Need your help with a engine issue - videos and pictures inside

[Raf99]

Hi,

Not sure how to explain this one in the title, but I've been troubleshooting this one for more than a week now.

Issue:
- Car starts to shake and studder under load
- No check engine light
- Will happen at any RPM except idle

(see video)


As you can see it idles fine, revs fine, but when holding a certain rpm it starts to shake and drops off. It never stalls, there are no leaks, no other issues.
Items which have been replaced recently:

- New spark plugs
- New spark plug wires
- New distributor cap
- Used good working ignitor

I thought this was the TPS so i tested this. The TPS wire has 5V, but I did not test closed/open throttle on this wire. The sensor tested fine with below 1000ohms on closed throttle and 3000 - 4000ohms on open throttle (although the manual states it should be 3000 - 6000ohms).

Looking at the plugs we see they look fine. Pulling the wires off while the issue is happening does make things worse, implying that they are working fine.

Plug1


Plug2


Plug3


Plug4


I also tried unplugging the EGR, this did not make a different.
I did not try unplugging the TPS during idle or revving, i'm not sure if one can do that. But I really need some more ideas to try. There's no check engine light. Running out of ideas.


Please help.

[reklipz]

Just a shot in the dark here, and I'm sure it's fine, but the throttle cable isn't all jacked up, is it?

Otherwise, I don't really know what could be causing this. I might try resetting the ECU trim and play with the engine w/ and w/out the IACV plugged in and see if it behaves differently. I expect it doesn't, but who knows.

If it's not air, maybe it's fuel? Might explain the stuttering under load.

[Raf99]

Just a shot in the dark here, and I'm sure it's fine, but the throttle cable isn't all jacked up, is it?

Otherwise, I don't really know what could be causing this. I might try resetting the ECU trim and play with the engine w/ and w/out the IACV plugged in and see if it behaves differently. I expect it doesn't, but who knows.

If it's not air, maybe it's fuel? Might explain the stuttering under load.

Throttle cable is fine. I'm thinking of changing the ECU soon.
Doubt its fuel as a new fuel filter was recently put in too (forgot to mention that in the first post)

[EsperHamid]

it has nothing to do with the plugs that's for sure else it the problem would have persisted on all RPM stages.

I am learning as the time goes by, but from the looks of it, it looks like something that either has to do with the Engine mounts or the Exhaust having cracks or old rubber bushings.

that's what I can say.

[1990[H]accordex]

it has nothing to do with the plugs that's for sure else it the problem would have persisted on all RPM stages.

I am learning as the time goes by, but from the looks of it, it looks like something that either has to do with the Engine mounts or the Exhaust having cracks or old rubber bushings.

that's what I can say.

did you watch the video? rpms don't drop cause of a engine mount

[Raf99]

did you watch the video? rpms don't drop cause of a engine mount

Yep. No way engine mounts cause rpms to drop while holding my right foot steady.

Hoping for some mechanics to show up in here and give some helpful advice or even something to try.

I can tell everyone reading this that the problem started on a 2 hour drive back home, about 15min left on the trip. When I mashed my foot into it, the problem went away or things seemed to "kick in".


I think I'm going to replace the fuel filter for shits and giggles. Although it was done 3 months ago, its the only thing I can remotely see doing this.

[1990[H]accordex]

Yep. No way engine mounts cause rpms to drop while holding my right foot steady.

Hoping for some mechanics to show up in here and give some helpful advice or even something to try.

I can tell everyone reading this that the problem started on a 2 hour drive back home, about 15min left on the trip. When I mashed my foot into it, the problem went away or things seemed to "kick in".


I think I'm going to replace the fuel filter for shits and giggles. Although it was done 3 months ago, its the only thing I can remotely see doing this.

maybe doing ur gas mileage tests, u may have quite possibly picked up something, it's always a possibly

[1990[H]accordex]

http://www.cb7tuner.com/vbb/showthre...le+3000&page=2

seems like this fellow had something similar wrong raff, he also did not solve it, but I find it interesting people are mentioning fuel pump.

[Cb3vtec]

That looks like a fuel problem to me, those sparkplugs do not have the right color. They should be chocolate brown. Check fuel pressure and fuel pump. Injectors? can you take a drive and drive it as hard as you can and then check the plugs again. They should not be white or look "brand new"

[1990[H]accordex]

That looks like a fuel problem to me, those sparkplugs do not have the right color. They should be chocolate brown. Check fuel pressure and fuel pump. Injectors? can you take a drive and drive it as hard as you can and then check the plugs again. They should not be white or look "brand new"

white on the plugs would be carbon deposits? it could be OP flash from camera causing an illusion.

[Raf99]

http://www.cb7tuner.com/vbb/showthre...le+3000&page=2

seems like this fellow had something similar wrong raff, he also did not solve it, but I find it interesting people are mentioning fuel pump.

Yep. That is my exact problem!! But I'm not about to just to swap a fuel pump. That is an outrageous amount of work!

That looks like a fuel problem to me, those sparkplugs do not have the right color. They should be chocolate brown. Check fuel pressure and fuel pump. Injectors? can you take a drive and drive it as hard as you can and then check the plugs again. They should not be white or look "brand new"

white on the plugs would be carbon deposits? it could be OP flash from camera causing an illusion.

Yep. Was the flash on the camera making them look white like that.

I can check the injector wire resistance, but I don't have a stethoscope for listening to injectors.

How does one check the fuel pressure? Gauge needed?

[1990[H]accordex]

Yep. That is my exact problem!! But I'm not about to just to swap a fuel pump. That is an outrageous amount of work!





Yep. Was the flash on the camera making them look white like that.

I can check the injector wire resistance, but I don't have a stethoscope for listening to injectors.

How does one check the fuel pressure? Gauge needed?

In the Haynes manual it says to relieve fuel pressure, and remove service bolt from atop service fitting located on fuel rail, also you'll need fuel pressure gauge and a adapter to test pressure. start the car check fuel pressure. pressure should be between 30 to 38 psi. Then unhook vacuum hose from fuel pressure regulator, with engine idling check pressure again, this time should read 40 to 47 psi. Its all in the book anyways

[Accord problems]

have you tryed changing you're o2 sensor ? have you made changes to your timing? Either way, check the timing... also, when was the last time you changed those plugs?

[Raf99]

In the Haynes manual it says to relieve fuel pressure, and remove service bolt from atop service fitting located on fuel rail, also you'll need fuel pressure gauge and a adapter to test pressure. start the car check fuel pressure. pressure should be between 30 to 38 psi. Then unhook vacuum hose from fuel pressure regulator, with engine idling check pressure again, this time should read 40 to 47 psi. Its all in the book anyways

Ok, I will pick up one of these and a new fuel filter.

have you tryed changing you're o2 sensor ? have you made changes to your timing? Either way, check the timing... also, when was the last time you changed those plugs?

- I have not checked/replaced the O2, do you think I should? I wasn't aware of a bad O2 having these symptoms.
- I have not made changes to the timing. (not sure how to check that without a gun or taking the cover off)

Changed the plugs about 6 months ago. They are all firing fine.

[Accord problems]

if you're o2 goes bad it can cause a lean/rich mixture . i believe you are running lean . if you're timing is off it can cause a incomplete burn of the fuel and lots othere stuff.