New motor / bad milage

[4Rescue]

So, I put a new 22RE in my truck aboiut 2 months ago. It's a stock 22RE, as in none of the goodies from Enginebuilders (boohoo). I went bone stock for relaibility and milage reasons. Well, after 800miles, I'm now getting about 200mi to a tank or a calculated 11-13mpg. Before the rebuild with a really clapped out 240=K motor I was getting about 230 to a tank or about 16+ mpg. Now, I do have a pretty bad exhaust leak (the flange between the Exh. Manifold and the down pipe broke a dstud off and now there is a noticable gap at the flange there) and I now have diagnosed that I have a bad thermostat (it'll run up to a small bit below the red, then "pop" the temp drops down to almost a little too cold for opperating temp.

SO, anyone have any idea on what could be hapening? Would an exhaust leak cause any issues? Could the T-stat be sticking open (as I belive it's sticking closed untill it get's REAL hot) and causing it to run in cold start mode (does my truck even operate that way??)??

Anyway, sorry for the stupid questions, but I'm a little frustrated. I LOVE the new motor, while it's no Diesel, there's something about the idea of having a brand new motor like the 22RE that will rpobably out last the truck it's in...

Cheers and no worries

Dave

 

[DaveInDenver]

Well, you're not alone. I put in a new engine with some Engnbldr stuff and my engine isn't running like a top. It's not in the ~12 MPG range, though. I'm working through issues and I seem to figure out a little more each time.

First thing is to check your valve lash adjustments. The engine is breaking in and they are probably not set right. I had mine at 0.008 and 0.012 to start and after the initial 15 minute break-in none of them were anything close to that. I've done mine a couple of times since and they are holding better now, but in the first few hundred miles you probably need to check the valves a couple of times. I'm also trying to find the right clearance for my Engnbldr cam, so there's some experimentation going on in my case.

With the valves set, check your compression. It's possible that the rings just haven't completely set yet. Mine is still a little low at about 5,000 miles, so it takes some time it seems for the 22R block to fully seat. Makes sense when you think that the engine wears slowly and it might not break in really fast, either. I've heard of people with new engines saying that their mileage increased over a period of 20,000 miles, but I've never really had a brand new Toyota engine before to compare it again.

Next I've found that several of the sensors that I didn't check or replace are unhappy. My EGR valve was sticking, my ECT sensor is off, the O2 I think might be going (this I think was from my break-in and all that crap that was burning off at first has fouled it). I'm also planning to replace a couple of other senders. Basically here you just need to run through the manual troubleshooting steps and make sure the key sensors are working right. That's the air flow meter, throttle position sensor, engine coolant temp, O2, EGR vacuum switch, aux air valve (this is the EFI equivalent of the choke). There's not really a whole lot on a 22R-E, so it's easy to troubleshoot. But one sensor being off or broken will throw the computer into fail safe mode.

Vacuum lines. Not much else to say, but a vacuum leak is certainly possible. I figured out my EGR system was acting up when I was tracing down all the vacuum lines.

Also when you talk about the thermostat sticking, are you sure? You might have a bubble of air in the cooling system. But it's possible that the t-stat is bad. Did you replace that or reuse the old one? In any case, if you believe the gauge, getting hot spots is bad for the engine and running cold will ruin your mileage. It's hard to stress how important having the engine run at the right temp is for the EFI ECU. If the engine coolant is not at the right temp, the computer could be running rich, thinking that the engine is still warming up, for example.

Something that was hard for me to get over is how much crap came out of the engine after the first start, metal shavings and stuff. It's possible that you have debris stuck in the thermostat is what I'm saying. I did my initial start on pure water in the cooling system and plain Castrol in the crankcase, ran for 15 minutes and drained both. I refilled with regular Castrol and the 50/50 coolant mix. But the cooling water has junk in it just like the oil. So maybe flushing the cooling system would be a good idea? Also check the level of coolant, I replaced all the coolant hoses and one of the hose clamps leaked and mine got low. Just forgot to recheck them, something I'm usually pretty good about when I out on new hoses.

Good luck and keep after it. It's taken me a few months but my engine is running pretty decent. Still a few more things to do, but I can't complain. The problem for me is that I didn't replace everything, I reused most of the outside stuff that was 200,000 miles old. So with the long block running well, I'm finding the stuff that my old engine with the worn rings, cam and valves was masking.

 

[spencyg]

I'd put money on the thermostat being your biggest issue. The ECU has two separate fuel curves in its memory. 1 curve is for cold engine operation and runs much richer. The other curve is for standard operating and runs a more efficient curve. You're just blowing gas out the tailpipe right now...

