Gasoline additive for desert climate..........

[richard1]

I remember gasoline additive were added some years ago for desert climate states. Here in Nevada, they stopped this year or a year a go and vapor lock is becoming a more serious problem than last year and we are not even in the 115F of the summer.

I have an electric fuel pump, filters are replaced twice a year, engine is properly tuned and there is nothing else I can do for a full original vintage Z.

I have the dealer installed A/C fully restored a couple of years ago blowing accordingly to specs, an auxiliary electric fan to cool the condenser which maintains the air at the dash outlet to 51F and on this side, I am happy to use the car as a comfortable daily driver if i want to.

The engine temperature is always in the middle of the gauge and never goes higher.

My question is......can I add some "supplement" to the poor gasoline quality that we have in my desert state to improve the vapor lock problem and excessive consumption in summer?

In other words, from about 20-22 MPG in mild climate, I drop down to about 14-16 MPG because of the evaporation problem.

My engine is very responsive early in the morning as supposed for a full tuned engine but sluggish in the afternoon because of this fuel starving problem.

Could octane boost solve the problem or what kind of additive could help to fix this issue?

Both fuel pumps are OK, filters brand new at last tune-up a month ago, carbs are fine tuned, ignition components replaced at tune-up time.

The problem is simply what kind of gas additive could solve the problem in a desert environment.

[psdenno]

How bad is your vapor lock problem? I live with similar temps here in Palm Springs but don't experience vapor lock on either the '71 Z or my air cooled '70 914-6.

Dennis

[deadflo]

Richard, I have similar thread here regarding increased reports of vapor lock in FI cars:

http://www.classiczcars.com/forums/showthread.php?threadid=38752

It seems to me that the increased use of ethanol in gas maybe creating the problem.

[Arne]

If ethanol is the issue, you may want to look for a station that sells what the boat crowd calls "the Clear", which here in Oregon is 92-93 octane without ethanol. Oregon now mandates 10% ethanol in motor vehicles, although cars over 25 years old are still allowed to use the clear if they can find it. Generally only available at stations near boating destinations here. Not very convenient.

Might be worth testing a tank, even if it's not convenient for all the time use.

[richard1]

Richard, I have similar thread here regarding increased reports of vapor lock in FI cars:

http://www.classiczcars.com/forums/showthread.php?threadid=38752

It seems to me that the increased use of ethanol in gas maybe creating the problem.

but it is mostly related to FI engines and not carb ones. As somebody reported in this tread, it may be related to ethanol in the gasoline or a lack of previous additives during summer.

Since the last three months I fill with Shell regular 87 and I have always use 87 octane no matter the brand. Higher octane doesn't make a difference.

In fact, I would associate vapor lock and evaporation/starving in the same category because it never happens in normal climatic condition below 90F

For example, here are some situations happening most of the time:

-Cool morning temperature below 90F.....engine fully warmed up....smooth idle, responsive acceleration, steady engine temperature, no starting problem after multiple shot down and restart (always we A/C on) and no needed use of the electric fuel pump.

-Afternoon temperature of 95F+....smooth idle at start up, responsive acceleration after engine warm up.......engine starving at about ten miles of freeway driving......engage electric fuel pump and everything coming back to normal. The engine temperature always normal. Exiting freeway......engine still idling fine at stop lights but with a tendency to drop 150 rpm. Shutting the engine for errands for 5 minutes..........slightly harder to start even with electric pump on and need to idle to higher RPM for engine to rev up due to starvation because it is obvious, gasoline evaporation has happened somewhere between the rear fuel pump and the carbs. Now the engine idles rough at 700 RPM and the electric pump works twice harder (I hear the pumping I never hear otherwise in normal condition) to feed gas to the mechanical pumps and carbs.

From there, the engine idles or breath harder......kicks up quickly at stop lights but not as responsive on heavy load and acceleration but still acceptable.

