78 bus stock FI No Power Under Load

[VWGirl]

78 bus stock FI

So my bus sat for a year... I know, worse thing I could do, but it needed a new tank and between school and work and moving and getting married I just didn't have time to fix it.

So, before the bus was parked 9/08 everything was running great... just had fuel leaking everywhere so not safe!

So, 9/09 I replaced the tank, replaced the filters many times thinking I had a clog from rust or something cause it was cutting out... turned out to be an intermittent coil issue. I still have a secondary clear filter installed and it is as clear as can be.

Injectors are original never been cleaned except for running things like seafoam through them after the bus sat ten years before I got it and then after I let it sit a year.

Condensor, fuel pressure regulator and plug wires are 5 years old

cap, rotor and points are new as of september. Timing was set with a dwell meter in sept.

Coil was replaced in Nov... twice

I had not replaced the plugs in 5 years & 30k miles. They are now new (as of today) Bosch Super Plus.

So my bus has been running great still... doesn't skip a beat... but it doesn't like to go up hills anymore. I am lucky if I can go up a hill in 3rd gear now, it is usually second... splitties can pass me! The same splitties that I could pass going up the skyway as recent as 11/09.

I replaced the plugs today. They still don't look bad. They aren't super coated in anything, the edges are still pretty sharp, gap is on point... 3 were a greyish color, one was black. After changing them I drove up the biggest hills I could find in Marietta, which isn't much, but it did fine, it was gaining speed rather than losing it.

I am not sure when exactly you are supposed to change the newer plugs... is it 15k? When I use to change my plugs at 15k they looked really new and i was told I was crazy for changing them so frequently with new plugs... so am i supposed to change them?

Did this likely fix my issue or should I be looking at replacing my original injectors? I have a new set in the box ready to go... I am not really sure how to test them well enough myself to know if they are functioning properly.

I;m going to try to find another nice big hill to drive up and see if my power is restored... how easy are the injectors to replace? do i need to replace anything else when i do it other than the injector seals? I don't really have much time to get this right before I head out to camp friday morning. I also need to rebuild my sticking brake caliper (yay for sitting for a year)

ideas?

[Randy in Maine]

I would check the fuel pressure with and without the vacuum hose attached.

[VWGirl]

will do, what about the temp sensor II?

[bretski]

I would start with the basic tuning routine...valves, dwell, timing. Fuel pressure as Randy suggested. Would also do a compression check. Which of the plugs was black? Did you pull and check them again after you changed them?

I'd check the resistance on the TS II before you think about replacing it...at 68F, resistance should be 2100 - 2900 Ohm.

As far as the injectors go, replacing them is not too difficult. Make sure that you have new seals, and I would take the opportunity to replace the fuel lines as well. I had mine cleaned by Cruzin Performance a couple of years ago (great service, BTW). Use a little spray of Gumout on the hoses to lubricate them before you try to attach them to the injectors (and rails). Makes the job much easier.

[VWGirl]

My fingers are now sore from tugging to get the old injectors off... also had to retire one of the original VW hose clamps and use my last BMW hose clamp. Need to order some more clamps!

Injector process was fairly simple, really didnt even lose that much gas. got back in and she started right back up! she is sounding better already.

I am going to do a compression test this weekend while camping... i don't have the right kit to do it. Tune up has been done, but I am going to check the valves and then redo if necessary... my valves shouldn't need to be adjusted with hydraulic lifters though I thought?

Also just found out that autozone sells GP sorenson new fuel injectors for our buses for $30 a piece... anyone know if these are any good or not? From what I have seen it takes that much to rebuild injectors.

Do you think the 5 miles I drove would be enough to cause discoloration on the plugs already? pulling the plugs in a bus is a pain... is there an easier way to do it? I always end up having to fish out the plug between the cyl head and the tin!

Gonna take her for a drive and then probably skip to rebuilding my calipers... if only i had someone to help me bleed them after :(

[bretski]

You absolutely, positively, need to adjust your valves. Don't believe anyone who tells you that hydraulics are "fire and forget."

