Mechanics

PONTIAC FIERO ENGINE PROBLEM

1985 Pontiac Fiero

Adjusted valves, will not start now
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Juliesmith1
November 19, 2012.




Sure would be helpful to have some information. Why did you adjust the valves? How did you do it; engine running or off? Have you even tried backing them off and starting the engine?

Caradiodoc
Nov 19, 2012.
I heard a lot of noise from rocker arm cover, car ran rough, Removed covers and the rocker arms were very loose so loose they would move side ways. ( I just bought the car and previous owner said he rebuilt top half of motor) Brought No. 1 piston up and felt air coming from spark plug hole. Aligned timing mark to 0 degrees on timing tab. Followed Chilton manual adjusted rocker arm nut 1 1/2 turn after lash was removed, rotated engine 1 complete turn and finished up remaining rocker arms. Car would not start, repeated process this time adjusted nut 3/4 turn after lash was gone. Same results both times.

Tiny
Juliesmith1
Nov 19, 2012.
I think we can assume there's nothing else wrong mechanically with the engine. 1 1/2 turns sounds like too much. You also have to adjust the valves in four steps. Each half revolution insures one quarter of the valves will be closed at some point.

Try this instead because you don't even have to know the firing order. Loosen all the rocker arms, then snug them down just enough to remove the free play. Rotate the engine a half turn, then snug down only those that have obvious looseness. Turn the engine another half turn and do that again, then one more half turn. That will get all the valves close enough for the engine to run.

Fashion a splash shield out of cardboard to contain the oil that's going to spray around and make it run back into the head. Most people use the cardboard that comes with valve cover gaskets. Start the engine, then on the first valve, back the nut off until you hear the rocker arm clicking. Tighten the nut just until that clicking stops. Remember that setting. Tighten the nut 1/4 turn. You'll hear and feel the engine misfire but that will clear up in a few seconds as the lifter bleeds down to self adjust. You don't want to continue too fast because the valves need to hit the seats to dissipate its heat. Tighten the nut another 1/4 turn, then wait for the misfire to clear up. Keep on doing that until the misfire no longer clears up. Back the nut off just until the misfire clears up. Remember, you were counting the total number of turns from where you started. Back the nut off exactly half that total. That will place the lifter right in the middle of the range it can self-adjust to. Do that procedure for each valve.
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Caradiodoc
Nov 20, 2012.
I finally got the Fiero up and running 11/23/2012. Thank you SO much for all the time and help that you gave to me, is very appreciated!

Tiny
Juliesmith1
Nov 24, 2012.
You aren't going to believe this, heck am not sure I even do. The Fiero has an automatic trans and it won't shift out of first gear unless you let off the gas. Didn't used to do this before, please, any ideas on this one? The fluid level is fine, still red. I would look for vaccum leaks but aren't sure which hoses to check and where they are located.

Tiny
Juliesmith1
Nov 25, 2012.
First check for a vacuum hose that got disconnected. A leak in any vacuum hose will reduce vacuum to the vacuum modulator on the transmission. Lower vacuum from a leak is the same as lower vacuum from accelerating and tells the modulator valve to delay the up-shifts.

Check the vacuum hose at the modulator for wetness inside. If transmission fluid is there, the modulator valve is leaking and must be replaced. The valve could be sticking too.

Caradiodoc
Nov 25, 2012.
Just found a clip that hadn't gotten fastened back in place. Car is shifting fine at this time. Motor wise, is sounding better than ever before. Your help has been invaluable to me, thank you again so VERY MUCH! Let's hope all stays this well and don't need to bother you again. : -)

Tiny
Juliesmith1
Nov 26, 2012.
No bother. I'm assuming I'm talking with a girl, and I think that's cool. Two of my top students were girls and the guys had a lot of respect for them. I also enjoy helping people learn how to diagnose car problems. My specialty areas are Electrical, Steering, Suspension and Alignment, Brakes, and Engine Repair. I have lots of "Notes Pages" and worksheets I put together for my kids. Some don't make a lot of sense until you've sat in on the "class discussion" but if you can use any of that, let me know. I send them as attachments in MS Word to your private e-mail.

Caradiodoc
Nov 26, 2012.

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