Hey guys

For a number of years I've noticed that many people wrap their fuel rails in heat insulation type material. Two questions. 1. Does this help in any way? 2. I found this the other day and thought it might be interesting.

I only ask as well the fuel rail gets rather hot after a nice long drive (to the touch that is) and to me insulating it wouldn't be a bad idea.

Jan

Hmmm, I've heard of this. Seems to be common on the Z but I'm not sure why.

Early Zs and some later, mid-70s Zs, had issues with vapor lock. This was an attempt to minimize or eliminate the problem. It seemed to work on some cars, but not on others. I never had to use it on mine, and I don't know why....

Frank

He's talking about a z with EFI. There's really no reason to wrap the fuel rails on the EFI cars other than looks.

To echo D240's comment "mid-70s Zs, had issues with vapor lock" if you are not experiencing any VL symptoms it is just a cosmetic add-on.

I eliminated my '78's vapor lock issues with a shotgun approach. One aspect of the fix was wrapping my rails. The problems are gone, but I can't say how much the wrapping contributed to that. It's certainly cheap and easy to do, though. I used slit rubber hose, wrapped with silicone rubber tape like what you reference. The tape is a good product.

Here's a better source:

http://www.duluthtrading.com/search/searchresults/42042.aspx?feature=product_1&kw=silicone tape&processor=content

You'll use more than you think.

Edited February 11, 201114 yr by FastWoman

Once again, there is no functional need to wrap the fuel rail on the EFI cars but if it makes you feel better then...go ahead.

Edited February 11, 201114 yr by sblake01

Once again, there is no functional need to wrap the fuel rail on the EFI cars but if it makes you feel better then...go ahead.

I understand this mate and I've been told numerous times that EFI doesn't get vapor lock. Well apparently I'm getting it, but I think it has to do more with leaky devices (fuel pump check valve, CSV) rather than heat.

Is there any reason, other than price, that wrapping it would be a bad idea. I understand it doesn't need it but keeping anything cold in the engine bay is a good idea isn't it? Feel free to advise one way or the other.

Jan

No reason it would be a bad idea in that it wouldn't hurt anything. I never had those problems with any of the 4 Datsun/Nissan EFI cars I owned but I've always been pretty anal when it comes to keeping everythiing in proper working order on my vehicles. I've always fixed the actual problem rather than doing something to mask or compensate for the symptoms.

Edited February 11, 201114 yr by sblake01

No reason it would be a bad idea in that it wouldn't hurt anything. I never had those problems with any of the 4 Datsun/Nissan EFI cars I owned but I've always been pretty anal when it comes to keeping everythiing in proper working order on my vehicles. I've always fixed the actual problem rather than doing something to mask or compensate for the symptoms.

Well I'm fixing both the fuel pump and the CSV in the Z this weekend, so I'm taking your advice on this one.

Jan

Hmm that's funny, Nissan engineers found vapor lock to be enough of an issue that they added vents to the hood, and later a cooling fan on a timer to cool the injectors after driving a ZX.

The problem does exist and is very real. That said, it is highly dependent on fuel system condition and ambient temperatures. The fuel system should remain pressurized for enough time to pass peak engine bay temperature after parking. How long that is, is spelled out in the FSM. Common issues are micro leaks in the injector hoses, and sticky check valve at the fuel pump exit.

I have tried wrapping my original 76 rails and there is a difference, but not worth the effort. Hood vents are a much more effective solution.

All I'm saying is that I never had cause to wrap the fuel rail. There were no vents on the hood of my 810 or either of my 200SX's nor did any of them have cooling fans on the fuel railsand I never had the 'vapor lock' problem with any of them or my 280Z (though it did have hood vents). I'd agree that it's dependant on fuel system component condition but maybe not so much on ambient temps since I live in Southern California with it's 100+ degree summers. I guess I've got nothing else to say here. I tell of my experiences, which is all I can speak accurately on, and threre are those who want to refute what I say.