Hey honda-tech, i have a 1989 civic si (d16a6) and when i initially start the car after not having been driven in a while, it starts, bogs down in revs almost to the point of stalling for about 4-10 seconds, and then runs fine. Any starts after that are perfectly fine, but the more time i let it sit, the longer it takes to start up.

My hypothesis on this deal is that i am getting oil into my spark plug valleys, causing the car to have to burn the oil off before normal driving conditions, hence why when i leave the car longer it's harder to start. Just replaced valve cover and plugs, made no difference. What are some other hypothesis that it could be or things i could check? I will be checking wet and dry compression when i get home, and seeing if any more oil is leaked into the spark plug valleys (as when i changed the plugs the old ones had a decent amount of oil on them.)

 

I had a similar problem with my car. I would start it cold and it would run rough and after it got warmed up it would start fine. It turned out to be a bad ecu that I bought used.

 

update: a little puff of smoke came out of the timing belt side of the valve cover when i got my bro to cold start the civic when i was in the bay...wtf? time to investigate

 

Blown head gasket?

 

smelled like oil smoke and there was no coolant in or around the valve cover or spark plug valleys, but i will be checking compression sometime today or tomorrow to figure it out....hopefully not

 

Update: radiator fan does not come on when the engine reaches operating temperature. Will be testing the ECT sensor and relay tomorrow, but i doubt that will be the issue.

Note: still bogs on startup, and before the vehicle is at full temp if I rev the engine up and let off throttle, it drops down to near stalling level (but never stalls) Could this be an issue to do with vacuum pressure?

 

Update: Compression tested
No oil added 1(101), 2(95), 3(100), 4(100)
Oil added 1(120), 2(115), 3(125), 4(105)

All numbers are in Psi, manual says that compression numbers are supposed to be 185 psi on a fresh engine...compression seems pretty low... (I did not hold throttle open so my numbers may be way off but are they at least accurate within range of each other? thats all i was really looking for...)

LMK if i should redo with WOT tomorrow, it just gives me another excuse to be out in the garage

 

The numbers are consistent, that's really what you're looking for.

 

Thats what i thought... ruled out head gasket and piston rings being the main problem for my startups

I will be uploading a video of the smoke it is making on cold starts...there is oil smoke coming from the VC on the cam gear side, is there any way the front main seal could be smoking? There is excess oil around the crank that has no dripping lead from up by the valve cover, so i know the front main is leaking oil, but is there any way it could smoke from there, or is it my valve cover what is producing the smoke on startups...

*video will be uploaded in a day or two when i have the time off school to do it, i will also be changing the water pump as it is leaking, and while i do that i will be doing the leaky front main seal, tensioner, and the timing belt.

*I am starting to think more and more the bad cold starts is due to an ECU problem, is there anything stopping me from testing the ecu with a PM5 ECU when i have a PM6? all the plugs are the same IIRC so it should work correct? From a MT '90 civic sedan to a MT '89 civic Si HB

 

*update* puffs of oil smoke are coming from just to the right of that bolt hole

 

Maybe a bad fuel injector leaking?

 

It's definitely oil smoke leaking, and the injectors aren't even close to there but is there any way that could cause it? If so could you explain...

that picture is just below the cam gear side of the valve cover, and just to the right is the timing belt. the smoke doesn't seem to be coming out of the valve cover, but it is definitely coming from there

 

on the picture i see the most smoke DIRECTLY half a mm under the timing belt upper cover female threaded hole. (that oily white part)

When the car is on the roads again i'm going to drive it down to my work (dealership) and crack the crank pulley bolt, and then retighten to bring back home and take off with my impact gun (my gun couldn't crack the rusted on bolt but once its broken free and retightened it will be no problem)
After that, i am going to take off the motor mount and lower timing cover and see whats up on that side of the engine, will update with any new info

Quick question for anyone reading... Is there a seal on the cam gear side of the camshaft that would leak oil?

 

yes...its called the cam gear seal lol....your compression numbers are low..honda engines are soposed to be around 170-180 stock,even for an american car that would be low....to me it sounds like your getting **** in the cylinder after you turned it off....my car is doin that right now and i did a leak down test and i have pressure escaping from every were...pull you oil cap while its running and see if u have exesive pressure in the crank case.if you do im betting that you need a new motor

 

Compression tests typically only tell a partial story - leak-down testing is preferred over a compression, but they work in tandem. Regardless a puff of smoke would indicate pressure - if it was from a seal and blow-by it would be continuous. Add this to your runability issue - we can assume the pressure is coming from the head gasket.

Also - we can gather from your compression numbers (I assume you ordered them wrong as #1 is closest to timing belt) that after adding oil, the compression didn't jump by the same percentage as the rest. Furthermore taking away from (even though they are worn) a worn piston ring problem in that cylinder. All signs point to a bad headgasket/cracked something which can be verified by a leak-down test.

What does your oil and coolant look/smell like?

