82 fi auto hesitates when cold

[Nicketts]

My 82 hesitates noticeably when going from a cold start. Seems to be worsening. Takes about 5 cranks to start when cold from overnight. When warm, starts easy and runs great. Is vacuum leak most likely? Any other thoughts? I run 91 octane no ethanol, have put injector cleaner in last two tanks. Low miles (37,000) and I have all receipts from new to prove that. So a leak seems more likely...stuff dries out I guess. Any thoughts? Thanks.

[AFRetired]

A little light reading.

http://www.mirafiori.com/faq/fiatFI_may2002.pdf

[Nicketts]

Thanks pal. Will start with oxygen sensor and keep trying. "Light" reading!!!

[AFRetired]

O2 sensor should be your last choice, try the cold start injector, Aux Air Regulator, and the thermo-time switch first

[AFRetired]

Reading Brad's book is a great help, Ch 8 is Fuel Injection

http://www.fiatspider.com/f15/viewtopic ... an#p250549

http://www.lulu.com/shop/bradley-artigu ... 15692.html

[micbrody]

I vote for thermo-timing/CSI vs AAV

When cold, the thermo timing switch (TTS) energizes the cold start injector (CSI). This enriches fuel mixture when cold. The TTS stays energized until it hits a certain temperature. The heat supplied to TTS is combination of the engine oil temp and internal heat resistor, both of which deform a bi-metallic contact in the switch. Typically, depending on how cold the engine, this will energize CSI from a second to up to 8 seconds of CSI injection.
Based on the the fact that engine starts when warm, this could be explanation.
If you remove CSI, tape up hole in engine, and start when cold, you should see CSI squirt a little. If nothing , then either CSI clogged/broken; or TTS broken.
The AAV can also cause starting problem if it's stuck. Remove it; put in freezer, and look through it. Should have a fairly large triangular opening. Run it under hot water, the triangular opening should close. If nothing happens(no movement or no hole), it might be stuck with crud. Take brake cleaner and clean; follow it with soapy water. After dry, repeat freeze/heat cycle

[RRoller123]

+1 on all that. The AAV, CSI/TTS combo system, plus the Temp Sensor at the front head coolant "T" are all suspect, but easy to test! Just a minor correction: The TTS sits in engine coolant, not engine oil, to read temperature.

[micbrody]

RRoller123,

I did make the assumption it was oil temp; but not sure. Thanks for correcting. With that said, why did engineers put TTS is such a awkward place? Couldn't they have added it to coolant T? There is even a place for another probe there.

[RRoller123]

Ah! .... the mysteries of Italian automobile design..... But I guess (purely a guess) is that it is in the middle of the intake manifold to get the best estimate of starting temp of the intake mixture?

[Nicketts]

Thanks for help so far. Took AAR off and cleaned it. Seems to work. Next will test power to cold start injector from TTS. If powered, will remove CSI and test for proper spray. Both these are pricey to replace so hope can determine which. Plus, it seems near impossible to remove the TTS because of location. Printed and memorized Brads chapter on FI. Many thanks.

[RRoller123]

It might be easier to just remove the entire intake to get at the TTS. It is in a horrible location under there, hard to even touch it. May be visible and accessible from under the car, with some socket extensions?

[Nicketts]

Thanks everyone, especially rroller. I cleaned the contacts coming off the cold start injector, gently, with a tiny wire brush. Starts first crank when cold, and hesitation gone. Happy spider owner here! Just put in new carpet today. Looks nice.

[RRoller123]

We ALL love it when a plan comes together.

[Nicketts]

Just an update. Sometimes starts quick, sometimes not. Used dielectric grease on connector to CSI, but not convinced I'm always getting a good connection there. Has hesitated when cold most times, just missed a couple, when I had fiddled with that connector. Do they sell new connector plugs, and do you have to solder them on? Live the car, will post pic when I have the time.

[RRoller123]

AR and the other vendors have the Bosch connector plugs, with wire pigtails attached, that you solder to the existing wiring, IF the existing wiring is good. Check the continuity and sensors, from back at the ECU connector under the glovebox to be sure that the wiring elsewhere along the circuit is not the actual problem.

Pete