EPICjurneez

Hmm, what kind of difference did the fuel pump swap make? did youget more power? mpg?
thanks.

Kiely

EGR = Exhaust Gas Recirculation. it's an emissions valve.

It could very well be a leaking EGR. The link to the manuals provided above will provide all the info you need on testing the EGR valve and sensors. It also provides troubleshooting charts to help you isolate the problem.

FYI... You will need a vacuum gauge and multimeter.

muddpigg

iTrader: (1)

If its the egr an easy and cheap test is to make a block off plate, i used a coke can and cut it to fit between the egr and intake. The EGR mates to the intake in the back, maybe some one will post up a pic.

I can of ether can test for vacuum leaks, just spray some at correction sites, engine will rev high if vacuum leak sucks in the spray. Visually inspect them too for signs of dry rot.

Download the factory servive manual, its availible free somewhere here on yt is a link. This is far superior to chilton or haines.

To clean injectors properly they need to be pulled off to clean. Believe I went with witchperformance.com after all if you put a new motor in and have the same crappy fuel pattern spraying in you won't see a big difference.


Every bit of knowlegde you need to do these things is available on here on YT.

Jay351

So, Im curious, why do you have a rebuild motor? Did you blow a headgasket or something?

If so, have you done anything to your exhaust system? Have you checked for a clogged cat (will restrict higher RPMs) or tested the O2 sensor. Both of those guys HATE coolant.

EPICjurneez

Exactly. it was a series of running low on coolant, engine started overheating, filled with coolant+distilledh20, and repeat. this was a slow process for a period of 2 years. then within the last half year i became quicker, fuel economy worsened. i was checking for 'milk chocolate' in the oil cap over the whole period and then within that last 6months, there it was. finally, one day, the engine wouldn't even turn.

I haven't checked for anything assuming the garagers did during install. My rpm's do run high though. it just lags from 2k to 3k rpms then it picks up past 3k and up.

still any suggestions?

tdoug23

well sometimes when i have the a/c on it does that with the idleing, it surges up and down

briholt

New to the forum, but not new to toyotas; did most of my forum chats at Off-road dot com...had an 86 22r 5 years ago and recently got a 91 22re. Not getting good MPG at all-- about 12.5 mpg.

I discovered that my right front caliper was dragging, so I rebuilt it, that seemed to help some, got up to 15 mpg. But now I'm back down to 12.5 If the brake lines are fouled up, making it hard for the calipers to release, how would one clean the brake lines out? Flush it several times? The brakes in the morning are grabby and tight. Once they warm up some they are fine. Makes me thinkg the lines are bad, or maybe even the master cylinder?

As far as the engine goes, I've got new cap, rotor, wires, plugs; I've checked the timing, changed the 02 sensor and I'm still getting crappy mileage. The engine runs really strong. Good acceleration, feels tight, but the exhaust smells rich and there is carbon on the tailpipe. I don't get to drive it far, so it is rare that I get above 3rd gear, and I don't have a lead foot. With my 86 I was consistently getting in the 19-22 mpg range.

I can't run ECU codes easily because the lamp behind the dash isn't working. I've attached a test probe light bulb to some wires and was able to 'hack' into the ECU under the right front kick panel and the code I got over the summer was the knock code. That shouldn't make huge mpg differences though, right? I've also checked the TPS settings and they were in range.

I've only had it for about 1400 miles. It's got about 70k miles on the rebulit, 213K on the truck. I don't know the gearing ratio, though in 3rd gear at 3000Rpm, I'm going exactly 40 mph, with 31 inch tires--driving by radar speed signs indicate that the speedometer is accurate.

the shocks are toast, and I'd like to get new tires that are for highway, some good shocks (not extreme, maybe a bit better than basic--any suggestions?), but really not sure what is keeping the gas mileage so poor.

