81 starts & idles fine until warm...UPDATE

[giuliot60]

Hi again and thanks for all the previous help.

Haven't driven the Spider in almost 2 weeks and need to get her back on the road and enjoy this great weather. Miss her.

So after replacing my coolant temp sensor connector and cleaning my plugs that were black, the car starts and idles fine. When she starts to reach 190 degrees, she starts idling rough and will eventually stall out unless I'm on the throttle. I can rev her up, but get some slight exhaust popping sounds.

I'm using John Allen's online FI diagnosis, but need to get an ohm meter to check sensors.

So until I can test them, does anyone think it sounds like an O2 sensor, coolant temperature sensor? Should I just change them anyway?

Thanks!

[bradartigue]

It absolutely is not your oxygen sensor.

When the O2 sensor fails the ECU goes into a mode where the car runs pretty much exactly the same as if you had the sensor. You may be a tad rich or a tad lean, but not enough to impair driving. Most people drive around all the time with a bad O2 sensor and don't even know it.

Fix the car before you replace the O2 sensor or you will ruin the new one.

[giuliot60]

Thanks Brad. Use your stuff all the time too.

Do you think it could be the Coolant Temp Sensor then? She's been running great, then one day...

[4uall]

I know that when my wires were broken on my temp sensor in the T the car would run rough (if at all) at start up


Bosch connector (damaged) for temp sensor by itzebtze, on Flickr

[giuliot60]

It's kind of funny Jay. She's been running great. I took her out a couple of weeks ago with about an 1/8 of a tank of gas, about a mile into the ride she started hesitating like she was about to stall but didn't. Well a couple of hundred feet later she cleared up and was fine for the next 2-3 hours. The next day the same thing happened, so I took her back home.

The strange thing is that it started out as a hesitation/loss of power issue, but she idled fine. Right before and after the connector was replaced it has also become an idling issue once she warms up. It's frustrating.

[4uall]

hmmmm I would fill the tank right up, (i think you had mentioned about adding the Sea Foam in already), drive her around, could be a clog, in the fuel filter, tank mesh, gummed up FI I never had the same issue however, after 2 treatments of FI cleaner and some Sea Foam and Brad's idle setting info Fiona purrs like a hot Italian woman

[giuliot60]

Yes, and I just gave her a Sea Foam treatment through the brake vacuum line this morning. I'm sure it helped, but wasn't the cure.

Do you think it could be fuel related? I thought so too, but she runs great when I first start her up. So I'm thinking that she's getting fuel.

My plugs were black a couple of days ago, so I thought maybe the cold start injector. I unplugged it, but no significant difference.

I just need to go down the check list I guess

[giuliot60]

So my issue seems to have been resolved, at least for the time being.

What I did:

Sea Foam in gas tank, and a Sea Foam brake vacuum hose treatment.
Checked for cold start injector leak/drip. No apparent leak or drip into
manifold.
Removed, cleaned, and lubricated the AAR (Auxillary Air Regulator). Also cleaned
and greased AAR connection.
Pulled, cleaned, and reset Idle adjustment screw and idle.
Replaced air cleaner.
Slightly, and I mean slightly, adjusted Throttle Control sensor.
Dielectric greased injector connections.
Cleaned and dielectric greased coil module connection.
Slightly tightened the intake manifold cover.

Concerns: My pump was bypassed by the PO, and I can usually hear it hum when I
turn the key. Today it didn't always make a sound, so I'm not holding my breath.

[lanciahf]

My old Spider had the same symptoms as yours. Turned out to be the Coolant Temp Sensor. For a while I would start it then put a paper clip in the Coolant Temp Sensor connector so I could drive it around. I miss being 18.

[giuliot60]

Good to know. I'll keep a paper clip handy

I'm thinking that I should probably put all new FI sensors and dizzy parts, and keep these as back ups. Why wait for them to go bad at the wrong time.

[bradartigue]

Good to know. I'll keep a paper clip handy

I'm thinking that I should probably put all new FI sensors and dizzy parts, and keep these as back ups. Why wait for them to go bad at the wrong time.

Any 20+ year old sensor (well 30+ now) is past the point of failure. So it isn't a bad idea to replace it all, but I would recommend using Bosch parts. It would also serve you well to replace the FI connectors, which you can get new from Bosch via any Porsche parts place. I'm not sure if the FIAT vendors sell them. They are very easy to use and have a rubber cap. Absolutely stock looking and no weird splices required.

[giuliot60]

Thanks Brad.

The injector connectors looked clean when I popped them off and greased them, but I will look into replacing them since they probably aren't too expensive. The CTS connector was less the $6 from AR.

So Bosch everything, as much as possible?

What are your thoughts on Spark plug wires?

[bradartigue]

Thanks Brad.

The injector connectors looked clean when I popped them off and greased them, but I will look into replacing them since they probably aren't too expensive. The CTS connector was less the $6 from AR.

So Bosch everything, as much as possible?

What are your thoughts on Spark plug wires?

Another thread on this forum I am being berated for suggesting that you should use OEM, Bosch parts. However, I have plenty of evidence and numerous cars, FIAT and non-FIAT, that always seem to run forever with Bosch parts and run only for a few years with the aftermarket stuff. Bosch parts are available, expensive, and work for a very, very long time.

I'm sure AR is selling the same part I use, a Bosch made end connector for FI harnesses. One of the added bonuses of the new style connectors is you don't need a screwdriver to get them undone, the clip is long enough to press. Makes things much easier. If the connectors are good then i'm not sure I'd replace them, but they are old, in a very hot space, so it can't hurt. Make sure you put the right wire on the right side of each injector, easy enough to do - but some L-Jet harnesses aren't color coded. One wire at a time suffices. The connectors can be had with or without pre-wiring, and to be honest the ones without look much better because you don't have to splice them upstream. If you do have to splice then use bare butt connectors (no insulating plastic) and heat shrink them each to a wire. Looks professional and stock.

On plug wires, not sure it makes a difference so long as you use a decent quality; FIAT's Marelli ignition system doesn't require any equalization of the lines (whereas many cars, like Alfas, do). Whatever Csaba sold me the last few times seems to work fine, and I've used Bosch sets and they work fine. On my own car I have Cavis wires, which was a FIAT supplier and I think reoriginals sells them (I do not know if they are suited for electronic ignitions). Magnecore wires are great and I use them on another car, and you can buy them in black if you want to avoid the glitz factor of having yellow or red or blue wires.

[4uall]

This is what AR has


Bosch Ultra - Premium - 7mm Opti - Layer Mag Core by itzebtze, on Flickr

[bradartigue]

That is what we have on the 82.



Starts every time, one tiny little crank! (note stock appearance due to OEM parts)