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Author Topic: engine vibration  (Read 6878 times)

Offline Low87

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engine vibration
« on: May 25, 2011, 08:22:45 am »
The 89 Jimmy has some vibration in the steering wheel at idle.  If you pop the hood with the engine running you can see the engine moving side to side more than it should.  I'm hoping it's just engine mounts, but is there anything else I should look at?
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Offline PromiseKeeper

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Re: engine vibration
« Reply #1 on: May 25, 2011, 08:30:59 am »
Could it be that your idle is just set too low? See if it gets better by increasing the engine speed just a tad with the gas pedal while its idling and see if it smooths out.
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Offline Low87

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Re: engine vibration
« Reply #2 on: May 25, 2011, 01:42:50 pm »
That seems to help for the most part.  How do I adjust idle on a TBI engine?
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Offline VileZambonie

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Re: engine vibration
« Reply #3 on: May 25, 2011, 08:44:40 pm »
Don't.

Unplug the vacuum hose at the egr valve and see if it idles better.
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Offline the_legend_1981

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Re: engine vibration
« Reply #4 on: May 25, 2011, 10:04:05 pm »
what if it does? leave it unplugged?
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Offline 1979C20

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Re: engine vibration
« Reply #5 on: May 26, 2011, 12:26:39 am »
Quote from: the_legend_1981 on May 25, 2011, 10:04:05 pm
what if it does? leave it unplugged?
If it does than than the EGR is bad and either needs replaced or removed.
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Offline Blazin

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Re: engine vibration
« Reply #6 on: May 26, 2011, 05:46:47 am »
Probably not the case here but bought a truck with a 350 one time that did this. Turns out some dub had put a 400 flex plate on it!
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Offline Low87

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Re: engine vibration
« Reply #7 on: May 26, 2011, 08:15:26 am »
Thanks Vile, I'll check that tonight.  Acceleration & driving is smooth, so hopefully it's something simple.
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Offline VileZambonie

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Re: engine vibration
« Reply #8 on: May 26, 2011, 01:10:18 pm »
Quote from: 1979C20 on May 26, 2011, 12:26:39 am
Quote from: the_legend_1981 on May 25, 2011, 10:04:05 pm
what if it does? leave it unplugged?
If it does than than the EGR is bad and either needs replaced or removed.

No, if it does that means the EGR solenoid is sticking allowing vacuum to the EGR valve at idle. Very common problem.
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Offline 1979C20

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Re: engine vibration
« Reply #9 on: May 26, 2011, 03:02:53 pm »
Quote from: VileZambonie on May 26, 2011, 01:10:18 pm
Quote from: 1979C20 on May 26, 2011, 12:26:39 am
Quote from: the_legend_1981 on May 25, 2011, 10:04:05 pm
what if it does? leave it unplugged?
If it does than than the EGR is bad and either needs replaced or removed.

No, if it does that means the EGR solenoid is sticking allowing vacuum to the EGR valve at idle. Very common problem.
Or, in laymens terms "bad".
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1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline PromiseKeeper

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Re: engine vibration
« Reply #10 on: May 26, 2011, 09:12:05 pm »
Vile can correct me if I'm wrong on this. You should be able to take that vacuum line off of the EGR and suck on it enough to tell if the diaphragm in the EGR is working. I had one once that was stuck and when I did this it freed up and worked correctly again.
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Offline VileZambonie

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Re: engine vibration
« Reply #11 on: May 26, 2011, 11:09:58 pm »
Quote from: 1979C20 on May 26, 2011, 03:02:53 pm
Quote from: VileZambonie on May 26, 2011, 01:10:18 pm
Quote from: 1979C20 on May 26, 2011, 12:26:39 am
Quote from: the_legend_1981 on May 25, 2011, 10:04:05 pm
what if it does? leave it unplugged?
If it does than than the EGR is bad and either needs replaced or removed.

No, if it does that means the EGR solenoid is sticking allowing vacuum to the EGR valve at idle. Very common problem.
Or, in laymens terms "bad".

No, the EGR Solenoid would be "bad" not the EGR valve
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Offline Low87

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Re: engine vibration
« Reply #12 on: May 27, 2011, 08:20:55 am »
I took the line off the EGR valve last night and it didn't seem to make a difference.  When I went to put it back in place, I noticed there are two nipples coming off the back of it.  I plugged the line into the other one (I think) and the engine smoothed out. 
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Offline 1979C20

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Re: engine vibration
« Reply #13 on: May 27, 2011, 03:40:39 pm »
When you unplug the hose to the egr, you have to plug the hose with a screw, bolt, thumb otherwise there will be a vacuum leak.
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1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline VileZambonie

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Re: engine vibration
« Reply #14 on: May 27, 2011, 09:09:38 pm »
No, there should be NO vacuum to the EGR valve. If you unplug the vaccum hose and there's vacuum present, there's your problem.
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