 

compression numbers are probably low because i didn't do them at WOT but if that won't affect it then yes they are very low

I will try the oil cap method and see, will also be replacing PCV valve for good measure

I am going to be buying a leak down tester as soon as possible, i was using a compression tester because i had one and albeit very limited information about my engine, it was more than nothing at all.

I ordered number 1 as the one closest to the distributor so yes they are ordered wrong (will double check what i wrote down when i get home but i believe i ordered them from the distributor side

Oil and coolant are both still fully seperate, no oil in coolant and no coolant in oil, no sweet smoke or anything that would imply that i am losing coolant to combustion either...(i have a leaking water pump but that will be replaced as soon as i get the damn oil leaks fixed! haha)

****also have some new oil splatter on the IMF near injectors 1 and 2 (the two closest to the distributor they may be called 3 and 4) so i will be checking the status of my PCV to see if i am overpressurizing something.

washed my engine bay at work today so it is clean from any old oil, after driving a half an hour home from work i will be checking for where EXACTLY the leaks are coming from

thanks for the input everyone, by the end of this thread i will have a leak free well running d16, or no d16 at all

 

You really need to replace that valve cover gasket too. Goodluck with whatever you find while stripping it down.

 

already done. replaced the vcg, all the spark plug grommets, the 2 front and 2 rear crown nuts and their respective seals.

took off oil cap while engine was running and a large amount of air was puffing out of the oil filler hole, enough that it was spraying flecks of oil around my engine bay...more than normal by far

 

***replaced pcv and problem persists, but no oil is leaking anywhere in the car as of now and after the oil was cleaned off there is very little oil smoke from the exhaust for some reason, and none in the engine bay

however with every bit of good comes the bad
...
...
a new problem is here too!

When i accelerate WOT my enging pretty much stays at a consistent rpm and goes "dahdahdahdahdah"...could this be a slipped timing belt? it's either a slipped timing belt or it's an ecu problem now. It is completely fine revving it without load, at idle, and accelerating at maybe 1/4 throttle, but as soon as it passes 1/4 throttle this happens. i will take a video of it sometime today but i will change my timing belt, water pump, idler pulley, and front main seal soon. The timing belt looks cracked a bit so it is definitely time for a new one and i have all the parts to do it sitting in front of me, no reason not to tackle this today

replaced fuel filter to no avail, and will need to find someone with a FP test kit so i can test if i'm getting the fuel i need (covering all my bases right now)

I'm pretty much narrowing it down to timing belt slipping, or ECU malfunction. I will be doing the timing kit and will post results, and after that my only option is an ecu...anyone selling a PM6 ecu that is known to run please message me, bonus points if you are in the edmonton/calgary area of alberta!

 

If your timing belt was "slipping", then your engine would probably be destroyed... If it just skipped a tooth, then different story. If you check your engine - you will find the problem. What you are describing is more than excessive blow-by. Either your rings are absolutely gone or you have another problem.

 

When i say slipping i mean skipped a tooth, as in it is not where it should be at any given moment during operation. And i will be doing a leak-down test as soon as i can get ahold of a tester.

My oil issues are not really that prominent right now, i have a slight oil leak still but the majority of them are completely gone and haven't resurfaced as i drive the car. The car also for some reason smells less like burning oil, and does not smoke as much.

My main issue is that on WOT it bogs and thuds, yet when i accelerate 1/4 throttle i can get a linear increase in speed. As soon as i can test the ECU i will rule out my biggest guess as to whats wrong, after that being that my timing belt skipped a tooth, and thirdly that my rings are COMPLETELY shot



***Update: this is a picture of my cam gear with timing mark a few degrees off of the mark for TDC cyl 1 (cyl closest to cam gear)

 

It's hard to tell by the angle - but it just looks like you are 4.5* off (half a tooth) so just a stretched belt. Even if you are a tooth off - replace and readjust - go from there...

 

Will do, thanks for the help! Now to get the damn crank pulley bolt off

 

when doing the cam timing i didn't have any marks on my crank pulley (checked when it was off and there were NO colored marks visible) How should I go about timing the engine? I have the inner timing cover and camshaft pulley ready to be lined up i just need to get the bottom end aligned with the top end...how do i do this? Get cyl 1 to TDC then do camshaft timing as per usual? I'm getting frustrated right about now, or can someone tell me where the cam timing mark is in degrees in relation to the woodruff key inserted into the crankshaft pulley?

 

Take a wire brush or something of that nature and clean the rim of the entire crank pulley. The one you should focus on is the second one in from the timing cover. (Not where the belt sits but right next to it - on either side.) You need these marks to be there to set ignition timing - so if they have been lost to Mother Nature - you will need to make your own.

On a side note your crankshaft timing belt gear will have a line on it. Use this to line up with the arrow on the oil pump. Then put timing cover on, followed by the crank pulley; then use the timing tab on the cover to see where your TDC mark should be. You should have 3 marks about 1/8" apart and one around an inch away... so FOUR timing marks in total.