Mtngoat9

Hi folks,
first time poster. Searched the interweb for answer to my issues and this forum had a lot of sharp folks, so I thought I’d join up and ask here.

Vitals:
91 Runner, 3vze, SR5, manual gear mixer, 155k miles on engine

Has burned a quart a week via #6 for about two years. Miss on this cylinder at low R’s. Put hotter sparking bolt in this hole and it still fouls once a month. Oh well. I suspect a crappy valve stem/seal.

Other than this issue has run OK this way for at least that two years. Always idles a bit lumpy of course but smoothed out and pulled OK once you get the R’s up.

In the last three weeks, it had gotten very hard to start when cold and you could smell fuel out the tailpipe when cranking. Then once you got it going, you were OK.

I had some big muffler leaks and exhaust noise from the front, so I took it in and had the exhaust replaced. They told me the cat looked OK, but I had broken two manifold to exhaust bolts and there was a big air leak upstream of the 02 sensor at that junction. They repaired the manifold/headpipe bolts and put in a new gasket, and replaced everything aft of the cat.

I was hoping when I heard this that I had found my rich running problem, I figured fresh air coming in at the joint would dilute the exhaust with excess O2 and drive the sensor lean, hence the ECU reading this and running rich.

No joy. I still get the fuel smell on cold start, but it starts after three turns but now, hard as heck to start warm and I have zero power.

So, starting with the basics, I replaced all the sparking bolts, all wires, cap, rotor. Now once it starts it does run smoother so I know some of that was needed…but the hot start issue and total and complete lack of power is now killing me. I mean I can barely drive straight and level in 4th at 60 and 3300 RPM. My foot is on the floor the entire time, and a tiny rise bogs me down. Three weeks ago I could climb the hill to my house in 3rd with power to spare…now I dog up it in second with it floored, and still right on the edge of bogging down.

I have trouble getting moving in first, with no torque, the minute I put it in gear I’ll kill it as it lacks the torque to even get you moving in first. I have to rev and clutch slip it to 3k to not kill it starting from a stop. Will not idle hot. At all. Simply drops to 100-200 if that and dies.

No backfiring. No temp issues. Still uses about the same amount of oil. Sounds very smooth at RPM…just will not pull and has zero torque, even in the 3k range. It’s not ‘surging’ as I drive, it sounds pretty smooth…and simply will not pull, at all. I am getting about 9 miles a gallon and must drive with my foot literally on the floor in 4th, just to maintain highway speed. From all other indicators, nothing about this engine itself has changed much.

Checked codes and I get a 14, ignition. I’m suspecting it’s getting that from the funky hole 6 which probably misfires. I checked all the wires and I’ll check the resistances this weekend. I do not want to pay big for an igniter just to find out I still have the same problem.

I’m thinking 02 sensor, or cat IS screwed up and plugged, cold start injector is leaking, or my timing is hosed…though with no backfires and no temp issues that seems unlikely. I hear that jumpering two of the diag contacts I can revert the timing to static, then check this with a light, so I’ll try that.

I thought about the fuel filter, but how can it run rich if that’s clogged?

I know these 3vze’s are notorious for this kind of thing. Any help would be appreciated.

93yota93lude

sounds close to what im having trouble with right now but i tried jumping e1 to te1 to get a code and i got 14 and either 24 or 25 i shut if off to grab my camera to record it now no codes no engine light nothing.... check the jump wire get in turn it to on and engine light comes on but stays on now wont even start at all...

Mtngoat9

Picked up a fuel pressure gauge. Read the factory manual for testing fuel pressure, it turns out I need a special banjo fitting assembly to tap into the left hand rail.

You essentially wing up stacking a second banjo fitting on top of the banjo of the feed line with a common center bolt. That's your pressure tap. (I'll be tempted to leave it on and cap it. )

sucks. thought I'd just plug in and read pressure. 91's don't have a Scrhader valve port in the fuel system, though.

so now I turn my attention to the O2 sensor and cold start temp SW. Maybe throttle position sensor could use a peek, and I suppose the timing.

