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View Full Version : How To Gain Some HP and TQ



89TownAce
08-13-2015, 11:18 AM
Hey guys, first post here. I've had this '89 Town Ace for about 2 months now. Just got it titled in California...don't ask me how. Anyways, I love the van, it's my DD, but it's slow as hell. I also own a '93 Dodge Ram with the Cummins Turbo Diesel and when I opened the hood of my Towny I couldn't help but notice the fuel pump looks just like the one on my Dodge...only a little smaller. I found this video on how to really get the most out of the Cummins pump here https://www.youtube.com/watch?v=sv3fXlmS_YA&list=FLWgcHJFiNsKcFzLclJEUkqA&index=14 and since it's obvious the Towny pump is a clone, I wondered if the same things would work.

Well, I didn't want to get too crazy because I don't want to blow up this motor, but just enough to keep up with traffic would make me happy. I'm happy to report my van is up to par with acceleration now. I only did one thing the same as that video, I turned up the maximum fuel screw ONE TURN. That's it. I didn't touch the fuel pin, smoke screw, star wheel or any of that. I simply backed off the lock nut on the fuel screw and turned in the screw 1 turn. It made a big difference in performance. I no longer have to floor the gas pedal constantly just to keep up with traffic. I feel this is even less stressful on the engine because I don't have to wind it out to 4k rpm anymore. I shift comfortably at 3k rpm now even while merging onto the freeway.

Anyways, I just wanted to share my discovery. I've had it like this for a few days now and I've noticed no issues. Coolent temp still never gets to halfway and it's 100+ degrees here in SoCal right now. My next mod will be a free flowing exhaust and then that's it for performance stuff. I'm actually very happy with the power level now.

Gunflint
08-19-2015, 09:56 PM
Thanks for the heads up 89 ace. I'd be curious to know if someone had adjusted yours in the past. My van is by no means fast (in fact its pretty slow slogging up steep hills/passes) but on the highway in general I have no problem cruising a steady 65+mph (I don't let her go faster than that, but thats my problem :)) with enough acceleration to gently pass the folks going really slow.

Glad to hear you got it ironed out. I'll keep that in mind!!

Matt

89TownAce
08-20-2015, 12:45 PM
Hey thanks Matt. Yeah I mean my van could keep up with traffic no problem before either, but maybe it's just all the asshole drivers here in California that made me feel slow. Every time I merged on the freeway I had some jerk on my tail and cars would try to pass me. I actually felt it was dangerous to deal with this on a daily basis. So by turning up the fuel it's really just to help with acceleration. You should give it a shot and see how you like it. I wouldn't go back now, the power is addicting. You will get some black smoke at full throttle, but it's actually kind of nice to have a "weapon" to get people off your butt and it works like a charm.

BajaHiAce
08-23-2015, 05:13 PM
Thanks for sharing 89Townace.

I'm from SoCal as well and also recently purchased an '89 van. It's a JDM HiAce / 4x4 Diesel with A/T and 46,000 original miles. It was shipped over from Japan and then put in storage a few hours after I received it because I had to take off for Alaska to work for the summer. I'll be headed back down south in about a 6 weeks and anxious to get-to-know my van. Driving it home from the shipping container lot I did notice a lack of power but it was expected as I had read up on the vans for awhile before the purchase. Anyway, I'm very interested in hearing about your exhaust mod when you get to it. Are you simply planning a cat delete or something different/more?

Mine is currently set up as an 7 passenger van but my build will be focused on a camper rig for surfing and fishing in Baja.

Don't know where you're located in CA but if your close maybe we can connect when I'm back and geek out on our new vans.

I was able to title my van in Alaska since I have residency here. It was pretty simple with the proper paperwork from the importer. And cheap. $115 for the title and 2 year registration. Gotta love Alaska. And like my other Baja rigs, it will also have old school Alaska plates.

89TownAce
08-23-2015, 08:02 PM
Dude yes when you're in SoCal we need to meet up. You don't happen to be a millright do you? My buddy just left for Alaska for work as well. Anyways I just wanted to respond quickly as I'm elbow deep in another project at the moment. PM me and I'll give you my cell #. My name is Mark.

Oh really quick I ordered my custom plates today. They say VAN DSEL. Stupid I know, but if made me laugh.

BajaHiAce
08-26-2015, 12:05 AM
PM sent Mark. Good pic on the plates.

Gunflint
08-27-2015, 10:44 AM
Glad to hear more of these things are getting imported into the states and there are more Townace owners active on this forum!!

Here is a shot of 'Maggie', our camping, climbing and surfing rig:

http://www.toyotavantech.com/forum/attachment.php?attachmentid=2855&stc=1

Matt

89TownAce
08-27-2015, 10:57 AM
So cool. My Towny doesn't have curtains and only has the lower tracks for them. I don't even see how or where an upper track would go? Maybe I can pick your brain on how to add curtains to mine.

