Why 75-80 EFI fires?

[TJ Hopland]

The other day I got to wondering why were the 75-80 EFI equipped cars apparently more prone to fires than some other EFI cars?  Was it that there weren't any?   And by the time there was their rep just stuck?   

Thinking about the EFI system and that the failure was apparently age of the O rings sealing the injectors to the fuel rail I really don't see any reason that system would be worse than any other.    When other cars got multiport EFI the systems were basically the same as far as having an oring seal the injector to the fuel rail and fuel pressures were similar.   

Just the timeline is all I can think of since the Cadillac EFI system became a mid year 75 option and then standard on the Seville which was a reasonable seller for Cadillac so 76 put quite a few systems out there that were over 10 years old by the time anyone else sold any number of multiport systems which was later 80's.

I would imagine that there were changes to the o ring material so that your 10 year old Ford wasn't leaking fuel like a the Cad's apparently did at that age but presumably if you bought replacement seals for your Cad around that time too you got a longer life out of the next set.

Does anyone remember were there any issues with these cars when they were less than 10 years old?   Or did the leaks and fires really start later?    Was it something like only the first year or two then they changed the material?       

[Dave Shepherd]

I worked for Cadillac  during those years in NYC. Some of the dealers installed Fram marine type in line fuel filter/water separators. Poor hose quality and sloppy installations caused some fires I saw.

[TJ Hopland]

Any idea why the extra filters?   Was there an issue with clogging injectors?    Did you often see filter and dirty fuel issues with the carb cars at that time and in your area? 

[V63]

The issue was more o rings on injectors would fail and Discretely squirt HP fuel. It’s very critical the o rings get changed every 5 years

[bcroe]

Part of the problem is that there were so many components subject to
up to 40psi.  Get the fuel filter on badly and you will be trailing gasoline. 
Later with in tank only pumps and better filter mounts, the potential
issues are decreased. 

As for modern cars, I believe they are also more prone to fires (at a given
age), than the carb cars.  I often comment on all the burned spots I see on
the shoulder, nobody else seems to notice.  I did not see them in carb days. 
Bruce Roe

[The Tassie Devil(le)]

Can't say that I have seen an extra amount of 'Burn spots" on the roadsides, apart from the ones that are the result of car thieves/joy-riders trying to destroy evidence.

The only "abnormal" car fires I have seen were from vehicles that were retro-fitted with LP Gas, and still running on both Gas and Petrol, and the owner forgetting to occasionally switch back and forth to keep the carby from drying out.

Bruce.

[bcroe]

Can't say that I have seen an extra amount of 'Burn spots" on the roadsides, apart from the ones that are the result of car thieves/joy-riders trying to destroy evidence. Bruce.

I am impressed, that you can discern that much info from a black spot. 
Mostly the ones I see are along heavy traveled expressways.  Bruce Roe

[hornetball]

I think we have a lot more freedom to run old cars here in the USA.  Even more so than fuel injection, wiring and connectors deteriorate after 25 to 30 years, especially as aftermarket stereos and car alarms age.  In some German cars of the 90s, the wiring is actually designed to degrade!

[chrisntam]

I often comment on all the burned spots I see on the shoulder, nobody else seems to notice.  I did not see them in carb days. 
Bruce Roe

I notice them too.  I started driving in '76 and recall some car fires back then, but don't know what it was that was burning.

Seems like a lot of burned spots on the highway these days...

[TJ Hopland]

Burnt spots on the side of the road isn't something I have ever noticed in my area.

So really it seems that its nothing special just that it was pretty early for EFI.  Maybe minor material and design issues but likely a lot of people just didn't know how to work on them and what special things needed to be looked out for as they aged.

[Phil Weber]

Here is a link to some GM bulletins referring to the fuel leaks and the remedies GM took to rectify them.

https://books.google.com.au/books?id=FSJJAQAAIAAJ&pg=PA396&lpg=PA396&dq=cadillac+bulletin+78-c-2a/2b&source=bl&ots=ENgWJcnD0r&sig=ACfU3U3e5O6nmPUgRB2SVwYQDzJL7Hm2WA&hl=en&sa=X&ved=2ahUKEwjk7N2RqYXoAhXE4HMBHZs5DWoQ6AEwCnoECAsQAQ#v=onepage&q=cadillac%20bulletin%2078-c-2a%2F2b&f=false