0Cunningham Motorsports

So i have a 65 327/375 fulie in my shop. Brought it in to replace the spark plugs and replace the gaskets on the fuel injection pump due to them being dry rotted and leaking. After replacing everything and getting it running the car is fouling out spark plugs everytime I start the car. Is there a way to lean the car out at idle? Theres an adjustment plate on the side of the throttle body that says lean and rich and I've tinkered with it but it doesnt seem to do any good. Any feed back would be great.

Thanks

MikeM

I realize you said it's a '65 model car. There should be a metal tag riveted to the left front of the plenum. It should have a serial number and model number stamped on it. The last three digits of the model number should read 380. Is this what you have or does it end in 375 or 375R?

I wouldn't tinker with any of those adjustments until you identify what you're working on and get some direction.

0Paul Ruggeri

Its been awhile since I worked on one, but I remember something about the injectors leaking when the engine was off. Seems like someone sold a solenoid that switched off the fuel to the injectors. Does the oil smell like there's gas in it.

MiguelsC2

I believe that was on early fuelie cars. I have heard of destroyed motors from those leaks.

jim lockwood

If that is a real '63 unit, it will have a mushroom shaped device, called a Cranking Signal Valve, on the front of the fuel meter, on the passenger side of the unit.

These gadgets can fail in truly creative ways. The most common failure is that it remains open when it shouldn't. When this happens, the engine will run excessively and uncontrollably rich.

If I was a betting man, I'd bet the Cranking Signal Valve on that unit has failed.

Jim

jim lockwood

You've heard correctly, but this is a problem that affects EVERY Rochester FI units ever made.

Later units did incorporate an internal design change that was intended to interrupt the siphon path. It works well..... right up to the moment that it fails.

It is a routine matter to add an external solenoid valve to the '62 and older units to control the siphoning problem. '63 and later units have a more elaborate fuel path that is difficult (but not impossible) to control with a single solenoid valve.

Jim

MikeM

Jim, he said the car is a '65 model. That's why I asked him to identify the model of the FI unit because it may be a '63/'64 375 or 375R unit with the CSV.

jim lockwood

Whoooops!!! Mike you are right and, geez, that'll teach me to read a posting without my glasses on.

To the OP, nothing I wrote about the overly-rich condition applies. Sorry!

Jim

0Cunningham Motorsports

The Part number ends in 380.

I dont smell fuel in the oil and it does have a solenoid for the fuel on it.

MikeM

If it was a 7375 or 7375R, I would have said the same thing Jim said above.

The solenoid on the 7380 unit is nothing more than a fuel primer (similar to a carb accelerator pump). If it doesn't work at all, it won't flood the engine. A cold engine won't even start without it working or the engine is primed manually.

Now, I'm only a long time tinkerer with these things, not an expert but it sounds to me like you have a fuel pressure problem. I believe the problem might be in the check valve in the spider or more likely something mechanical broken in the fuel meter. If you're lucky, it'll only be a stuck/damaged diaphragm.

The adjustment I think you were talking about making would be the ratio lever adjustment to control rich/lean for varying vacuum signals. The ratio lever should be against the rich stop to the rear of the car with the engine off and during cranking. As soon as the engine starts, see if the ratio lever swings forward against the lean stop at idle speed.

Check that or wait for a better answer.

MikeM

I just re-read your post. That "lean/rich plate" on the side of the throttle body is the choke adjustment. The only time you adjust that is to fine tune the choke blade position. Yes, it's common for the choke plate to bind up and cause plug fouling problems. You can remove the air intake hose and observe the choke plate for proper operation.

I'm assuming the car wasn't running right when it came into your shop?

jim lockwood

That there was a dry rotted gasket suggests this FI unit hasn't been used in a long time. True? If so, then some of the internal fuel-regulating mechanism could be stuck.

So, what do you know about the history of this unit?

Jim

wmf62

make sure the power/economy lever pulls back against the economy stop (the set screw closest to the diaphragm) when the engine is started (normal position with engine off is full rich (against the set screw closest to the center of the engine) when the engine is off as it is pushed against the power stop by a spring; engine vacuum pulls it back against the economy stop set screw when the engine is running.

if it doesn't pull back, the engine is running full rich at all times; so there is probably a hole/leak in that diaphragm.
Bill

DO NOT MESS WITH THESE SET SCREWS.......

CWPASADENA

I would suggest that this unit be looked at by a competant FI Person. If the car has not been run for several years, it may need to be gone thru. If things are stuck up internally, such as the check in the spyder and/or the syphon braker check in the fuel meter, the thing can leak fuel and hydraulic the engine.

With todays gas with alcohol in it, the old Buna-N seals will deterate if they have not already done so. You may want to consider a rebuild which includes Viton seals which are compatable with todays "Pump Gas".

Also, be sure the whole fuel system is CLEAN including the filters. The Rochester FI Units do not like dirty fuel.



Chris, CWPASADENA