FI on a 1608

[FiatMorris]

I want to fit a fuel injection system from a 1980 2000 to a 1972 1608. Is the fact that the FI system will be mounted on an engine with 200 less CC’s and issue? Does the O2 sensor compensate for the displacement difference, or will it always be running a little rich? Any info from someone who has done this in the past will be appreciated.

Thanks,
Steve

[FiatMorris]

Quick correction. Yes I know it is really a 400 cc difference. Math is hard.

Steve

[kmead]

The nice thing about FI is it measures the amount of air actually being drawn into the engine and meters the fuel accordingly. As a result it doesn't really care if the engine is 400cc less than the other engine or at 5500 ft where the air is thinner.

An issue you might have could be the cams, the 1608 likely has a wilder cam set than the late FI cars. On the other hand they may be just fine.

The 1608 produced much of the same power as the later 2000, which means it moves nearly as much air and therefore burns a similar amount of fuel.

The 02 sensor helps keep it in the right range, going to a fully programmable solution would allow you to use a wideband sensor and a proper throttle position sensor rather than the flapper which would allow for the wilder cams.

[FiatMorris]

Karl, thanks for the info. Sounds like I should not encounter too much drama with the conversion.

Steve

[manoa matt]

Its always been my understanding that all North American spider camshafts have the same profiles, however the camshafts are indexed to the cam wheels differently which results in different cam timing.

Early smaller displacement engines produced the same power as later larger displacement engines as tighter emissions regulations strangled the later series engines.

[BrianAz]

Hi,
Sounds like a cool project. Some pointers:
1. It seems that you have all the parts from the 2000 F1 spider, so it should not be a problem to mount the airflow meter and the O2 sensor in the same position as in the 2000 spider. The airflow meter is mounted a long way from the intake manifold and it runs over the exhaust manifold which does'nt make a lot of sense when considering cold intake air for performance. It is the same in the Alfa spider 4 cyl engine from the same period. I guess that there was an issue with pulsations or something. Remember that airflow meters were in their infancy in the 80s and lack the technology of todays meters.
Mounting the O2 sensor approximately the same distance from the cylinders will avoid temperature (too hot or too cold) and incorrect A/F issues.

2. The air flow meter measures the air flowing through it. It does not account for flow from purge canister (I assume that you are NOT going to all the trouble of mounting a canister and control valve so you can forget that headache), blowby from the crankcase and internal EGR from cam overlap. However, the good news is that there are adaptation values in the software that account for A/F changes and these are "learned" from the O2 sensor values. The engine needs to be warm for these values to update so the engine might be lean or rich on first start up before these adaptation values are updated. Disconnecting the ECU or the battery will zero these values.

3. In the software there is a base injection value which is corrected by the airflow meter and the O2 sensor. This base injection value assumes a 2.0L engine so, on a 1600 it may be a bit rich at start up before the airflow meter comes on line.

4. Perhaps you could consider mounting a wide band A/F sensor near the O2 sensor so you know that everything is working as it should.

Good luck and let us know your progress,
Brian.

[Daniel]

A Simple way to adjust the mixture is take off the black plastic cap on the air flow meter and play
with the spring tension setting on the flap it's very simple and easy to do then glue it back on
once you have it set to your liking .