99 Tacoma pukes, gags at 2000 rpm

Well The Igniter finally walked through the door, and yes it did come from the other
side of the Country !, Its OEM, installed it and went for a test ride, same problem, at
least now I know whats its not. Guess I will install the new OEM Dist and see what happens.

So I guess the Spark control comes from the ECU ( using sensor inputs ), then to the
Igniter, then to the Dist, then the plug wires, then the plugs.

 

The coil also sends a signal back to the ECU (through the igniter) verifying that the coil did in fact fire. If the ECU doesn't receive this signal back for a few sparks in a row, the ECU shuts the fuel injectors off (doesn't pulse them).

 

The first thing I replaced was the coil, not saying that its not the coil, but the problem didnt change at all
after the new coil. With everything I have checked or replaced I have the exact problem as when I started.
I know Im going to change the Dist, and Im still going to have the problem. And they say dont throw parts
at problems, give me another way.

 

1999 Toyota Tacoma still sick! Runs like a top up to 2200 rpm, then gags and bucks and halts, and will not go more rpms. Can back off to 2000 rpm and we are fine again. Thanks for advice. Truck is a 3.4 L V6 standard 4 by 4. Here's what I've done so far. Fuel pressure good, fuel pump new, PCV ok, cat converter is good, vacuum leaks..none, Throttle position sensor replaced, Mass air flow sensor replaced, timing belt good, plugs and plug wires replaced, ignitors checked, battery good. So tired of trying to solve this. Dealer struck out after a $350 stab at it. HELP

 

Sounds like it's not advancing the timing enough to me when you reach the rpm your speaking of. I'm very old school, back in the days of mechanical and vacuum advance, same symptoms.

 

Why are you thinking the cat is ok with 285 degress coming and going temps?
If the cat is working the heat difference should be around 100 plus difference from the front to rear,
My front cat is 300 degress and rear cat temp is like 480- 500 degress, if your at 285 front, 295 back might indicate a bad cat. Either way your numbers are not right on the cat, in order for the cat to clean
the emissions from the exhaust the cat has to be up towards 500 degress.
So maybe your cat is plugged but you should have a cell code,
Which means maybe the two O2 sensors are not working too???

 

So, great news.............I fixed it, thats right, back running like a little Tacoma should.
In the end it was the Dist, I looked at the old one, and it had no play in the shaft, gear
looked great, I had already replaced the coil, the specs weren't great, but the new one
did nothing, I had the same problem. Bought a brand new dist from parts.com. That was
560.00, but it was the whole dist with all the internals, and cap. Stuck it on today, went for a
ride tonight. And it runs perfect, no skips or bumps. I believe it was the Signal Generator
going bad, and intermittently not sending a signal back to the Igniter telling it that the plug was
fired, and when that happened, the computer would cut fuel quickly so the cyls would not
load up with fuel, but then it received a split sec later and it would add gas again, giving the feeling
of quick bumping , ever now in then, but it was getting worse.
But anyway its fixed. And Toyota could not find the problem. Shame on them. YEA
The Little Tacoma with 257,000 miles is back on the road again.

 

Dear GeDeuce,

Wow, you certainly have done your homework as far as trying to make your 1999 Tacoma run smooth again. Did you clean out your throttle body and idle air control while you were trying to solve your acceleration problem above 2,000 revolutions? One thing which I am sure you are already aware of when working on these old Tacomas is try and touch your coils the least amount possible, and stress them the least amount possible when working with them.

I was completely unaware the 1999sa had distributors. That is great this change worked for you. I have a 1999 with the same engine as you, and it has coil packs.

Good Luck,
Paul

 

Glad you figured it out, your input and output cat temps still don’t seem right. Just keep an eye on
that space if you need an emissions

 

Its a 1995, it has one Coil in the Distributor, And yes the throttlebody was cleaned out, and the Iac was also cleaned while I had it
off. I learned alot working on it, I owed it to the truck, Ive owned it for 23 years, and it has always ran so nice. This took
me to the very end of my ability. All along I was still able to drive it, but the bumping every now in then drove me crazy, and
I had to fix it, when I had come to the end of my knowledge I took it to Toyota, and they had no Idea, what it was,
basically they just wanted to start throwing parts at it. I decided if thats the case I can throw parts for less then 125 per hour.
So the only part bought and not needed was the TPS, tho I did buy a used Igniter off EBAY for 30 bucks, new costs 300 bucks,
and that wasnt needed either, at least now I have a spare for testing. Theres nothing like having your truck running like it
used to. And heck it only took me 5 weeks to fix the problem

 

We've got two different threads going here. I started this thread with the 1999 Toy Tacoma, 3.4 L, 4 by 4 gagging and puking once it hit 2000 rpm. The thread was taken over by a 1995 Toy, and its back on the road a gain. My original problem still exists...I'm also still working on it. I still solicit your help. Thanks all!

