81 Engine Misses or does it?

[Tango]

I just got my 81 Spider in late fall and have driven it less than 10 times probably so its all new to me. Nice night tonight, headed into town with it. As we got to a stoplight a guy pulled up beside and said "Nice car but it's got a miss you should get fixed. You're going to hurt that thing". I said I hadnt noticed, he replied that he was a mechanic and he could hear it. He'd been behind us up and down hills and starting and stopping for about 5 miles.

First off, it may be so. It does rythmically kind of shake when idling, slightly. and there is a rhythmic note to the exhaust, but it doesnt stumble or "miss a beat" that I can hear. I thought it was just supposed to sound like that. I don't notice any hesitation or backfiring, no fuel smell, black smoke, although I have not been impressed by the car's power, but then again, it is rated for less than my Vibe. Well, I'll look at the plugs tomorrow.

The main question: what about his comment that I am "going to hurt that thing". I mean, back in the day through ignorance or necessity, I have driven vehicles that basically bucked they were missing so bad, but should I ground the car while I check this out?

I have new plugs last fall, but no idea how old the dist cap and rotor are or the plug wires. I can get new plug wires at NAPA tomorrow I guess...

Any thoughts?

[TulsaSpider]

Sounds like he is trying to get some business. If these cars have a miss you will know it.

[brunorahl]

I get the impression it's your spare car. It probably sits most of the time. A tune-up would be a good start, along with the fuel filter and a jug of heavy duty fuel system cleaner. You're slight miss could be from running lean because of gummy injectors. It happens a lot.

[Tango]

I'll pick some up and put in a fresh tank of gas. This car has been a garage queen for at least the last 11 years through the two PO's. Thanks for the advice.

T

[Tango]

Well, I didnt know how old the distributor cap, rotor and HT wires were, so I got replacements. Then some discoveries were made:

1. I couldn't get the rotor off. One screw is slotted, no problem, the other is a hex head that I can't get a wrench on. I managed to loosen it a turn or two only. I tightened it back up for now until I see what is available for tight, tight access like that. Is there something made for this?

2. The wires on the magnetic pickup are almost totally gone! insulation missing everyhere and the conductors visible are green with corrosion. I wouldn't dare move it until I can get a replacement, I was surprised it still functions! I will order a replacement, but it is annoying since I just drove to Niagara Falls NY yesterday from Cambridge to pickup my shipment from IAP, so save freight and duty. Rats. If in fact there is a miss I suppose that could be the cause?

3. I don't think the vacuum advance works. I got someone else to rev the engine while I watched, and the rod from the vac module doesn't budge. If I push the associated plate gently inside the distributor I can see it move. I took off the vac hose and rev'd the engine and can feel vacuum in the hose, but when I have it in place on the module and rev it, no movement.

I don't mind trying my hand at replacing the magnetic pickup, it sounds fairly straightforward, but I would rather not take the whole distributor out to change the vac module, and it sounds like a challenge to replace in place. Maybe next winter while it is down for a while and I can sort things out. A lot of posters seem to say that the car will run fine with the vacuum hose plugged, other than a bit of mileage loss, which is of no concern.

Is there something else I should be looking at while I am up to this?

Advice welcome.

[So Cal Mark]

if the dist is oily inside, you're going to have to remove it and replace the lower seal. From my experience, pickups and vac advance units are yearly maintenance replacement items, so you might as well get used to doing that job.
Since vac units have gotten up into the $60-75 range, we've been modifying the mechanical advance and doing without the vacuum unit

[Tango]

No, no oil that I can see. On the contrary, things like the vacuum advance linkage seemed hung up. It's free now, but I still think the vac unit is pooched.

I am still struggling to get the rotor off with that stuck hex head screw with no access around it. I will have a magnetic pickup unit tomorrow. I was playing with the vacuum advance linkage once I freed it up and if it had been working the wires to the pickup would have failed long ago. That extra flexing was breaking them before my eyes.

In another thread, there is reference to a link from Manoa Matt (sp?) about how to install this and properly route the wires inside the distributor so that there is allowance for flex but not getting them in the way. The link didnt work for me, maybe the thread was too old?

[Burningmustard]

No, no oil that I can see. On the contrary, things like the vacuum advance linkage seemed hung up. It's free now, but I still think the vac unit is pooched.