Gunflint
08-27-2015, 11:23 AM
The curtains came with the van. They definitely seem to be an aftermarket addition.

Check out this thread:
http://www.toyotavantech.com/forum/showthread.php?2838-Installing-Curtains-Passenger-Van

Mine are essentially what 'rkent' did.

Matt

89TownAce
09-01-2015, 04:30 PM
Hey I just wanted to update this thread for anyone that's thinking of adjusting their max fuel screw. I ended up backing it off 1/4 of a turn. This got rid of the black smoke. Now I only get a very light grey smoke if I floor the accelerator, but power is more than adequate and I rarely need to floor it now.

So 3/4 of a turn is all you need!

89TownAce
10-29-2015, 12:41 PM
UPDATE

As many may have already read I went on a pretty epic road trip recently and my van developed some issues. One was a fuel leak that ended up just being a fitting at the pump inlet. I had the pump completely torn apart only to discover after reassembly that it was just the fitting (lesson learned).

The other issue was a sort of whistling squealing sound, which I believed was the bearing in the turbo going bad. As it turns out my turbo is fine! I bought a new turbo, but I'm going to keep it as a spare. The whistling sound ended up being a warped exhaust manifold. I was getting a LOT of blow by on the #4 cylinder (or is it the #1?). It's the furthest cylinder from the turbo. Anyways, I have the manifold with me today and we're setting it up on one of our horizontal boring mills to see how bad it's warped. Upon visual inspection it only appears to be warped perhaps .010" or so...very minimal, which is good. We will take a minimum cut on the manifold to make it perfectly flat again and then everything is getting put back together.

This leads me to believe that my exhaust temps were simply too high on my long road trip in the hilly bay area. With that in mind I'm going to further dial back my maximum fuel screw on the pump. I'm basically going to turn it back until I get zero smoke at full throttle. If that means I have to go completely back to stock then that is what I will do. I'm at 3/4 of a turn now and I'm expecting I'll need to turn it at least a half a turn to get to a safe level of fuel/boost. That will leave me at only 1/4 of a turn above stock, which probably equates to maybe 5 hp. On this engine every little bit helps though.

My primary concern now is reliability. I have new gaskets on all exhaust components and also new valve cover gaskets. I no longer have any oil or fuel leaks. This Towny will be my daily driver for at least another year. After that time I anticipate having a lot of custom work completed. I'll decide after that if I want to keep it or sell it. The only reason I am even considering selling it is I've got a love affair with the 2017 Ford F-150 Raptor. Yes, it costs a fortune, but I've got a few vehicles I would sell to buy it...possibly including my Space Toaster.

Gunflint
10-29-2015, 03:13 PM
Thanks for the update!

I also have a sound that I am beginning to expect may be the exhaust manifold gasket. It is the most apparent as the engine is warming up. It sort of sounds like a hybrid belt squeal, whistle and bird chirp type of noise (if that makes any sense....hard to describe a sound I guess....) Once the engine is warm is seems to mellow out a bit. Did you remove the manifold yourself? If so would love to get a run down on the process.

Could you post a photo of the max fuel screw. I am assuming it is the allen wrench looking thing on the top of the injection pump? Also if you could articulate which direction you are turning it to do what that would be great. I get some smoke on heavy loading (up hills) and am curious if I turned it down a quarter turn it would mitigate that.


Thanks
Matt

89TownAce
10-29-2015, 03:37 PM
Thanks for the update!

I also have a sound that I am beginning to expect may be the exhaust manifold gasket. It is the most apparent as the engine is warming up. It sort of sounds like a hybrid belt squeal, whistle and bird chirp type of noise (if that makes any sense....hard to describe a sound I guess....) Once the engine is warm is seems to mellow out a bit. Did you remove the manifold yourself? If so would love to get a run down on the process.

Could you post a photo of the max fuel screw. I am assuming it is the allen wrench looking thing on the top of the injection pump? Also if you could articulate which direction you are turning it to do what that would be great. I get some smoke on heavy loading (up hills) and am curious if I turned it down a quarter turn it would mitigate that.


Thanks
Matt

Matt, the max fuel screw is located on the backside of the fuel pump (facing the rear of the van). The picture I have attached is NOT the exact same pump as ours, but is close enough to give you the location of the screw. The screw has a tamper proof collar on it from the factory that must be removed to back off the (14mm ?) nut. Once the nut is backed off, the central screw can be turned INWARD (clockwise) using a flat head screw driver. Like I mentioned before I don't recommend turning it more than 1/4 of a screw unless you've got a proper aftermarket pyrometer on your cylinder head. It's entirely likely there is a safe level above this setting, but I'm no longer willing to risk warping my head.

