Engine Timing and Rough Idle

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mchalem89

Engine Timing and Rough Idle

Post by mchalem89 »

I have a dilemma that leads into a few issues with my 80 fuel injected spider. I changed the head gasket and i've never timed a car before. The car is hard to start and runs poorly when it's cold, after the car warms up to the point when the fan cycles on and off it runs reasonably well but just doesnt sound right. I have a feeling I didnt time the car right. When I put everything back together the timing mark on the crank needs to be at the top mark on the timing indictor to be at 0 degress BTDC. Can someone please confirm that I lined it up with the correct mark? The timing belt helper and the Fiat book I have seen to show the marks differently.

I feel like I need to go back and do this over again. After the car is warm and I shut it off and try to start it is still hard to start and runs rough for about a minute. I need to give it gas otherwise it will stall. Very similar to a cold start but not as bad. I couldn't line up the timing mark perfectly when I was timing it because the idle kept jumping between 850 and 1000 rpm's. Souldnt the mark line up every time? It would be a different reading at every rotation. I just need some guidance on trying to get this timed right then move on to the air regulator from there if need be.

Thanks for any help that you can give.
narfire
Posts: 3959
Joined: Sat Dec 27, 2008 2:14 am
Your car is a: 1980 124 spider
Location: Naramata B.C.

Re: Engine Timing and Rough Idle

Post by narfire »

Kinda two parts to this. Get the engine lined up to tdc #4. crank mark at the small pointer under the water pump. Next line up the holes on the cam wheels to the small raised rib found on the front of the cam towers. Remember the crank goes around twice to the once of the cam wheels. The holes could then be 180 deg out. Got that all sorted :D
If you still have the metal shields on,you won't be able to see the holes on the cams.

Next part is to have spark arrive at #4. Pop the top off the dist cap and see if there is a small "nick" in the body of the dist. If so get the rear part of the rotor to line up with that and you should be real close to the rotor lined up to strike #4 pin in the dist. cap. If not,have a look in the cap and see where the #4 pin is and turn the dist so the rotor is about to hit the pin.
Button it up and leave the 17 mm nut snug to stay put but able to move with a bit of effort. Give it a crank and if you've had enough installation fluid it should start. :P If you have a helper, have them twist the cap a bit while cranking.
Should note that while the cap is off,have a look at the elec. pick-up wires and make sure they are in good shape. They get brittle with time and break, stranding you. (have a spare in the trunk?)
Good luck
Chris
80 FI spider
72 work in progress
2017 Golf R ( APR Stg. 1)
2018 F350 crew long box
vandor
Posts: 3996
Joined: Sat May 23, 2009 1:23 pm
Your car is a: 1971 124 Spider
Location: Texas, USA

Re: Engine Timing and Rough Idle

Post by vandor »

narfire wrote:If you still have the metal shields on,you won't be able to see the holes on the cams.
IIRC there are rubber plugs you can remove so you can see the holes in the camwheels.
Csaba
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
mchalem89

Re: Engine Timing and Rough Idle

Post by mchalem89 »

Great Help! I think i got the first part down but I have a few questions. How would I know if my timing is off 180 degrees? Also, when setting it to 0 BTDC the little pointers on the crank that show 0 - 10 degrees is 0 at the top or botton because I made it where 0 was at the top pointer. Was this correct? What did you end up using on that 17mm nut? Its a real pain to loosen and tighten when the head is in the car. I will be posting so videos of a cold startup as well as idling because I need all the help and advice i can get with this.

Thanks!!!!
narfire
Posts: 3959
Joined: Sat Dec 27, 2008 2:14 am
Your car is a: 1980 124 spider
Location: Naramata B.C.

Re: Engine Timing and Rough Idle

Post by narfire »

mchalem89 wrote:How would I know if my timing is off 180 degrees
One would notice the holes on the cam wheels are nowhere to be seen when the crank mark is at the top/ first/small pointer . Remember don't try and move the engine backwards as the belt has a tendancy to slip then. I usually remove the spark plugs(3 anyway) and then pull on the alt/water pump belt to get everything all lined up.
mchalem89 wrote:What did you end up using on that 17mm nut?
I have sacrificed and old 17mm or was it the standard equivilant...anyway I cut one in half as I seemed to be doing this evolution a bit over the years changing heads,rebuilding engines ect. I've since purchased a set of stubby metrics.

Chris
80 FI spider
72 work in progress
2017 Golf R ( APR Stg. 1)
2018 F350 crew long box
rlux4
Patron 2022
Patron 2022
Posts: 4211
Joined: Thu Jan 10, 2008 8:32 pm
Your car is a: 1982 2000 Spider
Location: Granite Falls, Wa

Re: Engine Timing and Rough Idle

Post by rlux4 »

If your timing was off 180° it wouldn't run at all. You time the cams with the engine at TDC; 1 & 4 at the top of their stroke. #4 will be on the compression stroke. You time the ignition to 10° BTDC. Once you've got the engine running use a timing light to set the dist. to fire on that mark by rotating the dist. a little at a time. For the hold down bolt on the dist. a crows foot open end wrench with a 1/2" drive end on it for a ratchet works great.
Ron
Ron Luxmore
rlux2n2@gmail.com
'82 2000 Spider: after 26 years between Spiders.
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