Here's the procedure, taken from an older post of mine:

You still need to adjust the hydraulics. Don't be fooled.

Loosen the adjusting nut on the valve you're adjusting. Turn the screw out 1/2 turn at a time, until you get the valve to zero lash (you'll feel an ever-so-slight wiggle). Now pre-load the hydraulic lifter by turning the screw clock-wise 1.5 turns. Move on to the next valve. Lather, rinse, repeat.

You should keep track of any changes in the valves (from that 1.5 turn pre-load) from here on out. This will help you with forensics. If, at the next adjustment, you see less than 1.5 turns to zero lash, that points to lifter wear. More than 1.5 turns suggests valve stretch or seat recession.

As far as the injectors you mentioned, I would not even think about using them. Stick with the OEM Bosch injectors. If your old injectors are gummed-up, send them in for cleaning and service. As I mentioned previously, Cruzin' Perfomance is highly regarded:

http://www.cruzinperformance.com/

You'll need to pull the plugs to do your compression test, so it'll give you a chance to take a look at them. As far as preventing "plug loss" down the tin, there was a recent post about using a piece of breather hose to grab the plug once you have it loosened. Neat trick.

Get the brakes tended to first! Starting is great, but far less important than stopping...


Edit: Here's the thread that mentions the breather hose tip:
http://itinerant-air-cooled.com/viewtopic.php?t=8203

[Gypsie]

Agree with items mentioned above.


Speaking from experience I would say that you should indeed assure the TII is secured and to spec. (definitely secured.) All sorts of issues there, (right Spiffy?....)

Lifters are so easy to adjust that you should keep them in your tune up procedure for trhe reasons Bretski mentions.

I would look into the compression, specially the black plug.

After sitting for a year it needs a good run to get everything back into movin' around mode. Lifters, valves, rings all need some good hot oil coursing through their innards to get em back in the zone.

Where is this secondary filter you speak of? Down stream from the pump?

Without making any changes to it's settings, can you do an AFM test procedure (ala Colin's adjustment method, see his very helpful sticky in Fuel delivery) to get a sense of mix at the different RPM's?
This would be only a reconnaisance mission to see where things are at. No changes at this time.

I suggest you keep on the track you appear to be on with refreshing all the settings and perishable parts to assure that your foundation is sound. Then, if the issue isn't resolved after you have assured that the parts and simple settings (timing, advance, valves, fuel pressure, compression) are ship shape, dig deeper (afm elect. testing, afm mix adjustments etc.)

Sounds like it's getting better already.

Keep us posted.

[VWGirl]

Let me clarify... after sitting for a year to the day, it has since taken a trip to SC and back twice... that's 400 miles round trip each time and a trip to FL and back... which is 1000... so it has been driven 1400 miles since it sat... The problems started on the last trip to SC.

The brakes most certainly did work... but i decided to be proactive and replace the rotors and pads... when i pushed the pistons back in, the inner right side didn't want to go... it eventually did go and I put them back on... well... it didn't want to budge after that... i get a horrible squealing brake noise almost always. It won't blow out with compressed air either... so I am looking at getting a rebuilt set now... but I am holding on to these as they are original to the bus... yeah I know it doesn't matter and there is no way to tell, but whatever. They will probably just sit on a shelf.

As for the injectors... I just learned about the autozone ones today. I was interested to see if anyone had used them, I don't know why I have never bought any there... but could they really be that bad? I bought mine from Python... they are also the ones that rebuilt my Bosch fuel pump 5 years ago... it's still pumping strong, so hope the injectors will work the same. The ones that came off my bus I think are definitely original... they have both bosch and VW stamped in the blue plastic plug... which is the same color blue as the connector on the harness.

I'm running out of time to check everything... can't test drive it until i get new calipers at 11 tomorrow... I really think the spark plugs somehow fixed everything.

i think I have to call it a night on the repairs... need to meet my husband and friends for dinner and then need to get my homework done so i can leave town... hopefully in a bus!

Thanks for all the help... will check in again later if I get anything done, otherwise will check back in the morninG!