The screw on TOP of the fuel pump (the allen wrench one) you're referring to is called the "smoke screw". This screw adjusts the pre-load on the fuel diaphragm. If you screw in inward (clockwise) you will make the diaphragm stiffer, which means your engine will get less fuel at partial throttle. If you screw it outward (counterclockwise) you will make the diaphragm more sensitive, which means you'll get more fuel at partial throttle. More fuel = black smoke.

Adjusting either the max fuel screw OR the smoke screw can cause you to run rich. If you're van emits black smoke and you are certain your pump is at the OEM settings, then the issue is most likely with your turbo or you have a good exhaust leak (like me). In my case, the exhaust manifold was warped, which allowed exhaust to escape BEFORE getting to the turbo, which meant the turbo was not getting proper back pressure...so I was smoking heavily as the air/fuel mixture was too rich. Combined with my max fuel screw adjustment I was just going through too much fuel and not enough air.

If you have no exhaust leaks and still are getting black smoke then it's very possible someone has messed with your fuel pump in the past. To determine what screws were increased you have to see when it smokes. If it smokes a lot under partial throttle it's most likely someone simply turned back the smoke screw. If it only smokes when you're over half throttle and gets progressively heavier as you get closer to flooring it then someone has turned up your max fuel screw. If it smokes at pretty much all levels of throttle then it's possible someone has really "gone for the gusto" and turned both screws up (and likely turned up something else inside the pump called the star wheel). There is even a further adjustment that will also increase smoke output. It's called rotating your fuel pin. It's a quick and easy way to get power, but again, these engines obviously can't handle the heat.

My Dodge Cummins truck has nearly the same pump and I can crank that sucker up as hard as I want and it can take it, but my transmission becomes the weak spot. These Toyota diesels, unfortunatly just aren't heavy duty enough to withstand the heat.

My current suggestion for getting the most, reliable power out of the 2C-T is just a 1/4 turn of only the max fuel screw inward, a 2-1/2" turbo-back exhaust system and just basic things like a clean air filter, clean oil, clean fuel filter and most importantly for our vans is to keep weight and wind resistance to a minimum. As much as I want a kick-ass roof rack or brush guard I will likely skip those additions as acceleration and mpg's are more important to me.

Gunflint
10-31-2015, 04:07 PM
Thanks 89ace!

I'll poke around with that thing when I get a minute. For now the van is running great, so I am hesitant to tweak stuff too much

Im curious about this:

"If you're van emits black smoke and you are certain your pump is at the OEM settings, then the issue is most likely with your turbo or you have a good exhaust leak (like me)."

I've heard black smoke is generally related to excess, unburnt fuel in a diesel. Blue smoke is burning oil, potentially from the turbo. I follow your logic with the exhaust leak causing with the turbo not getting proper back pressure with an exhaust leak causing the black smoke, but I guess I don't understand how the problem could be the turbo itself. If the turbo was going I would think the smoke would be blue not black? Food for thought.

I was also thinking the black smoke could be clogged injectors, irregular spray causing inefficient fuel combustion? Who knows :)

Anyway I am so stoked to see the diesel forums alive!!

Matt

89TownAce
10-31-2015, 05:16 PM
If the turbo is going bad usually that means the bearing is going bad and the turbo can't spool up easily so it will start restricting airflow...or at least giving you less than ideal boost. Either of those situations can cause you to run rich.

Yeah blue smoke is usually oil which would probably have nothing to do with the turbo unless somehow the oil is getting past the seal's to the compressor.

Gunflint
10-31-2015, 06:44 PM
Ah. Thanks for the clarification!

TheCrippler
10-31-2017, 07:21 PM
I know this thread is kinda old but i was reading through about the experience with turning up the fuel. I'm definitely no expert but from what I've been reading lately it sounds like turning up the fuel will cause excessive heat if not matched with additional air intake.

My theory is that the exhaust manifold started to warp from the excessive heat which gave false symptoms of a bad turbo. BUT that could have been remedied by turning up the pressure on the turbo to match the fuel. The smoke described from turning up the fuel definitely seemed like a symptom of not enough air.

I have read in a few places that the increased boost actual brings the temp back down. An intercooler would really solve the problem.

I'm thinking about installing an EGT probe. If you can monitor the temp and get a nice baseline it should be easier to tune the fuel pump/turbo and not damage anything.

Maybe a better diesel mechanic has input?