Any suggestions would be appreciated.

briholt

bumping this, with a recap:

1991 deluxe
70K on rebuilt 22re, about 170k on the truck

Problems:

• 12.5 mpg
• fuel runs rich (as evidence by the carbon buildup on the tailpipe, and a little bit by smell)

What I've done:

• I've attempted to pull codes, but the CEL is burnt out. I had a guy at a local part store run a diagnostic, and the code he got was 13. When I tried it using a probe with a light bulb, I think I was getting the knock sensor. Generally, the engine runs very well and strong and tight. Perhaps too tight. Seems like when I let off the accelerator the truck immediately begins to slow down (sorta like engine compression braking).
• I've replaced the spark plugs (old ones were warn, but no real indication of poor performance)
• changed the plug wires
• changed the cap and rotor
• I've replaced the thermostat (it would never get to idling temp)
• set the timing and idle
• checked the TPS. Using 4Crawler's website, I tested my TPS and got the following. His table is here: 4crawler's tps table (you have to scroll up just a tad to see the correct table.)
  
  Test 1: 1040 ohms
  Test 2: 90 ohms (this seems really low, but still under 2.3k)
  Test 3: Open
  Test 4: 5000
  
• replaced a portion of the header exhaust pipe (the pipe just before the cat converter) that had an exhaust leak
• replaced the o2 sensor
• put a refurb'd front right brake caliper that was dragging lots (was at 13 mpg before swap, got up to about 16 after the swap, but now I'm back down to 13). Currently, the tire rotates about one full turn before coming to a stop, and when it does, it back spins a bit telling me that the calipers aren't sticking. Before the caliper swap, the tire would spin about 1/2 a turn and come to a complete stop.
• Also, my commute is really short, about 6 miles non highway. I'm not a lead foot, either
  

If it weren't for the fact that the tailpipe is carbon coated with a gas smell, I'd only be looking at the brake system. On that front, I'm looking to do a complete bleed in thinking that the lines are gunked up so that the calipers aren't fully releasing--course, when I spin the tire they don't seem to be draggin. ugh.

What I'm planning to do

• Bleed the brake lines
• clean the throttle body
• Check AFM? Although do I have to break the factor seal on its housing? how do I get back together? Can I just use regular silicone?
• get some highway/street tires. Currently I've got some aggressive 31's
• I'm considering pulling the injectors and having them cleaned, though that's not going to be the top priority for now.
• Suspension is pretty shot, too, so eventually will get those done

What am I missing?

Cookiehead


------------------------
update to solve my fuel issue...
------------------------
I'm up to 18 mpg and am going through my posts to update.


Here is what I did:
1) though I wasn't getting any CEL warnings, I checked all computer diagnostic connects (02, tps, anything that conceivably would be related)
2) all codes checked out, I took off my intake plenum to clean it out and to remove the injectors.
3) sent the injectors to RC engineering to have them tested, cleaned and calibrated
4) cleaned the heck out of my plenum. There was about an 1/8 of black gunk through the plenum, including and especially the pipe that carries the exhaust from the EGR valve. that part was completely clogged.
5) cleaned the and tested the egr valve

when I put it all together, I had to shut down the idle screw, which was basically all the way open.


It's only been a week that I've been driving it, but the fuel consumption is about 18 mpg in seattle, minimal highway driving.

bwiygul

hey guys and gals, i know i'm butting in, but i have a question too and couldn't find it so i thought i'd throw it in, if anybody has any suggestions a pm would work so i don't take away from this post. i had crap mileage after a rebuild too so after the normal checking i found my tps bad, so i swapped and adjusted it according to the fsm and here's what i got. with the old and new tps i got 200 miles per tank and about 225/tank respectively.. with the tps UNPLUGGED i get about 280-290/tank!! vacuums are good, no cat, coolant temp sensor is good, plugs wires everything is the same except for the tps plugged in or unplugged...and it's all adjusted right according to the fsm...any ideas?

briholt

wow. Love to hear confirmation on this. You just have the TPS unplugged, with the connector dangling?

