1981 Spider Turbo Won't Run

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mcnamajp

1981 Spider Turbo Won't Run

Post by mcnamajp »

I have a 1981 Fiat Spider Turbo. I've owned it since new. I'm having trouble

getting it to run properly since it's been sitting for several years. I

stopped driving it a while back because it would start and run properly but

after 30 minutes of running it would shut off and after cooling 45 minutes

would then restart and run normally for a shorter period of time. Not even a

hint of starting during this cool down period and then it would just fire

fine. So I parked the car thinking I'd get back to it soon. A few years

passed and I would start and drive it periodically but I started having

additional problems - now it has stopped running properly at all - first it

was down on power (would hardly go while driving except in boost mode),

backfiring and turning the exhaust manifold red even at idle because it was

running so rich? or perhaps because the waste gate was stuck - it seemed to

be boosting abnormally quickly. So I replaced the ignition module and the

the distributor pick-up. Now it turns over and starts to start but then

quits. When the car was new the inlet air hose came off the MAF box once and

the car would start to start and then quit and it behaves like this now.

Reading elsewhere online I came across the suggestion to disconnect the

electrical connection on the mass airflow sensor and the computer would go

into a fault mode of running indicating the MAF was bad. Is this true of

this car given that I believe the flapper in the MAF box triggers the fuel

pump or could this even damage the ignition computer? If I disconnect the

electical connection to the MAF sensor should I also pull the hose off the

air box so a backfire doesn't hit and damage the flapper in the MAF air box.

Wanted to get some advice before proceding. CAn anyone tell me how to

diagnose the MAF sensor for fault?
Thanks!
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seabeelt
Patron 2019
Patron 2019
Posts: 1614
Joined: Tue Feb 19, 2008 4:22 pm
Your car is a: Fiat Spider - 1971 BS1
Location: Tiverton, RI

Re: 1981 Spider Turbo Won't Run

Post by seabeelt »

I believe Brad Artique has posted the FI troubleshooting guide. I think this is the link; http://www.gomog.com/allmorgan/FiatL-Jetronic.pdf
Michael and Deborah Williamson
1971 Spider -Tropie’ - w screaming IDFs
1971 Spider - Vesper -scrapped
1979 Spider - Seraphina - our son's car now sold
1972 Spider - Tortellini- our son's current
rlux4
Patron 2022
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Posts: 4211
Joined: Thu Jan 10, 2008 8:32 pm
Your car is a: 1982 2000 Spider
Location: Granite Falls, Wa

Re: 1981 Spider Turbo Won't Run

Post by rlux4 »

Not sure where to find it, but there are resistance measurements that could be checked on the output of the sweep arm fo the AFM. You may be able to find these with an internet search. You're right about the fuel pump needing a signal from the AFM to run but a while back there was a post about one of the guys here who said his car ran with it disconnected. I'm puzzled how this happens though. It would have to be a default mode circuit in the ECU.
The easiest way to diagnose a bad AFM is to use a known good one in it's place. Where are you located? Could be someone in your area who has a spare you could use to do this.
Just FYI, the L-jetronic system on ours cars don't measure mass air (MAF), they measure air flow; air flow meter (AFM).
Ron
Ron Luxmore
rlux2n2@gmail.com
'82 2000 Spider: after 26 years between Spiders.
So Cal Mark

Re: 1981 Spider Turbo Won't Run

Post by So Cal Mark »

your situation has most likely been agravated by letting the car sit for years. I'm sure your injectors are sticky and restricted due to varnish. The pump can run with the afm disconnected if the switch inside the afm is misadjusted or if the flap is sticking. If the exhaust is getting red hot you may have a seriously out-of-tune situation or a plugged catalyst
mcnamajp

Re: 1981 Spider Turbo Won't Run

Post by mcnamajp »

Thank you all for the advice especially the FI troubleshooting guide - seabeelt. I have a lot to look at now I'll post back when I know more.
Thanks Again!
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