Strange happenings

Car has been running great. Went out tonight and noticed two issues:

Running a 1915 with Dual Weber 34 ICT, recently intstalled new fuel pump.

1. She seemed 'Heavy'...car was responsive, no popping, not sluggish, just took longer to move. Highway driving and no hesitation....just heavy. (I can hear the heavy jokes now)

2. Noticed fuel mileage was brutal....dont have the final numbers yet but it was eating gas...somewhere in the 15-17 range.

No leaks, no smell of fuel, just those two symptons. Did a search and it looks like a variety of possible issues.....Valves, jets, fuel filters....will be looking tomorrow to get this sorted by the weekend.

Any thoughts?

Justin

Brakes dragging ??
Alan

Mechanical fuel pump with bad diaphram leaking into crank case and wrong size push rod? Clutch worn out and starting to slip? Lower octane Summer gas mix with more ethanol?

I'm going with brakes. I know I've driven more than once with the e-brake on as I don't have a lot of travel. Fully engaged is only up a couple of clicks on mine, so it's easy to miss.

Lane, I'm glad you admitted that, me too :-)

It's my understanding that those carbs (and others) are VERY sensitive to fuel pressure. It should be 3 to 4 lbs. Anything more may be keeping the needle open from the seat causing a very rich condition which would cause the symptoms you describe.
Doug

Justin, if your brakes are in specifications and your e-brake isn't maladjusted, I'd recommend you price out the best deal you can get on a Facet 3-lb. fuel pump, and install a filter ahead of it.

Bogging and heaviness are symptoms which (as has already been said) sound like an over-pressure problem -- most especially if there's no additional associated noise.

I put my Facet pump up on one-inch rubber isolators so I wouldn't hear it hammering through the chassis, and it's been Old Reliable for me since the day I installed it. I got it off the shelf at a speed shop.

Webers like good volume, but low pressure. Make sure you are over-pressuring the fuel system.

When a car runs smooth, but seems to just be kind of wussy, always start with the plugs. If you are real fat and carboned up, your power just goes away right up to the point to where it decides to start missing or quit. If the plugs are fine, move on to timin (check for advance at RPM), move onto fuel delivery, etc.

Check everything. Sometimes it's something really foolish that makes magic HP disappear - like the throttle isn't opening the whole way.

That one, like the dragging brake, will really make you go DOH!!!!

angela

Hey before you go to crazy checking other things the first thing you should check is to make sure that the new fuel pump you just put on it the same as the one you took off. There are two different stock mechanical fuel pumps that look alike. The difference is the push rod legnth. One of the pumps has the foot (the thing inside that rides on top of the push rod and looks kind of like a rocker arm) up further inside the pump then the other. When these pumps are mixxed up it can cause your exact symptom. Good luck.

Still tinkering but the fuel pump that I recently installed was the rotary pump from CB (3.5lbs). http://www.cbperformance.com/catalog.asp?ProductID=577

I will double check it was not the other one..... That would suck.

JK

Yours is electric, Justin. The one that Kevin is referring to is the mechanical pump.

angela

Oops, thought you had replaced the stock mechanical fuel pump.

As for you electrical one, where did you mount it? If it is in bad spot for it's design it could also cause the same issues.

Also did you install the carbs at the same time? If so it could simply be a thing where you are not getting full throttle.

One thing to always remember and not many people do. Is when you make a change or do some type of adjustment, tune up or ???? and the car has a new symptom after doing said thing. GO back and double check what you did, 9 out of 10 times it's something that you did or effected while doing it.

Just to verify, they are Weber carbs? I had an issue with the Empi knock offs of Weber 34's where the needle and/or seat wasn't stopping the flow of fuel (you could see fuel flowing onto the carb throat when you looked down into it). Replaced the affected carb and ALL's well now.
Doug

Ok...have isolated the issue...thanks for all your feed back....

It was brake drag. I got the car on the lift and with the e-brake not engaged found that the cable going to the passenger rear wheel was extrmeley tight. The rubber plugs in that drum were also melted. The drivers side rear cable was slack, exacaty how it should be.

The shop will taking the wheel off today for examination and we will determine the extent of the damage. Trying to figure out how this happened and how I prevent it from happneing again....did I go to long in between drum brake adjustments? Did I not notice something I should have with the e-brake? Also have a small amount of transaxle fluid leaking down that side onto the drum. If it is soaked, is replacement of the drum needed? Anything else I need to be aware of with this type of leak....I am hoping it is just overfilled and not something else.

Thanks for all your feedback...on a good note the engine is dialed in and running like a champ.

JK

If it melted the rubber plugs - the bearing leak is from deterioration of the rubber seal. Unless the drum is crazed, burnt blue or out of round it should be ok. I'd suspect the brake cylinder is affected and should be replaced (or rebuilt with new rubber pieces). As brakes wear the shoes get smaller --- so looser not tighter. My guess is a shoe holding spring came loose (retainer broke) or they were seated improperly sometime in the past.

When you say the cable is tight, do you mean the inner cable or outer sheath? If the inner, check that the cable hasn't frayed and is hung up on the guide tube in the chassis tunnel. Disconnect both cables at the drums and pull out the pivot pin on the brake handle so you can pull the handle and cables far enough forward to inspect.