I've also been having a a vibration problem for about a month now. When I press on the gas pedal (not all the time but sometimes) I feel a strong vibration, it also happens when coming to a stop.

I honestly have no idea what it is or where to start. I'll take any suggestions you guys have.

Just some background info - I recently did the spark plugs myself (all but #6. I dont have the tool and cant even take the boot off, so I figured i'd leave it to a pro) NGK iridiums - I was told not to gap them because of the platinum tip but it was farely close in the first place, new spark plug wires, and the entire A/C system was recently worked on by a mechanic.

Thanks in advance!

I was also told not to gap them but I did for good measure, they were pretty off

It doesnt sound like you have a misfire, how is your transmission? diffs? have you maintained those fluids? as for your engine dying im

As far as vibration goes that could very well be a suspension issue: how are your bushings in th rear (since you didn't say where the vibration is coming from I'm gonna throw a couple of options our way), how are your front stuts/stut tower mounts & is you car in alignment (I know not really a suspesion issue but close enough)?

I bought it used (90,000mi) so I couldn't tell you if the maintenance has been performed before. But I plan on draining/filling these sometime this week - I'll let you know if that does anything. By the way, from what I've read these don't seem like very difficult processes. Am I right?

Quote, originally posted by fukinitupagain »

Ron, are you throwing any codes? Hows your alt. as well (this is for the R50 dying issue)? This could very well be a distributor issue as well. Have you had a good amount of water in the engine compartment recently??

Forgive me, I'm still learning. My check engine light would have to be on in order to have any "codes" correct? If so, then no the light isn't on. How would I know if the alternator is in good condition? I'm going to replace the rotor, as far as the distributor - visually everything looks ok but anything I should look for? And no... no water.

Quote, originally posted by fukinitupagain »

As far as vibration goes that could very well be a suspension issue: how are your bushings in th rear (since you didn't say where the vibration is coming from I'm gonna throw a couple of options our way), how are your front stuts/stut tower mounts & is you car in alignment (I know not really a suspesion issue but close enough)?

From what I described to you think it could be something suspension related? Idk, it just feels like something electrical or from under the hood. BUT i have no idea. I am also completely clueless when it comes to under the car/suspension related issues. You'd have to talk me through it like a third grader in order for me to answer.

Thanks a lot guys. Appreciate it.

Quote, originally posted by Ron Burgundy »

How would I know if the alternator is in good condition? I'm going to replace the rotor, as far as the distributor - visually everything looks ok but anything I should look for? And no... no water.

Unless you are familar with these engines your best bet is to go to mechanic you trust & have them run tests to see if they are working properly

Quote, originally posted by Ron Burgundy »

From what I described to you think it could be something suspension related? Idk, it just feels like something electrical or from under the hood. BUT i have no idea. I am also completely clueless when it comes to under the car/suspension related issues. You'd have to talk me through it like a third grader in order for me to answer.

If its not suspension or tranny related then I wouldn't be too sure as to what it could be. I used to have an old Bronco that I wheeled the hell out of & broke a couple of motor mounts on different occassions so the engine literally jumped around & would sometimes pull what little electrical parts that were there out while going around corners or what not (cause the engine would lean to one side) & would kill the engine but I've never heard of that with 4x4 Nissans. Plus I doubt that you wheel it that hard if you wheel it at all, correct.

Very quickly off topic, is there a way to light 'em all up so I know whats working and whats not? For example, the check engine light will come on when something is wrong, well how the hell am I supposed to know if something is wrong if the bulb is out all together! Any way?

Back on topic, I read about a vibration problem that could come from the driveshaft in the good ol' repair manual. This sound reasonable? Also another reason to possible rule out suspension is that the vibration happens when at idle as well. Doesn't sound suspesion related right?

You guys are the s***. Thanks

distributor and maf - look good

air filter is slightly dirty, could probably use a little cleaning but nothing major.
throttle body just cleaned

also about the o2 sensors they're located along the exhaust once again not certain about the specific locations on our trucks...but then again if they o2 sensors are bad it should be throwing a code

I still think it sounds like the distrbuter but I forgot about the o2 sensors but I'm like you if it was not workiong properly, or the MAF for that matter, would throw codes. Oh course you think, Ron, that those bulbs might be out (I highly doubt that though).

