What FI components are most likely to fail?

[westfalexia]

Hi Sambistas,

I have a '91 vanagon and am planning some long road tripping this summer (6k miles plus). With wife dogs and kid. Van checks out fine (130k miles) by vanagon specialist, but I want to "be prepared" and make sure I have the parts I'm most likely to need. As regards the digitronic fuel injection system, I would like input on what components are most likely to fail.

I have spare O2 sensor and air mass meter, but am wondering what is most likely to go bad in an invonvenient place, so I can have the parts on hand.

If this is already covered in another topic please let me know, I searched but did not see it.

Thanks.

[Merian]

dunno but typically people send the injectors out for cleaning which also gets the rubber hose stubs replaced

FPR and fuel rails are popular to replace

all rubber hoses & brake hoses - so do a search on those

pump & tank

all grounds - nice pics of each one on here; relays

sounds like nearly everything, eh

[Terry Kay]

TPS.

And they are NLA.

Big miles & old age contributes to idividual FI parts to give up the ghost at the most inconvenient time.

Is there anything you can absolutely plan on?

Negative.
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T.K.

[westfalexia]

I was looking at the replacement TPS they sell at van-cafe. Gowesty makes one too. Not too expensive, and a nice little part to have on hand...

Rubber hoses I totally agree with. I have been through them, but will have all double-checked to make sure I didn't miss replacing any (fuel lines especially). I think the injectors are in good shape, the van just sailed through its inspection with very low emissions readings. My guess is that injector performance will degrade over time leading to rich conditions, not fail suddenly. But that is just a guess.

Also just re-sealed the fuel tank. Fuel pump is original. Think I should replace it pre-emptively (along with the filter), or just carry around a spare?

And I know they are not FI components so hopefully I'm not getting too off topic, but what about replacing the water pump and oil pump?

And how about the temp sensor near the thermostat. Does that fail routinely? The temperature guage seems to read accurately as of now. I think the FI system relies on input from it too.

Thanks for the replies.

[Vanagon Nut]

[kamzcab86]

[Merian]

injector performance should not fail suddenly, but the stub hoses might

[jmranger]

Welcome to TheSamba.

I'm a bit puzzled by your question. Why are you more worried about the FI system than the remainder of your 34-years-old van?

A few thoughts - apologies if those are obvious:
- if this van is new in your fleet, the best preparation you can make is to put miles on it before the big start. Get used to how it feels, how it sounds, even how it smells. This would serve as both a shakedown of your recent repairs and a calibration of your brain to what's normal and what's not. My personal experience it that most failures will appear progressively, and can be addressed before they strand you.
- Murphy's law: whatever spare parts you bring, it's something else that'll break. Overloading the van just increases the chances that something will break.
- I'm among those that believe that the quality of many spare parts we can buy today is lower than the original parts. Too many stories of "new" parts going bad after a few 1000s miles. So I'm in favor or preventively replacing parts that are known to wear, but against overdoing it.
- If you don't already have Roadhaus and VRS in your bookmarks, now would be a good time to add them.

Have fun, and safe travels.

[Ahwahnee]

You can carry a crazy number of parts (that's me) or just accept that you are unlikely to correctly guess what will fail.

In any case, possibly best to focus on things that could leave you stranded (such as the fuel pump) vs those that you can soldier on without (e.g. the alternator).

I buy spares of most components when the price is favorable (particularly those items that can be had used such as the ECU and AFM. Having done that I see no advantage in having them on the shelf at home while I travel, hence the collection of onboard items.

Every now and then I add something when I hear multiple reports of sudden inconvenient failures -- one example I recently added was a throttle cable.

[Terry Kay]

Here's a question for you;

How long have you owned the 91, and what have you done to it in preparation for this 6000 mile trip?

Nothing is usual, nothing can be anticipated,
nothing can be expected, other than normal wear items failing.
Bulbs, tires, belts, hoses, wiper blades, etc.

