ECU testing

[tima01864]

I have a problem with the throttle position switch. I set it properly and the engine cuts out, The engine idles good, Shut off the engine set the switch, Will not start. Back off the TPS all is good. From what I have read it leads to the ECU. I have tried three different switches.
Maybe I am wrong, I can't verify if it had been replaced at some point with an ebay unit. The ECU is correct for the vehicle and the wiring harness.

[spider2081]

I think the easiest test would be finding someone close to you with a fuel injected Spider that runs properly. Swap ECU's and see what happens.
I have seen ECU's that would not idle but above about 1500 rpm seemed ok. However I think most of the idle issues I've seen were related to the air flow sensor. Have you removed the black plastic cover and visually inspected the inside? Sometimes the flap stop gets bent and this allows the wiper to move past the end of the resistor PC board when the engine is not running. If that is the case I think the wipers range of adjustment could be off. To access the stop the AFS had to be separated from the air filter cover.

[RRoller123]

+1 2081, that was the case with my AFM, wiper running off the board. Sent it out to FI Corp and they did a full rebuild on it and the car runs better.

[tima01864]

I have the idle at 900 rpm, Only when I adjust the TPS does it cut out.
The AFM is newer, The PO bought it from Bruces Parts Bin, never been opened. The cap is off so the PO could pass emissions in NJ.
I got a hold of a used ECU but tested on a newly built Spider, Will try that.
Funny I have a used AFM from the PO, Numbered 0280202019, From what I can tell this is for model X 19.
Hard for me to know where the Owner previous to the guy i bought the car found the ECU, I don't think it is original to the 1983, This model started using the bariometric sensor, But it is early in production 3/83
See if the newer ECU makes any difference. I will return

[spider2081]

Funny I have a used AFM from the PO, Numbered 0280202019, From what I can tell this is for model X 19

I looked on the Midwest Bayless site and the AFM they show has the last 4 digits in the cover PN are 2024
There are a more than one AFM used on the Spiders. Some had a pop out valve to protect the flap if there was an intake backfire. Some have a wire that connects the output pin to the wiper. I don't know if the three type have different part numbers. I think the most common AFM used in a Spider is 0280 202 023

the ECU part number in my 81 Spider is 0 280 000 190
I think the ECU can have inputs that may or may not be used. The barometric could be in an ECU but not wired in a car.

[tima01864]

Thanks Spider2081, I like that about Midwest, They show part numbers for what they sell.

I found this post helpful http://www.hwww.fiatspider.com/f15/view ... on#p298005

[Zaffer]

I had similar issues with my ‘82. It actually turned out to be both the AFM and the ECU. I first had the AFM rebuilt, which got it running, though poorly and weird running issues ensued. I then had the ECU rebuilt and now it runs and idles very well. I believe part of the issue was also my FI wiring harness at the ECU as I found some wires with broken jackets that were contacting each other. I temporarily taped them and have a rebuilt harness, just haven’t installed it yet.

I used FIC in California for my rebuilds. They were quick and great to deal with, plus the pricing was good. I believe I paid around $200 for the AFM rebuild and $300 for the ECU rebuild. The AFM issues were the barn door was sticking AND the potentiometer contacts were worn in the unit itself. I don’t remember what the ECU issues were, but I figured it wouldn’t hurt due to the age of the equipment, and boy was I right!

[RRoller123]

Unfortunately, the Tech at FIC in CA that does the AFMs and the ECUs recently got sick and sadly, he has passed away. (This info is from direct telephone conversations with the company). Tim had his ECU out there and it needs to come back. It looks like my AFM last Winter was about the final one that got done. They are in a real jam trying to replace this fellow. Our wishes for Peace, and sympathy to his family.

Pete