flyingbrass

Have you felt your hubs after driving to check if they are unusually hot? I'd think that if your brakes are dragging enough to hurt mileage that much they'd be pretty toasty.

bwiygul

yeah, my idle went up too when i pulled the connector. but i turned it down and it runs fine. it seems like it may, if it does it's pretty minimal, have a bit more power hooked up but overall it seems just fine without it? this is weird to me but that's what it's doin...i get about 18-19mpg unplugged and about 12-13 with it hooked up. any chance anything is getting messed up with it unplugged? by the way i bagged and zip-tied the connector.

briholt

Are we discovering how the TPS isn't really necessary?

briholt

At another website, I saw someone refer to 'limp-mode' by disconnecting the TPS. The guy who did that replaced the TPS and all better. Though it makes me wonder, if I'm getting the proper resistance doing an ohm's test, could the TPS be bad?

I've just disconnected mine, seems to run better, idle went up as others have reported.

rangerruck

though I am no expert, I would say your mileage, at 20 and 26, is good to fine!
I would also agree with some kind of vacuum issue; I would also say do a Seafoam treatment, just to make sure everything is as clean as it can be, from the intake plenum, down to the fuel injectors and tops of the cylinders.
If your car is running basically i agree with the other dude, your afm, and your tps is proly fine, they auto adjust for everything, along with 02 sensor.
Lastly, keep the tires well inflated, i like 5 lbs above the norm, and remember,
Neutral is your friend! i cost whenever possible; coming off a freeway, heading towards a stop light or stop sign, whenever possible!!!
I am getting your mileage right now, with mostly city driving, on an 88' with 250 k on it. I am gonna throw on a bigger pipe and a Borla exhaust, and see what happens with that.

rangerruck

1 more thing; are you , above dude, saying, you can run without a hooked up
tps? I didn't even know this was possible? is it dangerous to the ride?
Will this hurt stuff in the future? Hope someone can answer this...

Chutchman

You were getting 26mpg with 31s? Holy crap. 4x4 right? The best I have ever pulled with that setup was 21mpg! And that was with my single cab.

rangerruck

... hope it isn't anything crusty, in the ecu itself!!!

1tonyota

just for the record yes u can run with out a TPS u just wont run that well. Now pay attention son and im prob much younger than you. i like you faced this prob so before u throw well over $1000 into figuring this out i have taken the liberty of doing so. 1 i want you to disconnect the hose that runs from the charcoal canister to the intake and plug the openings with something. 2 go get a new TPS sensor if u havent done so allready. if u have a new TPS make sure your getting a good connection. 3 there is a valve that sits on the upper plenum of the intake that usually has a plastic screw on it and it operates your idle up assist while steering. remove that and plug all the holes it connects and is connected to.( a bad 1 of these will cause an idle of 1400 or more reguardless of where the idle screw is.) 4 check the IAC valve which is attatched under the lower intake plenum on the front near your water temp sensor this to will cause your problem. make sure its getting a good connection or just go get another one.( a bad one will cause idle surging and will also cause high RPM'S on cold starts.) 5 dissconnect the idle up valve for airconditioning as well which i think is also related to the same valve as mentioned above in #3.) if u disconnect anything be sure to plug all holes so there arent any vacume leaks. here is my trucks set up 1986 toyota 1ton longbed 22re toyota supra w58 transmission with 16 inch mustang rims running 225/75/16 inch tires in the back(quite possible the biggest tire u can fit back there on a 2wd truck) engine is all stock. all stock set up. 4 brand new platinum plugs with 4 prongs brand new distributor new TPS new o2 sensor new wires. a completly cleaned intake absolutely no carbon anywhere. 4new injectors and i also plugged my egr valve. currently running 32MPG on the highway at 70 running about 2700 RPM maybe a bit higher but its def not over 3000. i think your 2 biggest problems u need to focus on is the IAC valve and that other valve mentioned in #3 on the upper plenum. also just make sure all your wires are connected and arent frayed or simply twisted together. let me know if this helps.

briholt

re-posted with paragraphs added.