I am still struggling to get the rotor off with that stuck hex head screw with no access around it. I will have a magnetic pickup unit tomorrow. I was playing with the vacuum advance linkage once I freed it up and if it had been working the wires to the pickup would have failed long ago. That extra flexing was breaking them before my eyes.

In another thread, there is reference to a link from Manoa Matt (sp?) about how to install this and properly route the wires inside the distributor so that there is allowance for flex but not getting them in the way. The link didnt work for me, maybe the thread was too old?

Tango - Did you get your new magnetic pickup unit installed? I have never done anything like this before and I will be attempting to install mine tomorrow. It looks pretty straight forward, but anything to do with timing scares me a little. Any tips?

Here is the thread on my problems
http://www.fiatspider.com/f08/viewtopic.php?f=3&t=9803

[Tango]

I was laid up part of the week with some minor surgery, so I hope to get to it tonight.

I have the rotor off finally and everything looks good. I am absolutely stunned that the car ran with the pickup wires the way they are. Now, after having moved them there is no way I would turn the key on until I replace them. Frayed bare conductors side by side.

The only tips I have are what I have been given here by others:
- the pickup has to have the correct gap between the tooth on the shaft and the metal mating part of the sensor. 0.020 to 0.024" I believe, to be measured with a non-magnetic tool.
- It seems there is a top and bottom for the magnetic pieces that sits under the pickup. Mine came with instructions and all it shows is a diagram warning you to face it the correct way. One side has a line inked across it.
- I think you need to be sure that he wires internal to the distributor don't interfere with anything even when flexed by the advance(s) in the distributor, that they are routed harmlessly.

I am going to turn my engine by hand until I line up one of the teeth on the distributor shaft with the current pickup, then away I go.

Disclaimer: I've never done this before either. Good luck. Seems straightforward.

Tomorrow I pick up or borrow a timing light as part of the overall tuneup, and just to see that I havent bumped anything off the mark. I dont see how this will grossly change the timing. We don't turn the dist housing and the new mag pickup can only vary slightly from where it is now.

[ga.spyder]

Very easy install,even for a novice mechanic.There is almost no chance of the dist. moving.Just check and make sure its tight.I changed the mag p/u today in 10 minutes ,and I am not a mechanic(believe me !!).I drove my 82 for 2 years with a non functioning vac advance.Finally replaced it and I honestly cant tell any difference. Good luck.

[Tango]

Good feedback, thanks. I am working on it right this minute, I just had to watch Philly beat Boston in the playoffs first. I have the pickup in place. There is much more wire provided on the replacement, so it doesn't lie as flat as on the original, but it seems stiff enough that I can loop it up slightly and it will rest against the inside surface of the dist cap well away from moving parts.

I watched your progress on the other thread. Great to hear that you have made progress and what a great forum.

Just a bit later: OK. done. Car started probably a bit quicker than before. Otherwise, it runs the same, no better no worse now with new cap, rotor, mag pickup, plugs and wires. It has a full tank of gas with injector cleaner in it, so now to let that do it's job and let's see where we are.

[Tango]

Well, I drove the car to work and back today (about 20km round trip). I felt that the car has a bit more pep since replacing everything from the mag pickup through to the plugs.

This evening sitting with my neighbour from a couple of doors up the road, who is a mechanic, and he said that he heard a miss also as I was pulling up the driveway. The car has a distinct "blub-blub-blub" sound as it idles or at low speed. But then he said "but I dont know how those cars normally sound". Well, that makes two of us. I just thought that is how Fiats sound. When driving along the road at anywhere from 2000 to over 4000 rpm, it never seems to hesitate or miss.

His suggestion was to double up the dose of fuel injector cleaner and see what that does.

He also said that I could quickly kill the catalytic converter if I don't fix it soon. But on the other hand if I don't run it, how do I give the injector cleaner a chance to work ??? I've put about 70 miles on it since adding the Gumout stuff.

T

[ga.spyder]

My car has a little burble at idle,has since I got it.I have removed the cat and am running straight to the muffler.The sound you describe is the same wayboth mine sound. It is so hard to tell,but it seems to me you dont really have a problem that is very serious.It starts, runs good,et...I have been dealing with a miss,and it is VERY noticeable.I vote drive it !! I did have a slight skip at idle,which cleared up with a simple valve adjustment last year.Good luck