Mtngoat9

Found air leaks in both the intake reverberator pipe and the last fat intake pipe feeding the throttle body. Some PVC pipe, Shoo goo, and gorilla tape later...it idles like a champ now. The duct and reverberator box bill was going to come to about 300 bucks for three pieces of plastic. I can live with the reverb fix the way I did it, should be fine, but at some point I will pony up for the last duct. Shoo goo should work but it will probably fail somewhere else after a while. I'll post up some pics later.

Got an awesome pressure test kit at Harbor Freight. Two days of interweb prowling really paid off. They have a sale right now and for sixty bucks you get the deluxe professional fuel pressure test kit. Bleed valves, banjo fittings, T's, schrader valves of multiple sizes, three or four custom pipes for domestic stuff. If it's been built, this kit will probably check it out. This is a super, super deal.

So I ran it following the factory procedure..and I'm running 4-5 lbs over pressure at all ranges, idle and 2500 R's. Also too high with vacuum line removed. So it's fuel regulator time, which is easily accessible. Too much to hope for that this will fix it, but it has to be done. Seems consistent with running too rich!

Also tweaked the timing a degree or two, and adjusted the idle speed. Idles real nice now for having a sorta dead hole.

Mtngoat9

Pulled the cat and went for a drive, it revs better and pulls harder. The cat is not obviously damaged (screens all in place) and nothing looks screwed up, but when you look through it all you can see is a tiny circle of light just like this...that guy never got an answer on wether this was normal.

93yota93lude

i took my cat out i just have a straight pipe so i know thats not the problem with my truck right now...

Mtngoat9

Ordered fuel pressure regulator from Rock Auto for 75 bucks. They had a closeout on shocks so I ordered two, ($12 apiece no big risk, if they last a year I win).

Have been totally underwhelmed since placing the cat back in the system now that I know what it drove like without.

I considered some delicate internal repair work with a length of t post (fence type) or appropriately sized pipe for shredding and busting, but since it doesn't look damaged per se and I may someday need it, decided not to simply modify the internals and reinstall the shell.


LC Engineering has a very reasonably priced stainless steel pipe at $75 bucks in the longer one I need (17" vs 12"). I've got one coming.
Stainless test pipe

Mtngoat9

Well, got the regulator on, test pipe on, advanced the timing to 12, open loop. Runs much smoother, idles now since I fixed the intake leaks I found. Broke down and ordered the stupid solid gold ignitor from Rock Auto. Got it today, just installed it. Doesn't look like solid gold to me, but it ought to be at $220 bucks for a 4 oz hunk of metal with some FETS or something potted into it. (*&#*@

Too late to try and start it (wife is asleep). If this doesn't do it, it's timing belt time which is about all I can think of to do, and that's a pain in the arse. At this point I start to wonder.....Oregon engines long block, from down the road, or a 3rd gen with a 3.4? More money and I hate the spare under the rig deal, and i think I'd lose my huge sunroof, which I love. I also do not want to go backwards in stock ground clearance, but I haven't looked into that yet.

I think just putting in another danged 3zve is the way I may wind up going. Never having done a motor R&R in a car newer than a '74, I'm not all that intimidated I just wonder how long it would take. I suppose so long as I have my list of extras on hand, perhaps not too bad. New clutch, knock sensor, injector o rings, gaskets for manifolds...is there a long block 'kit' for that kind of stuff?

Can I do it in two or three solid days?

Mtngoat9

bad, bad words. installed the ignitor last night and now it won't start at all. spark looks strong, jumpered fuel pump at diag connector, I hear it running. smell fuel at exhaust while cranking. this is really, really starting to **** me off.

Mtngoat9

Changed out new ignitor for old one, it started. put new ignitor back in. it started. pulled EFI fuse for 30 seconds, put it back in, it started. tonight when I get home I check codes again. If I get a 14 I am going to scream.

made it work, runs about the same. 245 bucks down the drain. I am my wits end and at the point where i hate this car.

can TPS problems cause something like this?

Mtngoat9

Unplugged the TPS today to see what happened. Idle sped up immediately, now it runs a leetle high, about 1000rpm. Drove it to work, definitely different. Noticeably better torque, not by much, but some. I wonder what this tells me.