007, 6:55 pm · #36

NitroI bought the aftermarket fuel regulator already after the problem started... I thought that this is the answer. Ignition is set by the book, fuel pressure is normal... But it's still too rich (black smoke + black spark plugs).

Have you checked your air filter to see if its dirty? If thats not your problem then your problem lies internally. You could have bad injectors, did you upgrade them at all? You may also have a bad 02 sensor, which will tell your computer to increse the fuel amount. A bad coolent temp sensor will cause the same problems too, during cold temperture it tells the computer to add more fuel until it reads a hotter temp and then the ecu will shut the extra fuel. This works like a cold start injector, since turbo cars doesn't use cold start injectors. Try checking those for now!

NitroAug 23, 2007, 7:06 pm · #37

Ha, I got answers to all these questions!

- With or without air filter it works the same.
- I bought a different set of original injectors. I had 3pcs of one type and 1pcs some different type before. But the problem started not after I changed it.
- I don't have o2 sensor
- Temperatire sensor works, we tested it.

The car runs absolutely the same even when we put air intake with MAF not through the turbo - so this is not because if the turbo neather. 4-th day at the shop and still no answers...

rookieAug 23, 2007, 10:59 pm · #38

NitroHa, I got answers to all these questions!

- With or without air filter it works the same.
- I bought a different set of original injectors. I had 3pcs of one type and 1pcs some different type before. But the problem started not after I changed it.
- I don't have o2 sensor
- Temperatire sensor works, we tested it.

The car runs absolutely the same even when we put air intake with MAF not through the turbo - so this is not because if the turbo neather. 4-th day at the shop and still no answers...

Since we discussed everything possible with fuel dilvery then my last thought would be to check oil conditions and level. Too much oil in the crankcase can cause alot of smoke and its hard to tell if its black or blue smoke when that happens. Im starting to think your problem is not your fuel but your engine oil getting into your combustion chamber and burning out the exhaust pipe. My thoughs are, do a compression and leakdown test! Also, at idle, does your boost guage needle reads steady at -18hc?

silverarrow27Aug 24, 2007, 1:00 am · #39

Maybe your coils are taking a shitter? Perhaps your distributor assembly?

NitroAug 24, 2007, 10:33 am · #40

I think we finally found something!

Changed the idle valve, or how is it calls, thing under the throttle body with a connector in it. We changed with the same from the FJ20E engine that is also working poor, but the car is idling and revving much better. The guy told me, that this thing will fit from some Mazda (hard to find the original here), and we will put Mazda unit in to see what will happen.

About the compression it is more or less equal in all cylinders but... When I disassembled the engine before I noticed, that the pistons were not original. They were with places for 4 valves, CA18ET have only 2 per cyllinder. Well, for 2 month I couldn't find something better, so I put them back in. Also, on that time, I had no service manual at all, so I didn't know about what compression ratio must be inside.
So now I have compression ratio 11.0 - 11.5 on CA18ET turbo engine. ) Cool, isn't it? )
I just start looking for CA18DET for the swap now for a reasonable price, because I doubt, that my engine will last long with that compression ratio, and I'm not able to find the original pistons.
Well, anyway, I'll tell later in this topic about the idle valve. If it will be better with the Mazda unit.

rookieAug 24, 2007, 12:53 pm · #41

Nice to know that you'll finally found something. The problem you found, I think its the throttle position sensor (tps). As goes for your pistons, you may have the flat top piston from the ca18det. Maybe you might even have the whole block with the ca18et head. That combo works but with 11 as a comp. ratio for turbo it can blow up easly. Best thing to do is swap for a ca18det.

NitroAug 24, 2007, 4:27 pm · #42

No, its not TPS, it's from the other side and lower.

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KeithAug 24, 2007, 4:45 pm · #43

Thats the air regulator......alot of Nissans use them....including z32's and s13's, s14's with KA motors

NitroAug 24, 2007, 4:50 pm · #44

Yeap, right - air regulator. It's somehow connected with the idle problems and the total air / fuel mixture ratios, right?

KeithAug 24, 2007, 5:03 pm · #45

NitroYeap, right - air regulator. It's somehow connected with the idle problems and the total air / fuel mixture ratios, right?

Possibly idle problems. The function of it is.....it makes the engine idle higher(1200-1400 rpms) after cold start-up. There is a disc inside it that opens and closes that raises and lowers the idle based on ambient air temps....for the first few minutes after start-up.

NitroAug 24, 2007, 5:12 pm · #46

As far as i know it's doing it mechanically. When it heats up - it closes, and the sesor is giving the info to the ECU. When the car is cold the ECU gives more fuel. And if this thing is broken... "always cold"... the ECU always gives too much fuel and the problem starts... Can it be true?

KeithAug 24, 2007, 5:17 pm · #47

NitroAs far as i know it's doing it mechanically. When it heats up - it closes, and the sesor is giving the info to the ECU. When the car is cold the ECU gives more fuel. And if this thing is broken... "always cold"... the ECU always gives too much fuel and the problem starts... Can it be true?

It's possible....I've never seen one broke that way....most break in the "warmed up" opened position. Mine was broke for years.....it ran fine, it just didn't idle high when I first cranked it.

PremoAug 24, 2007, 6:24 pm · #48

gerrybg Have they tested the voltage output from the MAF to make sure its correct??

balls, someone beat me to it!!!

also, who's thread is this now?? nitro's or yokoto's?

NitroAug 24, 2007, 6:29 pm · #49

What's the difference? Maybe, if our problems is in somewhat similar, this will also help Topicstarter?

Anyway, you'd better tell something usefull Premo then to aks, who's topic is this.

YoktoAug 24, 2007, 7:20 pm · #50

Im glad that you might found the problem nitro

my problem do not seem to be related to yours, and ive checked the most that you guys have told me too check, soon i will send it to the junkyard or to a workshop if its not to expensive so it can be fixed.

I had the same problem even when my turbo was "stuck" (the impeller would not moove). ive recently changed it to a new one hoping that it would fix the problem, but the problem remains. no difference at all infact. I dont seem to get any boost at all even when i rev it over 5k rpm, maby i need to have full throttle to get boost, but the car does not allow me then it dies just as i described.

Its not ignition system because ive tryed with full trottle with a stroboscope and it flashes all the time even when the car dies.

The maf seems to be working, if i unplugg it the problem gets worse.

i have no codes...

new turbo

measured the TPS

measured fuelpressure.

masured vaccum seems alrigt but i dont realy know how i do it? or where.

I have done alot more, but im no mecanic so i might doing it wrong.

thanks anyways youre great guys, Anyone knows what moore i can check?