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Posted by: 19144jt Jun 17 2009, 06:30 PM

Got a 1975 914 1.8 that I am starting to restore with some updates (chrome bumpers etc.). The fuel injection still works for the most part but I have already got hot start problems and eventually want to do a big bore and maybe a performance cam. Weber carbs direct sells a dual Weber 40 idf kit complete for $640.

I'd like to hear the pros and cons of converting to the dual carbs. Tell me what you think guys!

JT

Posted by: Vacca Rabite Jun 17 2009, 06:52 PM

If you have working FI and don't want to rebuild the motor, stick with the FI.

The stock cam will work with carbs, but not all that well. Changing the cam means a full tear down of the engine.

Zach

Posted by: MBowman325 Jun 18 2009, 12:14 PM

Hot start issues are typically unrelated to FI. You can either keep a hammer with you, park facing downhill, try the hot start relay or replace the starter. (In order of my desired trail of fixes, last most desirable)

I've yet to have an issue with the L-Jet on my '75.

Posted by: 19144jt Jun 18 2009, 01:27 PM

I should have clarified "Hot start problems"

The problem I am having is definately FI related. The starter works great and the engine turns over just fine it just won't start when warm. Probably cold-start valve or some type of thermoswitch. Haven't had time to diagnose it yet. It is just very hard to justify spending $200-$300 on a FI part to make it work for a yaer or so until I get a motor built and have to go with carbs anyway...you know?

Posted by: jmill Jun 18 2009, 01:50 PM

Cons - you live in California. Carbs don't pass smog.

Posted by: Cupomeat Jun 18 2009, 02:27 PM

I am a big fan of sticking with the FI, especially the L-Jet, for a close to stock T4 motor.

You'll have a smooth running engine, with very little maintenance and great gas mileage and longevity of the engine.

You'll find that the carbs will need more adjustment than you'd expect and the gas mileage is never as good as FI. (This doesn't get into the CA laws, nor the cam issues that have already been brought up). The L-Jet will work fine with 96mm bore pistons, BTW. It is air flow dependant for the most part, so it compensates very well.

Find and fix the problem and you'll be happier in the long run.

And, I know, they don't look as cool as with Webers.

Posted by: Marty Yeoman Jun 18 2009, 02:43 PM

Fix your L-Jet.
You'll be happier in the long run.

Posted by: neil30076 Jun 18 2009, 02:59 PM

Don't have to on a 75 ( Yet) :-)

Posted by: gasman Jun 18 2009, 04:38 PM

The cold start valve and thermoswitch don't come into play with a warm engine..Correct me if i'm wrong, I think you have to have cold weather (below 35 degrees) for these to kick in....I would check fuel pressure with just "key on" dwell timing etc......

Posted by: Bartlett 914 Jun 18 2009, 04:58 PM

Just to add that a leaky injector could be a problem. Have them tested and cleaned. New ones are available. I replaced all 4 of mine last year. Autohausaz had them and they were on sale at that time.

Posted by: r_towle Jun 18 2009, 05:08 PM

Hot start is ignition and fuel related from what I have found.

On the ignition side...clean it all up, get new points, set the dwell and timing spot on and adjust your valves properly.
Remove and clean the distributor and re-grease the advance plates...they have 35 year old grease and they sieze up fully advanced when its hot...then its tough to start fully advanced.

On the fuel side, typically its time for a new fuel filter and check your fuel pressure when hot.

In CA, any change (FI to carbs) is not legal...yes you are not checked, but you could get a ticket if you find a knowledgable LEO.

Rich

Posted by: jkeyzer Jun 18 2009, 05:37 PM

If you know carbs and are willing to deal with setting them up, I'd say go for it. You're planning to modify the engine anyway, and the stock FI isn't going to cope with the changes you are planning.

An aggressive cam pretty much necessitates PEFI (like Megasquirt, see the other thread) or carbs.