1958 fuel injection

[Bruce W.]

Hey Guys,My 58 fuelie is running to rich. actually burns my eyes if running for short while in my garage you an also smell the raw fuel when driving. I am running racing fuel is that the problem? How do I lean it out?thanks. Bruce

[Richard T.]

Re: 1958 fuel injection

The first thing I would do is check the cranking signal valve. Sounds like it's leaking.

[Jim L.]

Re: 1958 fuel injection

The first thing I would do is check the cranking signal valve. Sounds like it's leaking.

Assuming your '58 has a 4900 FI unit, if this problem just started and previously the engine ran fine, then the Cranking Signal Valve is the first thing I would check also.

If, for some reason, your '58 has a 4800 unit and this problem just started, then I'd suspect the starting fuel valve isn't closing properly. Fixing this problem isn't a job for a Do-It-Yourselfer, though.

Either way, no need to go fiddling with any of the adjustments!!!

Jim

[Bruce W.]

Re: 1958 fuel injection

Jim, thanks for the input. This car runs great ,starts perfectly. was wondering if this strong smell could be because I run racing fuel in it. The unit was rebuilt a few years ago by a pro It ran this way from the day I got.Bruce

[Jim L.]

Re: 1958 fuel injection

Jim, thanks for the input. This car runs great ,starts perfectly. was wondering if this strong smell could be because I run racing fuel in it. The unit was rebuilt a few years ago by a pro It ran this way from the day I got.Bruce

What model FI unit is it? And what did the pro who rebuilt it have to say about the problem?

BTW, running racing gas won't make it idle too rich. In fact there is almost zero effect on air/fuel ratio as a result of using it.

I don't use racing gas because it makes my wallet run too lean.

Jim

[Bruce W.]

Re: 1958 fuel injection

Jim, It is a 4900r. racing fuel prevents the gas from percolating when it is hot outside. Haven't spoken to the rebuilder since I thought this would be a simple adjustment.Bruce

[Jim L.]

Re: 1958 fuel injection

Can you characterize the rich nature of the FI unit? That is, do you see black smoke coming out the tail pipes or do you know it's rich only because you can smell it? Do you have trouble keeping the engine running after it warms up?

If large amounts of black smoke, I'd suspect the Cranking Signal Valve, as previously noted.

Another possibility is that the Cold Enrichment mechanism isn't turning off after a few minutes of run time. The definitive way to know if it's turning off is to look at the ratio lever, which should be on the Power Stop for a couple of minutes after a cold start and the transition to the Economy Stop when Cold Enrichment turns off.

If you can rule out the Cranking Signal Valve and the Cold Enrichment mechanism, then try adjusting the idle mixture screw. This is the small, spring loaded screw on the rear of the Air Meter mounting flange. "Tune" this screw setting for highest and smoothest idle.

Jim