Spence

 

[4Rescue]

Thanks guy's this is why I come here to the Expo...

Dave, yeah, I was wondering about the O2 sensor, and I do belive it is the T-stat, i had this issue before I put the new engine in from time to time, but I have a brand new raditor that I have burped about 300miles ago tghinking that it could be an air bubble. No bubble, and I still have the problem.

And spence, thanks for confirming what I wasn't sure of about the cold runing mode in the ECU.

I just switched to a new schedgule a tthe Hospital (hooray, no more 7p-7a shifts) and I now have alot more free time to go through this truck and get it all reckinoitered.

Thanks guy's

Cheers

Dave

 

[Grim Reaper]

So, I put a new 22RE in my truck aboiut 2 months ago. It's a stock 22RE, as in none of the goodies from Enginebuilders (boohoo). I went bone stock for relaibility and milage reasons. Well, after 800miles, I'm now getting about 200mi to a tank or a calculated 11-13mpg. Before the rebuild with a really clapped out 240=K motor I was getting about 230 to a tank or about 16+ mpg. Now, I do have a pretty bad exhaust leak (the flange between the Exh. Manifold and the down pipe broke a dstud off and now there is a noticable gap at the flange there) and I now have diagnosed that I have a bad thermostat (it'll run up to a small bit below the red, then "pop" the temp drops down to almost a little too cold for opperating temp.
SO, anyone have any idea on what could be hapening? Would an exhaust leak cause any issues? Could the T-stat be sticking open (as I belive it's sticking closed untill it get's REAL hot) and causing it to run in cold start mode (does my truck even operate that way??)??

Anyway, sorry for the stupid questions, but I'm a little frustrated. I LOVE the new motor, while it's no Diesel, there's something about the idea of having a brand new motor like the 22RE that will rpobably out last the truck it's in...

Cheers and no worries

Dave

That thermostat issue is a KNOWN problem. Go to the dealer and get a thermostat and tell them you got the heat up issue that requires the upgraded thermostat.

The Thermostat may be the majority of your problems. It will run rich for both hot and cold.

You are not running anything like a K&N motor sander are you? K&N's if over oiled will get a film on the Ambient air temp sensor and it will pick up dust over time and insulate the sensor in the AFM. Loose the K&N and clean the black nub hanging down from the top of AFM in inside it.

Run the Vacuum line from the Fuel pressure regulator directly to manifold vacuum. The solenoid probably doesn't work and if you have it plumbed backwards it will not lower the fuel pressure at Idle and run a little rich as a result.


The rest Dave covered.

 

[4Rescue]

That thermostat issue is a KNOWN problem. Go to the dealer and get a thermostat and tell them you got the heat up issue that requires the upgraded thermostat.

The Thermostat may be the majority of your problems. It will run rich for both hot and cold.

You are not running anything like a K&N motor sander are you? K&N's if over oiled will get a film on the Ambient air temp sensor and it will pick up dust over time and insulate the sensor in the AFM. Loose the K&N and clean the black nub hanging down from the top of AFM in inside it.

Run the Vacuum line from the Fuel pressure regulator directly to manifold vacuum. The solenoid probably doesn't work and if you have it plumbed backwards it will not lower the fuel pressure at Idle and run a little rich as a result.


The rest Dave covered.

Nope, no K&N, it's all bone stock.

Thanks for the info, I will be heading to the dealer next week to get the new T-stat. And I think I'll climb under the truck and check out the O2 senson as well.

Cheers and thanks guy's

Dave

 

[4Rescue]

WELL...

Replaced the T-stat awhile ago, and it still isn't completely free of the issue I was having. It doesn't get as hot, but it still heats up above the halfway point then drops back down.

BUT!!!! Worst of all, I fired her up this morning, and she turned over after 1/2 a crank... then... thud just cut out and stopped running. Crummy thing is, I just replaced the Exhaust ggaskets that were leaking and it was running absolutely FLAWLESSLY... Pulled like it never had before, the milage even with this awfull winter gas was approaching 17 around town. I was so damn excited and now she's not running... bummer.

