[FIXED] Vibration and sputtering while on Idle after warming up the car

Hello Tutti57.

The evap purge valve not yet. Pinch the small hoses?
I was trying to clamp the brake booster but the hose is made of plastic. I have to find another option maybe unplug it from the intake manifold and plug the hole and see if that works

pls check for any load in engine like ac compressor , sticky generator bearing,or water pump

Yep, you can pinch off the hose that goes to the intake and see if you get an improvement. Also correct that you can pull the booster hose off and cover the hole on the engine side.

Nissan Technician

dazs wrote: Hello guafa,

I really had no way to block that IACV passage with my finger while its running because its inside the air intake pipe and will stall the moment i pop it open. So I had it idle until operating temperature pop the air intake and placed a fold up shop towel enough to block the passage. I placed the air intake back and started the car (result) it started fine just the same. Making sure I satisfy myself I place more shop towel around the throttle plate (result) started fine like the first time.

If you unplug the MAF and take the tube off before you start the car, it should stay running. It might stall once it twice at first. Then you can block the passage as suggested previously

Hello Renjith

AC compressor is been bad for a few years only ac clutch failed but pulley runs fine maybe leaking compressor oil. No noise and next in line for new part. Water pump is good otherwise the car would overheat but no noise too

Update!

-I did multiple test to why the car continues to shake and sputter while on idle. No check from day 1.
-I was hoping the smoke test can point me to the right direction but not completely. 4 vacuum leaks and the problem is still there.
-Unplugging in separate occasion ( Evap, Brake booster and PCV ) and plug the open hole, the engine still runs with minimal difference.
-I tried to unplug most of the sensors and PCM response with a check engine which tell you the PCM is working properly. Most of the sensors are even new.
-Blocking the small airway at the throttle body near the plate designed for IACV (result) Engine still start while the engine is warm.
-I did a Block Test with blue fluid at the coolant reservoir (result) negative head gasket issue.

What I will do next

Replace Intake manifold gasket and do close inspection of everything once its off.
The true issue is that the 2002 Ford Focus Zetec has the intake manifold from the back near the firewall which is hard to have a close look. I know it has signs of leak but smoke test didn't show.
The gasket is long over due so I'm ok with it being 383,000 miles. This car has a lot of work done already and compression test all (4 cylinder 150/160 psi} means healthy engine

Today: This car just passed Smog Check

Hi Dazs,

Let's explore another direction. Fuel trim numbers are telling that pcm is adding fuel, that could be due to.

1. O2 sensor is detecting too much oxygen (please check O2 sensor activity while sputtering).

2. MAF sensor is telling pcm that there is too less air. (Please check MAF readings while sputtering).

3. PCM is reading the correct amount of air, is comanding the correct amount of fuel, but injectors are not responding as they should (please check fuel pressure while sputtering and perform a balance test (with engine off of course).

It would be great if you post a video with as much data stream as you can while sputtering (specially maf, map, trims, o2, iac, injectors duty cycle).

Regards.

I think it would be usefull also, knowing if this sputtering ONLY happens in closed loop.

Hello guafa,

I will do another test using your info before I start the intake manifold gasket replacement. I will post the scanner reading or on realtime

Update

Completed the intake manifold cleaning and new gasket, I replaced the throttle body with upgraded model (used) @junkyard and TPS (used) (result) RPM 700 +/- and IACV 34% +/- both on specs. IACV no longer drops to 19.92%. Replace another EGR Pressure Feedback Sensor (used) & (1st time replacing) EGR Valve Control Switch (used) (result) No much difference, maybe a little. The sputtering is still there and I also notice too much water coming out from the tail pipe and water spraying at the Exhaust Muffler (Front) weep hole. Maybe its a little better because the intake manifold & throttle body but the sputtering is still there. My Block test was negative... (Blue) fluid didn't change to (Yellow). Possible that Block Test was not accurate? Doing the chemical test at the coolant reservoir is not best place or not accurate. I still have moisture at my coolant reservoir container and that's been like that... I just ignored it.

See Attachments Video
1. Water in the tailpipe


2. Water spraying in the front muffler (middle part of the car)


3. Engine vibration, shaking or sputtering on Idle (after 5 minutes warmup)


Some improvement but I wil not stop until that vibration, shaking or sputtering on idle stops

What are your short and long-term fuel trims now, held at idle, 2k, and 3k rpms when the engine is warmed up?

