check timing, mine missed a little bit cause the guy i bough it from had the timing at waht looks liek it could have been about 20 instead of 12.

 

My timing is at about 13 degrees. I really dont think its my timing. The only thing i wanted to mention is that i have no codes but if i leave the jumper in the diagnostics box and it will blink rapidly saying no codes until i rev the engine a bit then all the sudden it blinks a code 51 and within 5 seconds it clears itself of the code and blinks rapidly again, and i can repeat this as many times as i feel. Its really odd. Could this be related at all?

 

Code 51 as well as code 53 are the 2 codes that are NOT recorded in the ECU memory when a malfunction occurs. Code 51 is "Switch condition signal" which is displayed when the A/C is on, IDL contact off, ( it's in the TPS) or shift position is in R, D, 2 or 1 with the check terminals E1 and TE1 connected. Things to check for a 51 are: 1) A/C switch circuit, 2) TPS IDL circuit,
3) Neutral start switch circuit, 4) Accelerator pedal, cable and
5) the ECU.
I don't think you have a 51 because to properly obtain a diagnostic code you have to have the following conditions:
a) battery voltage above 11 v
b) throttle valve FULLY closed so that TPS IDL contact points are closed.
c) tranny in N.
d)all accessories are off.
e)engine at normal temp.
You are suppose to check with ignition ON, not with engine running. You're checking with engine running and with throttle valve not being kept closed so that the IDL contacts are not staying closed giving you a false 51.

 

Yeah thats a good point, Im not sure why its giving me that code, its not really any concern anyways i just thought that maybe it was related to my miss at idle. The miss isnt that bad but its annoying cause its there. It doesnt do it cold but its like a little puff every 10 or 15 seconds when its idling when warm at like stoplights and stuff. Thanks so far guys.

 

don't worry about the code 51 poppin out when u hit the gas!
i thnk u should check ur spark plugs. make sure they are correct gapping.

 

I just rebuilt the engine. Everything including plugs and wires and all ignition components are brand new.

 

make sur eyou don't have a bad wire that is shorting out somewhere. It does happen frm time to time with new wires.

 

so.. what is the status of this situation?

i too have the same issue..

 

I've had simliar issues. In all three cases they were related to either

1) Cheap copper plugs. Skip the autolites, buy NGK plats or iridiums. For those who care to differ, what did toyota put on the car and, please, find one current production automobile that still uses copper plugs.

2) Bad coil packs. While the packs "passed" the toyota shop manual test, further inspection revealed small cracks on the bottom of the coil.

I cannot be certain, but it seems that heat causes these cracks to expand and, ultimately, shorts out some of the spark when the engine is hot. If you run good cold/cool, but like crap after heat soak/long distance driving, check the coil packs.

The packs can be easily removed with an allen head.

Good luck.

BTW, don't buy new packs. Junk yard a couple of sets of three and you will probably get 3-4 good ones.

 

Thanks for the awesome reply, well two things, first off is i tried running a different set of coil packs on my car and it didnt change at all, but i guess that doesnt mean the other set that im trying now couldnt have a crack in one coil either. Are these cracks visible at all?? Cause i have two sets of 3 coil packs here if i can make one good set out of the two but how do you know which ones are no good? Also the second thing is as you know everybody seems to urge again platinum plugs for some strange reason so when i rebuilt my engine i just decided to go for some NGK Coppers even though they call for platinum plugs right from the factory manual. Maybe i will try changing plugs as well as making up a good set of coils if you dont mind telling me how to find the bad coils, thanks alot And yes my car idles like a dream when its cold, its only once its warmed up or hot that it starts to develop this "miss". Let me know what you think!

 

i recently did my HG and got it running. but i noticed the idle was slightly erratic. i adjusted my timing and most of it went away. im not quite sure what my timing is set at now. give it a try. loosen up your cps and turn it slightly. see if your idle smooths out. if it doesnt, at least youve eliminated one possible cause. and it only takes 5-10mins.

 

Nah, i know its not my timing, i have played with that many times, its set to 13 degrees right now but it likes it there.

 

same thing happen to me sometimes i idle @ 950rpm but sometimes is normal @ 650rpm

 

This is happening to me, i think it might be a sticking ISC valve. And to the guy who said to skip the cheap copper plugs, I have been running autolite coppers in my car for 30k and they are the best performing plugs it has ever used. Most high horsepower turbo guys are running coppers because of their heat dissapation properties.

 

I have currently replaced my ISC Valve due to another surging issue that has been dealt with, so i dont think thats my problem either. Its really odd. Seems to just have a little miss once its warm, and under load there is no miss at all.

 

maybe is our weird weather causing all of this

 

I also have the same problem. Slight miss at idle when warmed up, no miss under load, perfect idle when cold. No codes. I installed copper autolite plugs (3923) and new NGK wires. All new vacuum lines (-550 mmHG at warm idle). Cleaned out the ISC valve and PCV lines, checked the TPS for spec, checked O2 sensor for spec, replaced the fuel filter and had the injectors cleaned where they ran a couple of cans of cleaner directly to the fuel rail. Also checked the coil packs per TSRM. Problem is still there. Did not remove the coils for visual inspection of cracks though. Will try that next.

 

SAME WITH ME when my engine is warm is like 950rpm but when is cold is normal 650rpm

 

XScurry, definately let me know what you find with your coils, or if you solve this problem before i do please pm me and let me know what you did, cause it sounds like we have IDENTICAL issues here. I will do the same for you. Thanks.

 

Will do. Another thing I did thinking it would help was add extra and replace old ground wires on all the major points, no dice.

 

I had been using iridium spark plugs and always had a rock solid idle and great performace, but recently I made a switch to copper plugs. I now have a simular miss at idle... my .02

 

Thats now two people that say try switching to platinum or iridium sparkplugs, i might just have to do that i guess... just doesnt really make sense thats all? But it might be worth a shot. I just heard nothing but good about copper plugs even though they are cheapest so i thought id give them a go. So thats what im currently running. The factory service manual does call for platinum plugs though so maybe that could be it, i dunno. Thoughts?

Also, jkturner could you please explain how to tell if the coilpacks are good or not if they pass the test explained in the manual?

 

The test in the manual will check for major failure of the coil packs, but may miss intermittant failures related to underhood heat. The problems I have had appear to be related to cracked coil packs. The seem to work great when the engine is cold, but once it's hot the idle will surge and wander a bit.

There is not good test because the actual voltage that the packs fire is MUCH higher than what you will get from applying a 3 volt battery. (For the electrical engineers in the bunch, its leg megging a 10KV cable run.) I don't know of a good test for this except visual inspection. Maybe looking for a light blue glow between the coil pack and grounding plate while the engine is idling would be close. I'd say its easier to inspect and swap with a known good coil (or two).

My 91 had two cracked coil packs. I swapped in one good one the first pass and the problem persisted, but was not as consistent. The second pack solved it immediately.

I don't know if this is the source of your idle problems, but I can say that it is likely.

 

It defintely sounds likely, thats for sure. Im just not quite sure how to tell which coils to try changing over? I cant see any visible cracks in any of them if thats what you mean?

 

doesnt work i switch mine to plat and it didnt made a difference