My Official OM617 Toyota Pickup Repower Thread

[OM617YOTA]

Latest little thing, my vacuum shutoff is completely non-functional. I applied vacuum from my brake booster pump to the engine shutoff and she kept running.

[JB3]

Originally Posted by OM617YOTA

Latest little thing, my vacuum shutoff is completely non-functional. I applied vacuum from my brake booster pump to the engine shutoff and she kept running.

how do you have it plumbed? are you using the overboost relay?

Im wondering if the vac pump losing 12 volts means the vac in the system drops before it has time to kill the motor, whereas the stock pump being mechanically driven is still producing vacuum up until the motor kills itself. Im wondering if you can solve this problem by connecting the line to a vac reservoir with a check valve, so that when the relay loses power, it instead of routing to the pump, routes to the vacuum laden reservoir which might suck it closed.

my problem is simpler and stupider.
the vac shutoff system works perfectly routed through the overboost relay connected to the stock pump, my issue is applying a reliable form of 12V that the key actually shuts off. Removing the engine computer has created an incredible amount of weird issues on key on wire voltage. Im having to run a signal wire from the radio power out to the engine to throw a relay, to run the overboost valve.

[Walkenvol]

Some folks have run a tube from the cut off valve on the IP inside the cab and suck on the end of the tube to shut down the OM617 while others use a syringe to create the needed suction so the amount of vaccum required is not much. Sounds like the diaphram is compromised in yours but you could use either of the above methods to trouble shoot or use your mighty vac if you have one.

[Simpler=Better]

Originally Posted by OM617YOTA

Latest little thing, my vacuum shutoff is completely non-functional. I applied vacuum from my brake booster pump to the engine shutoff and she kept running.

Does the syringe test method work?

Sounds like it might be time to buy a choke cable and get creative

[OM617YOTA]

Tried the vacuum shutoff with engine running and just hooked the vacuum pump up to the shutoff port manually. Also tried the syringe- no effect. Got the choke cable already, that's the next step.

Thanks all!

[Simpler=Better]

Originally Posted by OM617YOTA

Tried the vacuum shutoff with engine running and just hooked the vacuum pump up to the shutoff port manually. Also tried the syringe- no effect. Got the choke cable already, that's the next step.

Thanks all!

Since yours is shot already, I've always wondered if the stock vac unit could be hacked up and a choke cable made to pull it, instead of relying on the linkage shutoff setup.

Feeling adventurous?

[JB3]

Originally Posted by OM617YOTA

Tried the vacuum shutoff with engine running and just hooked the vacuum pump up to the shutoff port manually. Also tried the syringe- no effect. Got the choke cable already, that's the next step.

Thanks all!

I think the cable is an interesting solution, but personally, at least for my own swap, ive been trying to avoid large numbers of secondary actions that are required to drive the conversion around. What about just keeping the vac system you've already designed, and replacing the vac shutoff valve with another OEM mercedes so that it works with your new pump? In other words just replace the bad component

My feeling is that its possible to get to a point where you might be reinventing the wheel in a way. I went through a similar process with my power steering, trying to make a perfectly straight adapter plate so the MB motor would run the GM pump, and finally just went with the OEM pump and eliminated a huge amount of custom stuff, for the same end result

[OM617YOTA]

Yup, agreed on all points. Replace OEM vacuum shutoff is indeed the plan. For now though, with parts I have on hand, choke cable is it.

[OM617YOTA]

Howdy folks.

Drove the truck to work today, was met with hearty approval from my coworkers.

It gets up to 55-60mph just fine, and I had no trouble taking it to 70. I think my concerns about power were mostly because I'd been driving my GTO all weekend and my butt-dyno was miscalibrated.

I weighed the truck at the local grain elevator's scale, 3800lbs or so. Not bad.

The alternator is not keeping up. Drove to work, drove it on break with a coworker to show him how it was going, drove it at lunch, stopped at the parts store after work, drove it home. Went to shuffle vehicles in the driveway at home, wouldn't start. Jumped it, got it moved, put it on the charger, went to full charge. Found a store on Ebay selling medium duty truck alternators for reasonable prices. 120 amps continuous duty coupled with a decent size power inverter sounds good to me, and they're only a little more expensive than the Bosch upgrade replacement. May take some fabbing to get it to fit.

I can do that.

Edit: I busted out the multi meter and took some readings. 12.71 volts with engine running and only the electric lift pump being powered. If I rev the snot out of it, it goes up to 13v. I may not need an upgraded alt, just a stock one that actually works.

[OM617YOTA]

Just had someone offer to buy my truck. I said it's not for sale. They insisted, and I named a price that would get me to change my mind. They didn't like that price, said I would never sell it for that price. I said that's fine, did you miss the part where I said it's not for sale?

Holy cow some people are thick.

[JB3]

Lol, you need to read whunters thread on people making ridiculous offers on his car.

The most I get is people asking WTF is wrong with my van.

[OM617YOTA]

Thanks JB3, that was some funny reading! Some people don't understand that the rules of the game change significantly when the person with the item in question doesn't want to sell it. I'm a sales rep myself and some of the things people do during a sale boggle my mind.

My cobra head intake elbow came in yesterday, got it installed today and took her for a test drive. My butt-dyno(always 100% accurate and repeatable, fine piece of scientific measurement instrumentation that it is, ahem ahem) feels an improvement. Turbo seemed to spool sooner, engine revv'd more freely. Thinking just a decent sized cone filter mounted directly to the turbo is going to be the next step, although ideally I'd like something that sucks in cold air from outside the engine compartment.

Pic 1. Cobra head elbow

2 & 3. Intake mounted. That heater hose was HOT, and I need to re-route that silicone hose for the wastegate.

4. Me touching insulated exhaust after a several mile drive. That's some effective stuff, wish I had one of those nifty laser thermometers.

5. Truck sitting at my girlfriend's house.

[Simpler=Better]

Since it's a non cummins diesel and a modified toyota, and they're both over 20 yrs old the best I can do is $500 take it or leave it man

[OM617YOTA]

$500 will get you a mason jar full of exhaust.

For an extra Benjamin and an extra day lead time, I'll make it biodiesel exhaust.

Got the alternator torn off and the voltage regulator / brushes removed. All looks to be in pretty poor shape. I think if I found a decent used set I'd install it and see, but not going to spend most of the cost of a new alt on this one.

[Beastie]

I started this and then we got hit with a torrential downpour. AS I get ready to reassemble things and set up clearances ( dial gauge ) I see that in some diagrams it shows a washer between the hub retaining nut ( with the cap screw) and the outer bearing. When I pulled mine there was not a washer/ shim.
Should there be one ? I am about to pack and load the bearings so any quick help is appreciated.
Thanks
Alan