Hi, my dad and I have been working on a 96 Honda Accord 2.2L. We changed the timing belts, waterpump, and front balancing shaft seal. We just finished it up, or so we thought. We started the car up and it fired right up. Let it run for a minute and then revved the engine up fine but after releasing the gas the idle goes up and down from about a 900 to 1500 rpm. It kind of seems like a vacuum leak. Just want to know if it could be caused from the timing being off. Would really hate to do it all over but will do if I have to. Any suggestions or answers are greatly appreciated! Thanks
Wandering idle is generally not a timing issue. Your description of how it fired up and ran seems to confirm the timing is OK.
I’d be searching for an air leak between the MAF and the throttle body. Cleaning the throttle body may be overdue - a coincidental issue but easy to eliminate as the issue.
Possibly you created a vacuum leak by cracking a 23 year old hose? A vacuum gauge (old school tool!) will help you narrow it down.
Check the coolant level and make sure the coolant is bled properly. Those 90’s 4-banger Hondas got a wandering idle when the coolant was low or had air in it.
Thank-you so much! I bled the coolant and added more and it seemed to have worked. Still not a hundred percent sure but 99%. I stopped working on it last night after I had it running for a bit and didn’t tighten the bleeder all the way so lost some coolant after it was running great. Didn’t get this message until after I already went in and retimed everything. The cam pulley top dead center does not look Top Dead Center. It’s either half a notch too far or Too Short even after tightening the tensioner but I got it so close so I think everything is good. Just got to do the cooler again and put it back together later this week! Thank you so much for your help!
Good luck and please keep us informed. About the camshaft pulley: there are two raised marks 180 degrees apart. They should align with the top edge of the head; they give more precision than the top arrow on the pulley does.
Yup @shadowfax nailed it… Honda’s of that vintage do not tolerate any air in their cooling system. It throws the AIC (Air Idle Control) valve into a fit…and your idle will “hunt”. Glad you got it sorted out.
The 2.2L non-Vtec version of the engine uses an idle air bleed screw to allow the shop to set the idle rpm. If that screw is misadjusted from its nominal position it will make the idle unstable and wander.
Note: It appears the vtec version of the engine uses an idle adjusting screw too, so the same comment applies. there can be interplay between the idle rpm and base timing, so it may be necessary to adjust each several times before they are both correct.
Did you align both balance shafts?