It Lives!

I got injectors and a resistor pack from Troy (Thanks man!). I got `em in over the past couple nights (did you know 1/4" FI hose will fit if it`s heated up a bit?)

No difference. :(

This morning I hit the junkyard and there was a bug. All that was useful off it, unless a beat to crap case and swiss cheese pan are useful, was the distributor. I grabbed and for giggles tossed it the Guac. Holy smokes it worked!!!

My tach doesn`t peg and bounce anymore, the bus runs great, etc etc.

Something in the two distributors I have must be shorting out, or the ground strap while passing eyeball inspection has a weak spot. I`ll spend some more time checking those out later. Right now... ROAD TRIP!

Injectors and Resistors

I picked up some used injectors and resistor pack from another bus owner yesterday. On the way home I stopped by Target and picked up a box of snack size ziploc bags ($2) and a bottle of medical grade mineral oil ($1.52). I put each injector in a bag and filled it with the mineral oil, then put all the bags back in the Target bag.

They sat that way all day.

When I got home last evening, I installed the resistor pack and one injector, replacing one that I thought was suspect. I didn`t have time to do the rest, so I did a quick test drive. No joy. :( The replacement injector seems to be working nicely however.

I`ll update more tomorrow assuming I get to finish replacing the injectors tonight.

Troubleshooting Update

I finally got to do an AFM swap. No change. Same with the ECU.

The resistor pack tests perfect when cold. Run the engine for a little while and instead of 5-7 ohms of resistance per resistor, I get 3.4-ish on 3 of the 4 resistors. ARRRGGHH!!

I swapped resistor packs with Sykboy and the guac ran MUCH better. Still not perfect, but better. Although his resistor pack tested similarly.

It seems that the resistors were damaged by overvoltage for a long time.

I`ll be getting a new resistor pack and set of injectors. Here`s to hoping!

Fuel Injection Wiring Harness

Photos of the fuel injection harness. I labeled the small connectors to make it easier for me (and anybody else) to reattach it.

The connectors are color coded.
Black: AFM, AAR
Blue: Fuel Injectors
Brown: TS1
White: Dual Relay, Resistor Pack

Note that the spade connectors are not color coded. So label them when you pull them.

Still Need Help

The Guac has been down since January, but I have little time to troubleshoot. So in troubleshooting time, I`ve spent maybe a week on it.

I`ve isolated things (I think).

Symptoms:
Idles from cold start at least 30 minutes (I figure any longer was pointless)
If revved to 2k rpm and held, will only last 45 seconds or so.
- When it cuts out the tach drops to zero
- There are no warning signs leading up to this
- I can repeat this over and over. So it`s not (or no longer) intermittent

Wiring has been checked and re-checked and re-re-checked. Coil
replaced. I`ve now swapped out 3 different coils and get the same
results. Points and condensor replaced. Distributor replaced. I even
put a compufire on it. Exact same results. Wire wiggling does nothing.

Vacuum leaks have all been sealed. The last one was yesterday, a fuel
injector seal wasn`t seated properly which was probably from previous
troubleshooting. (Yes, I got the rear drum loose. The hammer blows did
it.)

Several dual relays tried. Injectors spray nicely when triggered,
don`t leak when off.

Fuel pressure stays up. When idling and warm the vac is between 14 and
15, which is probably good for Colorado.

The only things I haven`t tried are replacing are the engine (heh),
the resistor pack, and the computer.

I`m leaning toward either computer or ignition due to the way the tach
just flatlines like that. Though I can`t see how the computer would
affect the ignition?

Any thoughts? Things I haven`t tried? Help?

Bucking Under Load

The Guac`s been out of commission for a month while I try to figure out why it`s bucking under load.

Fuel pressure is higher than it should, but it probably doesn`t cause this.

All ignition components tested or replaced.

Valve adjustment complete.

Vacuum gauge steady low.

Photos of fuel pressure test here.

Here`s a video of all the gauges going. Note the jittery timing mark is due to the frames of the camera not lining up with the strobing of the timing light. It`s rock solid.