Finally fixing the hot start problem on a 78 Fuel Injected

[clicknathan]

I've had a ton of trouble with my starter over the past few months.

A mechanic took it apart, and said it was fried. He couldn't get me a new one, so I ordered one from Bus Depot and installed it myself.

Which fixed the problem...sort of. I could now start the vehicle again, when cold.

However, I've got the hot start problem. I've read quite a bit but can't find a definitive, "here's everything you need to do".

Some facts:

1. When I installed the starter, it didn't come with a new bushing. The old one looked to be in very good condition, however, and was possibly a replacement a previous mechanic installed when working with it. I cannot contact this mechanic because such things are impossible in Mexico, where I tend to reside.

2. The top bolt was a bit loose after 1000 miles or so, so I tightened it again. This caused the starter to work much more quickly (when cold) but also had the side effect of causing a squealing noise.

3. If I use a wrench to connect to the two terminals that are screws on the solenoid, the starter spins, key on or off. If I connect the terminal to the other part of the solenoid with the flat connectors, which go to battery/ignition, it doesn't spin, it just "clunks" once or twice.

4. I am coming to realize what a double relay is, and this is the thing in the picture below (image from http://en.allexperts.com/q/Volkswagen-Repair-833/2008/11/78-bus-fuel-injection-1.htm)

Mine is clearly old. The "b" and "a" markings in that photo, on mine, are held into the Double Relay via duct tape.

5. I replaced the ignition switch about a week or two ago.

6. Aside from the starting issue, after I drive for awhile, say 2 hours in the heat or up mountains, she craps out. She'll start to sputter a bit, and when I get to a slow spot, like a stop light, I'll go to push the pedal and everything will just shut down. I wouldn't think this had to do with the starter (once the motor's going, the starter is on vacation until next time you need to start it right?), but once it dies, and is hot, I can't start it again.

SO, TO MY PRIMARY QUESTIONS:

I want to fix this. I'm tired of stalling out / breaking down in heavy traffic and crawling under there to bang on the solenoid and connect the terminals manually. I'm tired of crawling around on the ground just to get it started in general. My approach today, to achieve this, will be:

A. take out the starter and solenoid and test it as per the John Muir book guidelines.

B. Order a new double relay to replace the duct tape setup I've got now. I don't see one on Bus Depot so if anyone knows a good source, that ships to Mexico, I'd appreciate the tip.

C. What about the thing on the right that plugs into the Injector Ballast resistors? What's it called and should I get a new one of those too?

D. Be happy if A works out, and satisfied that my new ignition switch isn't the problem (without knowing for sure it isn't though...maybe the info I've given can help clarify that?)

Anyone have any additional advice on what else I might dig through? I'm probably forgetting something here, so the more input the better. I have no problem crawling under her to fix and test and replace things as needed, from the comfort of the grassy patch she's parked on now, I just don't want to do it on the freeway / rush hour traffic anymore.

Thanks in advance!

[sjbartnik]

Do NOT attempt to test the starter when removed from the vehicle! The bushing in the bellhousing supports the starter shaft when the solenoid engages and moves the gear into contact with the flywheel.

If you engage the solenoid with the starter removed from the bellhousing, there is nothing to support the starter shaft which can destroy the internal electric motor components of the starter.

Also, the double relay has not a damn thing to do with a sticky solenoid or non-functioning starter.

You should probably perform a voltage drop test at terminal 50 on the starter when cranking and see what voltage you're getting there relative to battery voltage.

You may wish to consider adding a hot start relay so that the current to activate the solenoid is not routed from battery -> ignition switch -> back to solenoid. The relay shunts that current direct from battery to solenoid which using the ignition switch to activate the relay.
_________________
1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[airkooledchris]

Has the TSII been tested to confirm it's happy?

If it starts fine when cold but fails when warm, perhaps it's flooding it with gas thinking it's cold still due to a faulty TSII sensor and a rather rich setup at the AFM.

[busdaddy]

[telford dorr]

X2 above - double relay is not related to a starter issue.

If the starter solenoid 'clicks' when you apply power to the solenoid connection, but the starter doesn't turn, then the issue is probably inside the starter itself, not outside.

- the solenoid must be able to force the drive gear into mesh with the flywheel. This means the mechanism must be clean, properly lubricated, and otherwise free to move. Disassemble, inspect, clean and lube as needed. Don't forget to check the pilot bushing in the bell housing.

- once the drive gear is in mesh with the flywheel, a heavy duty set of contacts inside the solenoid must make contact to supply power to the starter motor. This will result in 12 volts appearing on the solenoid lug which the starter motor wire is connected to. Measure this voltage. If is isn't there (or is low in value), replace the solenoid.

- Once power is applied to the motor, it must pass through a pair of heavy duty brushes to the motor armature. These brushes must be greater than a minimum length to make a positive contact with the motor commutator. The brush holders must be clean so the brushes can move easily. The springs which provide brush pressure must be viable. The commutator must be clean and smooth, without shorts and copper crap between the segments. Disassemble the starter motor, inspect and clean everything. Replace the brushes as needed (if you can find replacements). Check everything and reassemble.

A failure anywhere along this chain of events will result in a starter motor which doesn't perform on command. It's a matter of isolating the cause and repairing it.

Due to the dismal quality of "rebuilt" units, if you have a genuine Bosch starter in reasonably good condition, I'd recommend reworking it yourself first, rather than replacing it with poor quality crap.
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[clicknathan]

Thanks for the input everyone. I'll quote each of you and reply below!

[clicknathan]

Regarding the Temperature Sensor II...is it the wire that runs from the coil into the hole behind the distributor that checks the oil?

As in, the green thing near top left going into the hole as shown in this picture?

If so, how does one go about testing it? The John Muir book asks me to take a reading on various pins, but I have no clue where those might be?

Or how VOM at Rx1 translates to my particular OHM meter, which looks like this:

[sjbartnik]

[lil-jinx]

When the top bolt was loose,was the starter also loose,could you move the starter before you tighten the bolt,if yes then it may have damaged the starter.also have you checked the ground strap at the front of the transmission.Battery voltage at the starter should be the same as it is at the battery.12.36 is low.should be 12.6 or more.
When you short across the 2 stud terminals and the starter free wheels then it works ok with the key also points to a damaged/faulty starter.
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A smart man learns from his mistakes,a very smart man learns from other's mistakes.

[telford dorr]

[aeromech]

Try this next time it fails to crank when hot. Slide under and attach one end of a jumper cable to the starter housing and the other to the battery negative. Then see if it cranks.
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[oscarsnapkin]

[clicknathan]

[clicknathan]

[Randy in Maine]

The TSII looks something like the black wire here... with a 13mm head. Clean the electrical connection really well. Mr. 13mm Grear Wrench is your friend.

[sjbartnik]

[TomWesty]

Maybe I missed it, but have you cleaned all connections? Try unbolting your negative cable where it bolts to the body and clean that end up and shine up the body metal that it contacts. It is often overlooked.
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[clicknathan]

[clicknathan]

[clicknathan]