Yesterday, I made a test after exiting the freeway and going to an errand for only five minutes........I let the car running at idle (doors locked of course) with A/C, electric fan and fuel pump. When I came back, the engine was dead with all the aforementioned accessories still on and the electric pump still "pumping".

I restarted the engine without problem and left the parking lot.

My conclusion is this problem is only related to the gasoline and nothing else.

It is the reason I am looking to an additive that can help these engines to perform better in very hot climate because it is not a overheating problem....badly tuned engine or leaking fuel lines. Everything is perfect and carefully taken care of.

It is quite simply a fuel volatile evaporation problem and I don't believe to go higher octane level will even fix the problem.

Is there a lead additive available on the market?

it is the only option I could see to fix this problem in the three worst months we are going through and enjoy my classic as before in these summer months "day time"......never a problem in the evening in cooler temperature.

[Inf]

I haven't had the problems you mentioned yet, but it hasn't quite gotten that hot here (it will later this summer).

Lately everywhere I go just sells the 10% ethanol stuff. I'm not at all happy about this, since I know this is simply about keeping those massive corn farming government subsidies flowing. Same reason you have to look really hard to find food and drinks that aren't using high fructose corn syrup instead of real sugar.

[Gary in NJ]

The original poster asked about an additive. If ethanol is the problem, I'd highly recommend StarTron. It can be found at motorcycle shops, marine shops & good 'ol WalMart.

Here is a marketing paper that explains what StarTron does. http://www.starbrite.com/whatsnew/STAR%20BRITE%20ethanol%20page%20%282%297-24-06.pdf

I use this product in the 240Z and my motorcycles. I believe it works as advertised.

[Galaxybj]

I have experienced the same problem when things heat up here in the Albuquerque area. Runs great in the morning and when I start home. About 3/4 of the way home (7miles) it starts to as if it is running out of gas. I finally checked the float levels and they were low. Setting them properly helped some, but the issue is still their. I am game to try the additive mentioned - I hate not getting to drive her a couple days a week during the week due to never knowing when she will decide to start acting up.

[richard1]

The original poster asked about an additive. If ethanol is the problem, I'd highly recommend StarTron. It can be found at motorcycle shops, marine shops & good 'ol WalMart.

Here is a marketing paper that explains what StarTron does. http://www.starbrite.com/whatsnew/STAR%20BRITE%20ethanol%20page%20%282%297-24-06.pdf

I use this product in the 240Z and my motorcycles. I believe it works as advertised.

you have pin pointed the problem and I read all the info in your reference and more on the Starbrite website.

All the information make sense and I believe it will solve the problem.

The product is only available at marine shops and the Bass Pro Shop in Las Vegas at the Silverton Casino which is close to my office in my way back home. I will definitely drive the Z Monday with a forecast of 107F and put some of this additive right away to see what will be the difference when I will stop for some errands after about 15 miles of freeway driving.

I will keep you posted about the results.

[Jehannum]

I have experienced the same problem when things heat up here in the Albuquerque area. Runs great in the morning and when I start home. About 3/4 of the way home (7miles) it starts to as if it is running out of gas. I finally checked the float levels and they were low. Setting them properly helped some, but the issue is still their. I am game to try the additive mentioned - I hate not getting to drive her a couple days a week during the week due to never knowing when she will decide to start acting up.

No such issues on my end, and I'm also in Albuquerque.

I did have a fairly massive vacuum leak from a crumbling vac cap, but that's about the extent of my fuel/air issues.

[torker]

You might just try some Lucas gas treatment. Have you tried any additives yet?

Also the front mechanical pump may be causing some heat soak problems. You might try bypassing it and just run the rear electric. Are the fuel lines insulated?

Do you have an electric fan that you could run on a thermostat or timer so it will run for 5 or 10 min. after you shut it off?

[Pomorza]

I've used sta-bil in my dads boat as it had that same problem in hot weather. We ended up having to clean the carbies first as there was tons of gunk in there. But ever since that day we've used sta-bil and it seems to help.

Jan