Nissan Technician

i am seconding what "NOAH" asked.
Did you put the idle adjustment screw back where it was before you moved it? im pretty sure that its original setting was a base line position that the the pcm uses for normal operation. changing this screw setting may now create more problems inside of the original problem, by throwing off all of the(known good) base line positions for the IACV, thus making any diagnosing after the fact, impossible to get known good results . IT needs to be put back, if that can even be accurately accomplished at this late venture

Patrickreaves,

When I decided to adjust the screw I made sure to learn how it's done. Danner has a video about that so it wasn't a problem. Anyway, I replaced the whole throttle body with a used upgraded model which the screw is still on factory setting and RPM/ IACV % are all in specs. All the work done vibration and sputtering is still there.
I probably need to recheck my engine timing, rule out head gasket and exhaust manifold gasket. I'm running out of simple solution.

Tutti57,

RPM 674.8
LTFT 14.84%
STFT 1.36%

FYI
I'm not driving this car. Last week was the longest drive I did because I was clearing the P1000 code for smog check. I successfully pass the smog check. I'm working on this car all the time and I remove the negative of the battery too. I don't know if the PCM would remember the LTFT% accurately.
Today the P1000 code is back because I had to clear codes again.

Alright, so then the idle adjust screw wont be an issue.
Are you adding coolant? does that water coming from exhaust look excessive to anybody ?
Have you put a vacuum gauge on it?

what are those fuel trims held at higher rpms?

Nissan Technician

Update!

After weeks of working with this car I finally solved the mysterious problem. Ok Everybody should know that this 2002 ford focus is 382,000 miles with a compression reading of 150-160 psi. I'm in the road of restoration and replacing parts when needed. I did 2 timing belt replacement and another one a month before I started to pay attention with the vibration and sputtering on idle. I don't drive this car too much or sometimes on the weekend because I have a newer car. All the work I've done with this car was necessary because I will give this car to my daughter when she turns 18 and want it perfect.

Problem

Vibration and sputtering on idle after warming up.

Work done before the problem

Removing the timing belt to have access to the crankshaft seal for replacement.

Tools: Ford Camshaft Alignment Kit which I didn't use the aluminum bar because it was too thick
I manage to buy a replacement bar which was too thin and loose but actually works just keep in mind of the slack when tightening the bolt

Solution

The problem/ mistake was to never use a alignment bar that is loose or 3mm off from OEM tools. It should be perfect fit or a little tight ok.
What happened was I check my timing and I noticed that the slack from the alignment bar I made caused the CAMSHAFT to turn 1/4 of an inch while I was tightening the bolt to specs. DOHC the (left) CAM was 1/4 of an inch off and (right) CAM was correct on specs. I took the advice of a guy who said that 1 skip tooth can cause that exact symptoms your having. The car will not give any (check engine) and scanner will not help.
I was blown away when it actually worked!

No more Vibration and sputtering on idle after warming up

Make sure use the proper alignment tools and keep the alignment 100% perfect

See video

Engine Vibration and sputtering which the (left) CAM is 1/4 of an inch off


Engine is in perfect alignment using the proper Alignment Bar with Zero slack


THANKS FOR EVERYONE'S HELP!!!

Way to stick with it, glad you got it squared away. Thanks for updating us with the fix!

I think this case it a good reminder for every one of us that makes a living diagnosing cars....

Whenever there is a new symptom, we always gotta go back to the simple question "What changed?" In this case, the symptom didn't start until the timing belt was replaced, if I understand correctly. Now I know that there were some other circumstances surrounding this particular case, where the OP didn't drive the car often and there were other faulty components, so it maybe wasn't very obvious.

But I can't tell you how many calls I get, even on a weekly basis, where a new symptom surfaced after performing a repair. Almost 100% of the time, it was caused by something related to the original repair performed or the part that tech installed. It's so easy to start chasing symptoms and forget this, and I am guilty myself at times.

Anyway, great work nailing this one down and not giving up!!

Hi everyone,

I still have some pending conclusions about this one.

*Does this car still have fuel trims out of range?

*It makes sense that sputtering was due to a timing adjustment. Ok

*About IACV bouncing, I bet all my coins to a vacuum leak (not to a new throttle body)

*Does it make sense that IACV bouncing could be confirmed looking at map/maf bouncing also?