I turn the key and it makes the "car starting sound" but its really slow and pretty much sounds like death/dying.

Battery? Anything?

I will take you up on that offer eventually. I'll hit you up when i'm ready to finish that. Thanks a lot I appreciate it.

I would also check the distributor and wires to ensure proper connections and make sure nothing has come loose and make sure there is no particulate between the plugs and the spark plug boots. You should always spray the boots with some di-electric grease to ensure a secure connection.

I'm not super familiar with the 99.5 model, but when you cleaned the throttle body did you reset the ECU and relearn the pedal position and idle air volume? I don't know if this was necessary for the 99.5 model, but this is always necessary after cleaning/replacement of the MAF sensor, cleaning of the throttle body, and after putting in an aftermarket intake.

Just my $.02

good luck!

I'll keep you updated.

One or more of those things go bad, then you lose performance and eventually it won't start at all. Seems to be what you're experiencing. How's the air and fuel filters?

Oh, and for your earlier question, most of the important dash lights should flash on briefly when you turn the key to the 'on' position. A lot of them will stay lit if you leave the key in the on position without starting the engine.

So how do you reset the ECU and relearn the pedal position and idle air volume? I've never heard I need to do this.

Thanks again!

----RESET ECU (easier method below, I recommend it over this method)----

1. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.

2. Repeat the following steps (2a and 2b) procedures quickly five times within 5 seconds.

2a. Fully depress the accelerator pedal (HARD).
2b. Fully release the accelerator pedal.

3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the CEL starts blinking.

4. Fully release the accelerator pedal (while the CEL is still blinking).

5. Wait about 10 seconds.

6. Fully depress the accelerator pedal and keep it for more than 10 seconds.

7. Fully release the accelerator pedal (The CEL light will continue to blink).

8. Turn ignition switch to “OFF” position and now you can start the car. The CEL light should be gone.

If the CEL light continues to remain ON, repeat the above steps. Timing is EXTREMELY critical to resetting the ECU.

---- EASY METHOD ----

1. Ignition "ON", count to 3.

2. Depress/Release pedal 5 times...hard and fast.

3. Count to 10 (not 7!) and fully depress pedal

4. Count to 12 (SES should be blinking), release pedal

5. Count to 10, depress pedal

6. Count to 10, release pedal.

7. Turn off ignition, then start engine. Done!

---- Accelerator Pedal Released Position Learning ----

1. Make sure that accelerator pedal is fully released.

2. Turn ignition switch “ON” and wait at least 2 seconds.

3. Turn ignition switch “OFF” wait at least 10 seconds.

4. Turn ignition switch “ON” and wait at least 2 seconds

5. Turn ignition switch “OFF” wait at least 10 seconds.

---- Throttle Valve Closed Position Learning ----

1. Make sure that accelerator pedal is fully released.

2. Turn ignition switch “ON”.

3. Turn ignition switch “OFF” wait at least 10 seconds.

Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.

---- Idle Air Volume Learning ----

NOTE:
Before perform “Idle Air Volume Learning”, make sure that “Accel-
erator Pedal Released Position Learning” and “Throttle Valve
Closed Position Learning” are completed.
If not, perform “Accelerator Pedal Released Position Learning”,
EC-81 and “Throttle Valve Closed Position Learning”, EC-81.

1. Start engine and warm it up to normal operating temperature.

2. Check that all items listed under the topic “PREPARATION” (previously mentioned) are in good order.

3. Turn ignition switch “OFF” and wait at least 10 seconds.

4. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.

5. Repeat the following procedure quickly five times within 5 seconds.

1) Fully depress the accelerator pedal.
2) Fully release the accelerator pedal.

6. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops blinking and turns ON.

7. Fully release the accelerator pedal within 3 seconds after the MIL turned ON.

8. Start engine and let it idle.

9. Wait 20 seconds.

10. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifications.

11. If idle speed and ignition timing are not within the specification (750rpms +/-50rpm), “Idle Air Volume Learning” will not be carried out successfully.

Let me know if this works for you!