BluVudu

when I took the vac line off of the EGR, there wasn't much vac coming from the line... I don't remember how much I should feel there.

abecedarian

What was the code that told you the O2 sensor was bad?
There's really not a code that says the O2 is bad, just a rich and a lean code.

BluVudu

I don't have the codes in front of me but there was 21...22...31...41...and 51. One was low coolant...which was correct lol. 2 others were nothing. If you have the code list for the truck, which I have in my Haynes book... the TPS and O2 were both there. Not arguing, just saying what I had to go by.

raydouble

FSM links
http://www.ncttora.com/fsm/1993/engine/26diagnosi.pdf
page 5 Diagnostic Trouble codes. ECM testing also

ECT Sensor test
http://www.ncttora.com/fsm/1993/engine/40engineco.pdf

BluVudu

Thanks for the links Raydouble. I will recheck some things now lol

Kiroshu

theres not much vac going to the egr i'd say leave it off though it does not hurt anything in fact should make it run better. Um the codes you threw...51 is alos dealing with your tps. when you installed the new tps did you reset the computer? on these older vehciles generally when the problem is fixed the code will go away.... you must either have your tps out of adjustment bad or not reset it. Um where did you buy the tps.... you really should have bought that from toyota... it comes pre adjusted from them read to slap on... 31 and 41 your coolant temp sensor and mass air flow. I gurantee you the trouble starting problem is coming from the coolant temp sensor i'd trace it down and see if the righ wire is connected to it. The coolant temp sensor is bellow the throttle plate. You will acctaully see to connecters one of them being the cold start time switch i believe its called which is on the left and on the right coolant temp sesnor. be sure those wires are not crossed try and switch the 2 wires and see how it starts. also for your mass airflow. did you buy the one specific for the truck? if so from where did you buy it? if it came from a junk yard or something i'm thats your prob you might have just gotten hold of a bad mass air flow meter. if ya got i from a parts store try getting another one and see if it works. is there any leaks in the main intake tube that too will cause rough idle and airlfow code. you o2 sensor is nothin to look at, at this point its deeper. i how its not ur ECM but try those 2 things.

BluVudu

Ok I will try that... I was just about to go back out there. The MAF sensor was bought at AutoZone but it is a reman Nippon just like what was on it. Someone emailed me and told me to open it up and turn it one click forward inside. I may try that but only at a last chance effort as I really don't want to open it. I did find out that when I was using the jump wire to get the codes that the engine should be at running temp but not running and just the key on. If this is true, that may be another reason why I got codes that I shouldn't have gotten. The codes that I put on here were just from memory as they were written in the haynes book out in my truck lol so I may have just put in the 51 as a bad memory mistake. I will go out and try the 2 things you said and report back.

BluVudu

oh and I didn't replace the TPS because when I tested it, it was nearly perfect. Only a very small amount over the top reading for fully closed throttle. I don't think it would be the problem. I forget the exact number it read but say that it was supposed to read between 500 and 800... it read like 811 V

BluVudu

oh... another question from the newb lol when I reset the ECM... do I need to disconnect the battery for 30 minutes or unplug the ECM fuse? And if I need to unplug the fuse, is it the one by the drivers side kick panel bottom row center that says ENGINE? I am unsure of where the ECM fuse is at unless that's it.

BluVudu

Ok Kiroshu... I'm trying not to get too excited but here's what happened. The plugs were able to be reversed but didn't really need to do it because one is all black and one is all green. So I took the one on the right off, the green one and nothing changed but the check engine light came on. I left it unplugged, reset the ECM and it runs like a scalded dog with the plug unplugged. The only issue that I had was the timing... when I set it to 5 degrees as it says to, it barely runs. When I advance it to about 9 or so degrees btdc, it runs awesome! So I advanced it, left the green plug on the right unplugged and drove it around town. It ran perfect, no miss, no backfire, no flames out the pipe. Now, you said that the plug on the right was the water temp sensor but the water temp still showed on my gauge in the truck. Have I found my problem do you think? Let me know when you get a chance. Oh and I'm going to go out while it's still warm and check the codes again and see what pops up.

BluVudu

Ok... codes... 21,22,24,31,41,42,51. Now that it has been turned off for about 10 minutes, it started right up but when I hit the gas, it hesitates and stumbles like a carburated engine with a bad flat spot. I'm so confused by this thing.

