I'm new to diy mechanics. pls help me identify this sound

[Holly]

Hey everyone,

I picked up this terck back in November, it's my daily. It's got a lot of work that needs done, but here's the 2 most obvious issues (and please let me know if I should cease driving it until these are addressed):

- timing. It's set to factory, but I think I need to adjust it per the pulsating noise. I don't know if I should lower or raise it? I've never personally messed with timing; Jhanek set it to factory for me but I think that's what caused the pulsating noise

- the shut down! This thing keeps firing sometimes up to like 10 seconds after I turn it off. I just replaced the fuel and air filter. Everything I read online says it could be one of like a hundred issues, so I wanted to check with you all first before I tear the thing apart.

My car experience is limited to doing my own general maintenance since forever, but not until this car did I decided I wanted to start taking things apart and learning how to fix. So, please talk to me like a kindergartender, this will all be new to me

Here's a video:
https://drive.google.com/file/d/1_yW9Rq ... sp=sharing

[Petros]

hI Holly, got you covered! welcome.

pulsating noise can be a number of things, we will need more information. if the idle speed hunts up and down in a cyclic way, that is indication of a small vacuum leak. check all of the vacuum lines for correct routing (use the vac diagram under your hood, or if hard to read, find it in the factory service manual, FSM, available for free down load elsewhere on this site). just follow each vac line from end to end with your finger using the vac diagram to verify it is routed correctly, both ends are connected and the line is not cracked or damaged. usually you will find the source and fix it. you can also use a can of starting fluid spray, with it at idle you spray small puffs of the fluid around the base of the carb, and at all the vac lines. if there is a vac leak you will hear the engine speed up when you puff starting fluid right at it, as you spray it at various locations around the carb and intake manifold. finding the leak is almost always more time consuming than fixing it. but none of this takes very long, you should be able to check all the lines and look for leaks in under half an hour. a bit more if you take your time with the vac diagram.

spark timing: the factory setting of 5 degress BTDC is for emissions, not good for the engine or for good running and better economy. set it at about 10 deg BTDC, using a timing light per the FSM (vac advance on the distributor disconnected and capped off). you can do this by ear, loosen the pinch bolt on the distributor so it is finger tight, but you can still turn the distributor. with the engine running, turn the distributor so you can hear the engine speed up a little. test drive it, if you get ping or knock with hard acceleration (a kind of crackling noise from inside the engine), back it off a little. the most advance you can run without ping or preignision, that is best for the engine and fuel economy. running it at the factory 5 deg will cause a much hotter exhaust that will make the internal parts, namely the exhaust valves, to run hot. if they overheat it can break off inside the engine and cause a lot of damage (you will trash the engine). that is not common, but I have seen it a number of times. the 10 or 12 degree advance will have cooler exhaust (the fuel burns more completely before the exhaust valves opens). You will not put more pollution out, and trashing your engine will require more resources to fix it than what ever idiotic idea the feds had when they mandated this by law back in the 1980s (note, none of the newer cars have such retarded timing settings).

The engine "run on" after you turn off the ignition: this comes from overheated combustion, also known as "dieseling" because it runs without spark like a diesel engine. the advanced timing can fix that by bringing down the exhaust temp, and/or finding and fixing the vac leak (if you have one) will stop it. a vac leak causes it to run too lean, and that causes it to run hot. if that does not fix it, you can stop it by getting in the habit of putting the car in gear (clutch in) before you turn it off, and let the clutch out at the same time. it is not good to allow it to diesel, it can damage the internal parts (exhaust valves, head gasket, rings, etc).

sounds like you have symptoms of a vac leak, if I understand what you mean by "pulsating noise" as the idle speed hunts up and down in a cyclic way. and the run-on or dieseling is also a sign of a vac leak.

good luck.

[ALiveSR5]

My car experience is limited ... not until this car did I decided I wanted to start taking things apart and learning how to fix.

You apparently have the willingness and aptitude and a Tercel is a great (and forgiving) car for learning this stuff.

Did you get the radiator cooling fan working properly, after getting the timing belt project done? The engine temperature may play a small role in the issues that you described but an engine that runs too hot or too cool could make it run sub-optimally.

Petros is a good guy to learn from - I would have liked to have had him mentor me, years ago. Follow his instructions and read his posts and you will get the hang of this pretty fast.

My Tercel dieseled like you described, mostly in really cold weather, but I did not know about changing the timing, as Petros described. Lucas fuel treatment and a periodic hard run (to blow out the carbon) helped some but never fully resolved the issue. In cool to warm weather, it ran fine, otherwise. I hope that you successfully resolve the issues with yours.

Cheers

[Holly]

I hired a mobile mechanic to come to my house and teach me to do the timing belt process (rather than paying him to complete the project) though I did have to borrow a few tools.

100 bucks for a new window of knowledge from a licensed mechanic? Count me in. Youtube is a great teacher but most of those videos require a general baseline of knowledge that I maybe have only 25% of.

I'm going to check my vacuums today, since it's finally not raining, but shutting down my car with the clutch in has mostly worked.

[xirdneh]

If carb is stock check the primary solenoid. It should click when electricity is applied directly. Its located on back of carb on passenger side.
There is a hose from bottom of carb on driverside that connects under air filter housing. Make sure its hooked up.