Intercooler would really be awesome.

oli larsen
11-10-2017, 06:08 AM
hi all, I guess this is my first response/post on here!!
im hawking from all the way over in Sweden.
the van has been in England with me for the past six months while I tweaked and worked on it. now its exploring the far reaches of Scandinavia.
so oddly used to be a turbo charger engineer so this topic caught my attention.
simply winding the fuel up is not a clever idea. it will give you a instant hit of power but is terribly inefficient and not the best for the engine. you are creating lots of carbon which may look cool but clouds of black smoke is busted wasted money. smoke does not equal power.
the only way to gain decent reliable power is to increase the air to match the heavier fuelling.
so obviously this means more boost and a less restrictive intake.
however more boost means higher charge temperatures especially in a warm climate! higher charge temps plus more fuel means pre ignition and very hight exhaust temperatures.
basically the best solution is to get a charge cooler, or a side or low mount intercooler and this will already increase performance, economy and reliability! as we all know the radiator location is less than ideal and the ac radiators if you have them further inhibit air flow.
the next stage is to increase boost from the stock 8-9 psi to a stable 11-12. anymore than this and you are stressing a very old turbo. remember that as boost increases so do the loads on the thrust faces and bearings in the turbine. its squared so a tiny boost increase will quadruple the load on parts.
just lowering the intake temps and a little more air will give a lot more power and efficiency.
more fuel is not always better!

oli larsen
11-10-2017, 06:12 AM
and one other thing, if you have a smoky exhaust its not necessarily too much fuel. the injection timing is paramount to clean exhaust gasses. white smoke can come from incorrect injection timing and if your turbo is healthy and young its always worth checking your cam belt alignment. it gets mighty complex when you delve into true injector timing. similar with black smoke, if its getting enough air and the injectors are spraying well at the correct pressure then timing maybe out.

TheCrippler
11-10-2017, 09:24 PM
Thanks for the detailed reply. Makes a lot of sense. I'm definitely looking into an intercooler. I'm thinking of removing the rear blower for the ac/heater and putting an air to water cooler there. It's nice and close to the intake pipe after the turbo. Then putting a giant heat exchange below where the ac condenser used to be.

A little extra power and a lot of extra reliability sounds good to me.

Also little known fact that all good turbo engineers drive Toyota vans!:thmbup:

Andywear
05-13-2021, 05:23 PM
hypothetically ...
\ /
if someone where to cut off and steal my CAT, and then for some odd reason my muffler fell off (rust and such, you know these well taken care of yotas:wave1:).... and I found some piping I could clamp on to get the exhaust piping from underneath the van, no carbonmanoxcide poisoning please ( https://www.oreillyauto.com/detail/c/walker/exhaust-parts/exhaust-pipe/a070ea617593/walker-exhaust-pipe/wal0/54398?q=exhaust+pipe&pos=461), what would be the mechanical problems that would develop over an extended period of time?

location I am at, Sucklahoma, has no yearly inspections.


https://www.instagram.com/p/COlEJgABJAQ/

^^ lets hope that link pulls up the right pic.

TheCrippler
05-14-2021, 02:49 PM
hypothetically ...
\ /
if someone where to cut off and steal my CAT, and then for some odd reason my muffler fell off (rust and such, you know these well taken care of yotas:wave1:).... and I found some piping I could clamp on to get the exhaust piping from underneath the van, no carbonmanoxcide poisoning please...


About a month ago I noticed my exhaust was pretty rusted and had a leak around the middle the way down the length of the van. There's a point at which you can just unbolt most of the exhaust after the little flexible joint. Pretty much right where my leak was. I thought that flexible joint thing was a cat at first, but its not.

Long story short, I just unbolted it there and removed the whole thing. It feels like it has a little more power, can't say its a ton but its something. Its actually not that loud because of the turbo and I've been driving around with no exhaust for the last month. Just idling and driving around real easy, its not that loud at all, but you can definitely hear it when I step on the pedal hard. I plan on leaving it this way unless I start noticing fumes. Probably just put a straight pipe on there to move the fumes away farther. Added bonus: you can't hear the kids complaining in the back cause it drowns them right out! Probably works for parents, in-laws, spouses, and significant others too!

In case you're curious, I live in California but the van is smog exempt so no worries there.

Andywear
05-15-2021, 09:25 AM
thats great news!

Thanks for the info.

I tried to watch some youtubers who cut theirs off and was discussing the results but couldn't complete watching a whole video.:wall:
which means Ill have to give it a try.

Andywear
05-27-2021, 05:19 PM
UODATE:



11118


11117

Glad I did it, the muffler was bad and I didn't even know.

not really any louder, I can clearly hear the turbo whistle, which is what I wanted :clap:
Also, weight reduction bro.

I'll be watching the MPG and see if any help there.

Andywear
06-17-2021, 12:44 PM
I'll be watching the MPG and see if any help there.

city and very little highway this tank, 23MPG and that is with me gassing it under bridges and in tunnels :LOL2:

11136


One issue I have noticed is, when in gear, with no throttle, just let off the brake peddle and let it creep, like backing out of the garage, the van shakes. If I give it throttle or put in natural or park the shake disappears. I wonder if the air / fuel mix needs adjusted now that there is less resistance, back pressure from the cat/muffler, I guess?