i have an eg with a b18b swap..

i have some crazy vibrations, at idle, under throttle etc, it has some smooth spots in the rpm range but in general it vibrates a lot

ive visually looked at all my mounts and they look alright, placing my hand on the valve cover it doesnt shake much

car sat for a year and had some bad gas, after running it out and putting in new gas it has improved but still annoying

what could cause this?
thanks HT

PS. My old car had 75a poly mounts, and this is worse

 

Checked your timing? How about your plug wire order? Compression test? CEL work? On?

 

Cel works, no codes

Compression is great.

Firing order is good( doesn't feel like a miss, feels like the motor is bolted to the Frame with no mounts lol)

Timing MIGHT be off a tooth ( been battling a funky timing issue gonna check the physical timing this weekend)

Would this cause it to vibrate all the time?

 

Timing could make it run like ***, which could feel like strong vibrations. Double check your firing order, just to be sure.

 

it runs strong, but when adjusting the ignition timing, at full advance im not getting to the "3 marks" only about halfway

i will double check plug wires but like i said it runs great, so i wouldnt suspect a firing order issue

 

Is this a completely stock B18B1, with matching LS dizzy, cam gears, and crank hardware? If you can't get your ignition timing right, either your mechanical timing is off, or you have mismatched hardware somewhere.

 

bone stock ls everything..

We literally bought a wrecked dc4 and swapped the whole running gear

I think my belt is off a tooth, causing my ignition issues, it is a replacement dizzy but wa for the b18b motor

 

Double check the part # on the dizzy to be 100% sure, but yeah, sounds like you're off a tooth.

 

will do tonight, but the timing being off a tooth cause excessive vibration?

thanks for the help

 

Yes becuase it means your timing is off, and it's going to be assy

 

That's a yes/no/maybe thing. It can cause the problem, but until you fix it, we can't tell you for sure that it's causing the problem. It's free to fix, thus a good place to start.

 

i like the way you think lol
i will be digging into this sunday morning along with a valve cover gasket,oil change ill get back to you guys with my findings

 

If you can't adjust your ignition timing to line up with the three marks on the harmonic balancer, your mechanical timing is off a tooth or two, most likely.

 

mechanic timing, was spot on..

so on to other thoughts?

i have confirmed that my exhaust hangers are in good shape
and all 5 mounts are tight.. im at a loss..

 

Can you still not get the ignition timing to spec? Are you doing it correctly?

 

i have not played with the ignition timing again, ran out of time at the shop today,

correctly setting it wouuld be with a warmed up car..

jump service connector
attach timing light to plug wire one
shoot timing light at crank pulley
white mark being 0* red being 16*
advancing dizzy until it reaches the red mark
tighten bolts
double check
unjump connector
be done

correct?

 

if mechanical timing is off, that'll make it vibrate and run like a washing machine. i've also found a good, thorough valve lash adjustment cures a lot of engine vibration issues. if it's been a while since you adjusted the valves, it's worth a shot.

 

mechanical timing is spot on... but i havent touched the valves since i bought it.. hmmm

 

Any other ideas? This Is very annoying lol

 

do a valve adjustment

regardless of whether or not it will fix it you need to keep them adjusted within factory specs...it more important than you think.

 

Yeah I plan on it

I'm thinking my rear mount has to be bad.. It's the only one I can't see and I can't find any other cause

 

rear mount is your main mount... if it is bad you could look into getting a hasport or innovative rear mount... that one mount will help keep everything still and in place.. i personally use hasport complete kit.

 

I've been eyeballing the has port 70a kit

Which bushings are you running?

My motor thrashes around quite a bit on harder shifts so I'm thinking that mount may be my vibration

 

62a is ok...70a is a bit too stiff

 

really?

hmm i was running 70a innovatives on my h22 swapped cb7 and it wasnt bad..

b vibrate more?
or is because the b has those two lower funky mounts too?