BluVudu

just noticed something new... when I hold the throttle open to where the engine stumbles, I hear a pop from the air flow meter that sounds like the flap in there is slamming open or closed... not sure if that's normal or not. Also, if you get this before I get back in, hold on the codes... I have a sheet here from Toyota and I was doing something all wrong... I wasn't clearing the ECM as I thought I had been so I need to go do that and then see what happens. Thanks for the patience lol

BluVudu

ok... 21*22*24*31*41*42*51 are the codes. Still doing the same thing with the hesitation and stumbling.

abecedarian

check your grounds to the block, battery, head, by the alternator, etc.

BluVudu

yeah I have a friend who has a printout of all of the grounds and I'm going to check those asap.

on the codes...
21=open short in main heater of o2 sensor... I checked the voltage to the o2 sensor and it checks out fine.

22=engine coolant temp sensor... when plugged in, it runs bad... when unplugged truck runs near perfect. When I get on the gas easy, it increases rpm perfect, but if I stomp the gas, it hesitates and stutters and the air flow meter pops.

24=air intake sensor... when I unplug this, there is no change.

31=air flow meter... when I unplug this, the truck shuts down... when plugged in, the inner flap pops when the engine hesitates on hard throttle.

41=TPS... the TPS checks out nearly perfect, just a bit high on the throttle fully closed voltage.

42=doesn't matter right now
51=doesn't matter right now

I let the engine cool for 2 hours and went out and it started right up with the coolant temp sens unplugged. Now for the hesitation and stumble... the closer I get the timing to the correct setting, the less power it has, and by less, I mean bad less... and the exhaust gets REAL loud. When I advance it to about 1 degree, it calls for 5, it runs good, sounds good, has power. Still has the stumble when you hit the gas hard. As a side note to this, the dashpot looks like crap, the rubber boot on it is cracked and I'm not sure if that would cause my problem with the stumble or not. I really REALLY appreciate all of the help with this.

What do you think?

CyMoN

check the intake hose between the MAF and TPS and make sure there is no cracks and it is air tight.

Kiroshu

ok i dunno how it manages to run with the coolant temp sensor uplugged. This seems to me like the computer is getting a fautly temp reading. The computer must thing its hot when its cold and cold when its hot. i'd get a new coolant temp sensor, or try taking it out and cleaning it. you said its not the orignal engine correct? seems kinda weird. Unless someone swaped the sensors them selves.... did you acctaully try swaping the connectors and driving? I'd say the coolant temp sesnor is bad get a new one i don't think they are that expensive at all. Possible crack in the intake hose between ur mass air flow and throttle plate... check for leaks. you still have your egr unplugged right? To reset the computer you pull out the EFI fuse for 20secs or more. if your tps is perfect i don't know how its still throwing a code.... possibly dirty, try cleaing throttle and plate and sesnor end. dashpot has nothing to do with it... unless its holding the throttle plate open. the coolant temp sensor should be the green connector. Have you tried beating on your mass airflow meter when its running like crap? This may fix it, and if the engine changes the way it runs by doing this i'd say its faulty and get another one. The air flow meter has a built in temp sensor for it as well along with many parts. if anything is stuck or sticking and or broke in it, it will give terrible engine performance. the temp sensor in the air flow meter works with the coolant temp sensor along with other components with the computer to know what kind of fuel mixture to use at the given time.

Kiroshu

Also with the timing. Your supose to set it exact to toyotas specs but i usually play mine by ear and how it runs. I say advance it anyway to where the engine runs its best.

BluVudu

I don't understand it running with the coolant sensor unplugged either but I just took it on a 70 miles ride and it ran almost perfect the whole way. I need to advance the timing a hair more. I did try swapping the sonnectors on the sensors and it ran worse afterward so I put them back and started unplugging everything that was throwing a code one at a time. I can get a coolant temp sens at Advance from Borg Warner for $23...not bad. Or Duralast @ AutoZone for $15... I will get the BWD...not partial to Duralast if I can help it. As for the air flow meter... I will check for leaks. When I hit the throttle hard, should I be able to hear the air rushing through it? It reminds me of cold air intake the way it sounds... didn't know if that was normal. I did beat on the maf when it ran bad but honestly it's not running bad at all now... just the hesitation when I hit the throttle too hard... when I'm driving, or idling, if I ease into the throttle, it runs perfect. It only stumbles when I hit it hard.

Kiroshu

i'd say your on the right track now. change the temp sensor or if your too worried leave it out if it runs soo much better leave it out lol. but um i'd get a new one. you might here some sucking in the intake its normal. but you should here no hissing souns that would indicate a leak. those main intake hoses are know to crack and leak mainly at the curved joints. just wrap some tape around em if they are leaking.late throttle response? loose cable?