Rhythmic Surge

Keep it on topic, it will make it easier to find what you need.
SouthwestSpider

Re: Rhythmic Surge

Post by SouthwestSpider »

Sounds good Brad - today I will find an O ring. I noticed that either Ace or Autozone have possible replacements. Viton O-rings. There isn't a standard size? I suppose it doesn't matter I have the darned idle screw with me.

Update:: for anyone interested - the size of the o-ring is 3/8 inch outside and 1/4 inch inside - ring thickness was 1/8th of an inch. I got two at Ace hardware for .25 cents each plus tax - a grand total of $.53 cents. It fit nicely over the idle screw without stretching too much- the next size up was loose.
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bradartigue
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Re: Rhythmic Surge

Post by bradartigue »

SouthwestSpider wrote:Sounds good Brad - today I will find an O ring. I noticed that either Ace or Autozone have possible replacements. Viton O-rings. There isn't a standard size? I suppose it doesn't matter I have the darned idle screw with me.

Update:: for anyone interested - the size of the o-ring is 3/8 inch outside and 1/4 inch inside - ring thickness was 1/8th of an inch. I got two at Ace hardware for .25 cents each plus tax - a grand total of $.53 cents. It fit nicely over the idle screw without stretching too much- the next size up was loose.

Has no one commented on much they enjoy the rhythmic surge?
SouthwestSpider

Re: Rhythmic Surge

Post by SouthwestSpider »

Sounds like a garage band.
SouthwestSpider

Re: Rhythmic Surge

Post by SouthwestSpider »

Well no joy on the O-ring solution. I still can't get the idle below 1200 - the surge is less but still there and the idle is rough. It revs, slows down, revs, slows down. Almost like a chugging, but at higher revolutions. The throttle stop screw doesn't even touch the throttle stop and it still runs at 1200. I rechecked the tps. I've cleaned the idle screw port which is snugged down since adjusting the idle is unnecessary when it runs at 1200 rpm.
Next ? I'm ready to try...
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bradartigue
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Re: Rhythmic Surge

Post by bradartigue »

SouthwestSpider wrote:Well no joy on the O-ring solution. I still can't get the idle below 1200 - the surge is less but still there and the idle is rough. It revs, slows down, revs, slows down. Almost like a chugging, but at higher revolutions. The throttle stop screw doesn't even touch the throttle stop and it still runs at 1200. I rechecked the tps. I've cleaned the idle screw port which is snugged down since adjusting the idle is unnecessary when it runs at 1200 rpm.
Next ? I'm ready to try...

Plug the AAR hose. If that thing is stuck open it will keep the idle high. See what happens when you do that. An internal leak (e.g. stuck open) wouldn't be detectable from the outside. Plug the distributor advance orifice with a little rubber cap. This usually won't produce that much of a speed change but worth eliminate it.

Then if that doesn't work -

Pull a plug, what color is it?

Did you spray propane or carb cleaner around the injectors to confirm that none of the seals were leaking?
SouthwestSpider

Re: Rhythmic Surge

Post by SouthwestSpider »

Will do! I haven't checked the fuel injector connections - will do that. I pulled the plugs* and they were black, except for #1 which was brown. The plugs were *Bosch and I've replaced them with NGKs (BPR6EGP - gaped to .28). Based on what was discussed on page two.

Thus far the only part I have not changed is the O2 sensor and based on what I've read - that shouldn't be replaced until the engine is running correctly.
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bradartigue
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Re: Rhythmic Surge

Post by bradartigue »

SouthwestSpider wrote:Will do! I haven't checked the fuel injector connections - will do that. I pulled the plugs* and they were black, except for #1 which was brown. The plugs were *Bosch and I've replaced them with NGKs (BPR6EGP - gaped to .28). Based on what was discussed on page two.

Thus far the only part I have not changed is the O2 sensor and based on what I've read - that shouldn't be replaced until the engine is running correctly.

#1 is lean and the other three are rich... Injector seal leaks come to mind. Leaking injectors come to mind.