I'd have to say that the digifant hardware other than small electrical control items that can & maybe will fail, is nothing to be concerned about.

Make sure every square inch of the running gear from bumper to bumper is sound, serviced, & tighter than a drum.

You'll be fine.

Just remember, it isn't even close to a late model ride, its got 130k on the clock, and it's 24 years old.

Expect nothing, plan for anything & everything.
_________________
T.K.

[Mellow Yellow 74]

[morymob]

In all 5, 25 yrs,norm refresh of fi sys ( hoses,filters ) all grounds etc has ended up being the very least of problems, one temp 2 plug connection ,fairly recent,that area isn't a worry of mine. Getting a flat & changing on todays hhighways is about tops.i carry norm spares, fuel filter,spare pump & water pump. Their shelf life may be a problem in time. Only other spares r ones not easily found at flaps on 1st trip there or one that is expensive, ecu,full dizzy. Some i carried 4 yrs have put back on shelf as i could limp 4awhile if needed. After awhile, & regulator maint, always before a trip keeps things operating. Forgot, had alt reg contacts stop charging, made it ok on batt. I try to remember jumpers,mainly 4 others u see stalled, my 2cts. As usual no warranty offered at this time.

[morymob]

If u suspect a temp2 sensor & have one just plug spare up, take a tie wrap & tie against rubber hose at a convient spot, u can wrap a rag around & tape it down if u like , move on, replace at your leisure, i even tested mine without the wrap, ran normally, my2cts, as usual no warranty offered at this time.

[Wildthings]

By the time I pulled the WBXer engine out of my '91 to do a Suby swap at around 240K miles, I had replaced the idle control valve once and been through a couple of O2 sensors. Never been into the AFM, never replaced the injectors or removed them for cleaning. It even had the original distributor cap and rotor still. Even my POS 83 1/2 has taken very little to keep the FI working fine.

[kamzcab86]

[westfalexia]

Wow, thank you for all the input so far! I am making a list and will post a summary of the parts that have been suggested.

In response to a couple people who wondered why I was asking about the FI system specifically - I have been over the rest of the van in some detail (suspension, brakes, cooling system - yes I replaced the long pipes - resealed the fuel tank, rebuilt the A/T with new cooler and seals), but when I stand there looking at the van the digifiant system seems to have an awful lot of components that are now twenty-odd years old.

In general I believe in the "ain't broke/don't fix" approach, and also feel like good original parts may be in many cases less apt to fail than a brand new aftermarket one. After all they have years of proven reliability. But I do like to be prepared, as much as possible. And I figure in the event of a breakdown, parts may not be so easy to come by for a '91 vanagon.

I've had the van a while and have a good knowledge of its history, but this will be the first time I trust it to take myself and family for a long trip.

and RE: jmranger - I am a firm believer in murphy's law - but also that there is a perverse rule of automotive misfortune, by which if you have a spare part handy, it will increase the odds that the original part will not fail.

Re: wildthings - on the idle control valve. I was thinking about that. If I understand the digifiant correctly the idle control valve and idle control computer (along with correctly functioning and adjusted TPS) are all necessary for the van to idle. Is the idle control valve the most likely part to fail? And if it does, is the van still driveable? It is an automatic so I can't do the 3-pedal-softshoe like I could with my old saab.

Thanks again for the input. And humoring me with this.

[Wildthings]

Yes, if the idle control valve goes bad it will only effect the idle.

[0to60in6min]

check all coolant hoses... small and big...

you may want to replace some that are not easy to do on the road (near the oil filter) ...

if everything went right but you have a coolant leak.. err... you go nowhere...

[djkeev]

Engine idle control.........

Apparently designed by some engineer who had his head deep into some place where the Sun doesn't shine.......
Decided to put the control bits in a similar location!

Behind the Right Tail Light!

Clean it up, dry it out, the relay connections ARE dirty wet and corroded!

Dave
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[morymob]