Good news is she's back at B&M where the engine was built (the owner of the shop is the Brother of Ted of Engnbldr fame) getting looked at. Hopefully it'll be something simple, but I have this awfull feeling it may have been the Timing belt. When I crank it, it just wont catch, and it sounds like I'm not getting any spark. so maybe the coil, or maybe a fuel pump. BUT, it also feels / sounds like I don't have any compression by the way it won't catch, and since it just flat shut off, and refused to even rty to turn over, I feel like it's more a of a major mechanical issue than an Electrical thing... maybe??? On a good note, I don't hear an grinding of metal, gnashing of parts so maybe I didn't completely thrash it. I've been really good to it in the 1200 miles I've put on it, so maybe it's just a matter of something not breaking in right and coming apart...

Damn I already miss the truck. I borrowed my Dad's 98 XJ Sport, but while the motor is sure fun, it's just not as comfortable a truck to drive and it's an Auto so that stinks as well. I'll reveal the big cause of all this when I find out for myself. I wish I had more time to dive into it on my own, but it's a brand new engine with a waranty, and with the Shifts and OT I've been puting in at the hospital lately, I'm knackered for time as it is...

Cheers

Dave

 

[DaveInDenver]

If you broke a timing chain, it's pretty easy to figure out. Valve cover off and crank the starter, if the cam's not turning the chain ain't a workin' It's extremely, unheard of, never happens that the crankshaft could break and that's the only other reason why the cam would not turn with the starter. That would probably make some racket, though. A compression test would tell a lot. But if the timing chain let loose, you can easily have crunched valves, that would be not so good. How often have you changed the oil? Last time you adjusted the valves? How about the distributor, is it still intact? There's not much that would just go "Thunk" and make the engine stop running, but still crank.

 

[4Rescue]

Distrib. is still intact. Could have possibly fried the main supply wire to the dist. I've done that to a VW beofore, but it usualy sputters and tries to run becuae the cable isn't completely severed. I changed the oil at 500mi as the shop required for warrenty, adn just took it back 2 days ago to have everything gone over after 1000 miles had passed. Like I said, it fired RIGHT up this morning, no issues and then thud...

 

[4Rescue]

Verdict is in... The Timing chain just broke a link...

Good news is, it's all covered under warranty, and nothing else was damamged, so I'll haver her back on Monday sometime...

Cheers

Dave

 

[Paul R]

Glad that they'll get you taken care of. My buddy's truck was doing the heat up thing and then drop rapidly he replaced the fan clutch and the T-stat, and it ran like a champ after that...

 

[Grim Reaper]

Glad that they'll get you taken care of. My buddy's truck was doing the heat up thing and then drop rapidly he replaced the fan clutch and the T-stat, and it ran like a champ after that...

Its' a design problem. The pressure from the pump holds the thermostat closed so that it doesn't open progressively. It has to almost over heat to create enough force to overcome the pressure and pop open. A Non Toy thermostat doesnt have the bleed holes and its a REALLY bad problem with them.

 

[4Rescue]

Its' a design problem. The pressure from the pump holds the thermostat closed so that it doesn't open progressively. It has to almost over heat to create enough force to overcome the pressure and pop open. A Non Toy thermostat doesnt have the bleed holes and its a REALLY bad problem with them.

Intresting, I'd never heard of that specificaly... Good tech mate.

I MISS MY TRUCK!!!!!!

Cheers

Dave

 

[Photog]

My '88 4Runner has the 3.0 V6. You can watch the engine temp rise on the dash gage, as the engine warms up; and watch it fall, when the T-stat opens the first time. Then it climbs up and equalizes just fine.

I ended up using one of the aftermarket T-stats, and just drilled a hole in the approximate location of the factory hole. This lets the bubbles escape. These holes don't let enough water through, to help or hurt the cooling, just helps the burping. The T-stat must be clocked so the hole is straight up (12:00).

It is possible that it may also relieve some of the hydraulic pressure from the water pump too, letting the T-stat open easier.

 

[DaveInDenver]

There is a design uniqueness with the 22R and the heater core. If you pull in cold air over the heater core the coolant is cooled so much that the thermostat closes. Toyota has a fix for this, thermostat P/N 90916-03070. It's a two stage thermostat, probably would fix your issue. This is the one I use, anyway. Also remember that the dash gauge has a dead zone where the needle does not move. This is true of most 1984+ trucks, there is a designed in region of temp that there is no movement of the needle. It's pretty big, like 15 degrees on either side of 190F. So if the gauge is climbing from your normal position, it's really more like 205F and that's getting pretty hot. Just the same, it will read normal at 175F, too. This can mask a poor running EFI because the sender that tells the ECU the temp is reading the actual coolant temp and you might not pick up on it by looking at the dash gauge.

Roger Brown talks about some of this:
http://www.4crawler.com/4x4/CheapTricks/index.shtml#Thermostat