But start with plugging that AAR line, then move on.
SouthwestSpider

Re: Rhythmic Surge

Post by SouthwestSpider »

The AAR plug didn't make a difference. If anything the entire engine sounds worse. I wonder if I should go back to square one and start again.
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divace73
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Re: Rhythmic Surge

Post by divace73 »

I remember reading (I think it was in Brad's article of the FI) that if the throttle position sensor/switch is not adjusted properly at idle it can cause hunting issue???? With the engine off you should hear a micro switch click as you open the throttle from idle or rest to cruise , then another click at WOT???
And check the resistance (and connection) of the water temp sensor in the front T piece as mentioned..
Just putting it out there....
Cheers David
-=1980 silver Fiat 124 Spider=-
If you want to see pics of my car (and other random stuff) >>click here<< OR
see my >>You tube channel<<
SouthwestSpider

Re: Rhythmic Surge

Post by SouthwestSpider »

Will do!

Brad - I'll start with the injectors and make certain they are seated correctly. Then reset the TPS, then ...?
Would there be anything wrong with the distributor, I discovered that one hold-down screw was loose so the cap was loose - your thought?

The engine sounds worse than it did after I changed the plugs.
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bradartigue
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Re: Rhythmic Surge

Post by bradartigue »

SouthwestSpider wrote:The AAR plug didn't make a difference. If anything the entire engine sounds worse. I wonder if I should go back to square one and start again.
Wait - wait - wait - wait - wait.

It sounds worse, eh? It may sound worse because you eliminated the issue and reduced the amount of air coming into the motor. Therefore you have to re-adjust the idle speed setting.

Start it, let it warm up (the fan will cycle two times), then set the timing, then set the idle speed. You have a shot here that the issue has been found. If it runs well after you do this then take the AAR out and clean it (fill it with electrical contact cleaner in a spray can from Radio Shack and let it dry out). Then reinstall the AAR.

On the other points, yes, you need to hold down that distributor cap. And yes the TPS can cause hunting.

Out of curiosity are you sure your plug leads go to the right plugs?
SouthwestSpider

Re: Rhythmic Surge

Post by SouthwestSpider »

Thanks - I'll get at it this evening.

Brad?
Do I reset the timing and idle speed with the AAR hose plugged? It's kind of hard to find the correct timing when the motor is running so poorly - but I'll try anything. I did try to open the idle screw while it was running so badly (curiosity only) and there was very minimal change.
So - at present - the AAR hose between AAR and the main hose is plugged, the AAR is still connected to the intake manifold, the throttle screw is not touching the throttle plate, there is slack in the throttle cable, the TPS is closed, the idle screw has a new O-ring and is snugged down, the main hose has no openings or cracks ... (did I miss anything?)

I will re-check the plug wires because anything is possible - but I'm fairly certain they are correct.

On the distributor cap - I tightened it down but I was just wondering if there would be something an experienced person would check (in the distributor) if they found a very loose screw on the distributor cap?
SouthwestSpider

Re: Rhythmic Surge

Post by SouthwestSpider »

Brad - is it possible that I have a bad injector? I pulled all four plugs and the 3 plug was slightly blackened, the rest were clean. I've cleaned and re-installed the AAR but since the engine runs so badly I couldn't work on the timing or idle. Would the surge effect be similar to one cylinder missing?
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Re: Rhythmic Surge

Post by rlux4 »

Pull your plug wires one at a time and notice how it affects the way the engine runs, when you pull one and it doesn't chage anything that's the one that's not firing. Then you just concentrate on it to see why. If your plugs are good you can swap wires from a plug that is firing and see if it works on the non firing cylinder. Are all four injectors clicking when they get pulse signal?
Ron
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'82 2000 Spider: after 26 years between Spiders.
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bradartigue
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Re: Rhythmic Surge

Post by bradartigue »

SouthwestSpider wrote:Brad - is it possible that I have a bad injector? I pulled all four plugs and the 3 plug was slightly blackened, the rest were clean. I've cleaned and re-installed the AAR but since the engine runs so badly I couldn't work on the timing or idle. Would the surge effect be similar to one cylinder missing?
Sure, it is possible.

AAR: Idle should have dropped with it plugged and the engine cold. Move on to something else. The only thing it should cause is a drop in idle speed with the engine cold, nothing else, and the car should run with it or not.

One black plug is an issue, you are either getting bad spark or too much fuel or inadequately sprayed fuel. Test the spark, then I would test the injectors. When doing so I would replace the seals, both of them, 2 per injector.
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