 

Think Im going to jump on pulldos Band Wagon, If you have a OBD2 reader that has live data look at your advance data. At Idle
you should be around 10, it should go way up when revved up even when your setting still. yes the bandwagon has
shaky wheels, but there are turning.

 

geduece, what happens exactly when you hit 2000rpm? is it smooth all the way up to that point? do you have hard starts or does it start easy?

normally when you hit an rpm wall like that consistently at the same rpm, its the crank sensor or something related to that.
In the case of the 95 taco that borrowed your thread earlier, the distributor houses the crank sensor on those engines, and I am guessing that fixed it.
on your engine, the crank sensor is located on the actual crank and you should see a connector hanging down by the crank pulley.

Sometimes the magnet gets weak for whatever reason or just dirty if there is an oil leak in that area or above that area.
Sometimes one of the wires going to it gets pinched and can cause all sorts of issues.
Alot of the time the bolt on the crank pulley is loose and the crank gear behind it that the magnet passes over is out of alignment etc...

I would first check that the crank pulley bolt is tight.
I would remove and inspect the crank sensor, along with the wires going to it, and especially the connector.
you can test the resistance to see if its in spec, or just replace it.

Now if you were having hard starts and the rpm where it breaks up isn't always consistent, i would suspect a leaky fuel injector.
your issue sounds more like the crank sensor to me.

If you had a timing belt job, then I would verify that the timing belt marks all line up (as in it was done correctly), and if not then get that fixed because it could cause it also. assuming everything installed right, I'd take a closer look at that crank sensor and crank pulley.

If you actually had a misfire, as in the ecu tried to fire off the plug but couldn't, you would get a misfire code almost right away and a blinking check engine light. to me it sounds like the crank signal is dropping off, so it wont even try to fire off the plugs and hence, no misfire codes. unless the crank signal is missing for like 6 seconds at a time, you probably wont get a code for that either cause it comes back as soon as the rpm's dip it sounds like. If you scanned the car even without the check engine light on, you may find an intermittent code in there somewhere pointing to the cause.
good luck!

 

Actually my Crank sensor is mounted in the block, right by the Crank, basically under the Alt Bracket.

Inside the Dist you have the Coil, the Signal Generator, and a resistor. I believe my problem was the
signal generator starting to break down.
This is a 95 2.4 engine
2JHilux.Great Post, alot of info there to digest.

 

Looks like you are right on that, just the cam sync is in the distributor after looking it up.
I'm used to the 2jzge distributor motors that have the crank sensor there also I guess.

The issue still sounds like it could be a crank sensor, but could also be a cam sensor issue also.

 

These trucks are old enough that the computers just dont put out the info you need
to troubleshoot problems, You take it toyota, and they dont really want to do anything
that would be troubleshooting, and they just dont do that anymore. Finding certain
problems can be a nightmare. They always say dont throw parts a problems, but it
looks like there is no other way. The Signal Generator Ohmed out to be in specs, tho
It was causing the problem. In the FSM there is 22 PIDS that you being the customer
can not get. Those would of spelled out my problem. Actually if you had a Scope you
could test almost everything. In my FSM it dosent show a Cam Sensor inside the Dist
or in fact anywhere on the truck. I wanted to check it, but never seen one listed for
this engine. Saw it listed for other engines used in this truck, but not for the 2.4. One thing
I did find out, after troubleshooting this kind of problem, you learn alot.

 

There's always a way to test prior to replacing parts, but not everyone is experienced enough including me... Check out South Main Auto Repair on Youtube - the guy never guesses on a part.

Read through your post and saw you figured out one way you could test...

 

Dear GeDeuce,

I am sure you are very frustrated with this RPM nightmare your truck has been giving you, and you are equally frustrated with the fact your 1999 Tacomas thread was inadvertently sabotaged by a 1995 Tacoma with similar problems. The advice about the crank sensor that 2jHilux gave you is excellent advice. I certainly would explore this possible crank sensor being your problem thoroughly. Please take the time now that the focus is entirely on your Tacoma's problem to educate us again on what parts you have replaced. This will help us to aid you in getting to the bottom of your Tacoma's dilemma.

Please also remember that these Toyota Tacomas are now older than hell as far as the automotive world is concerned. Dealers don't want to deal with these rigs anymore because their computers are no where near as sophisticated and precise as newer generation Tacomas. When was the last time you heard of the service manager and the lead mechanic at a dealership getting together to try and troubleshoot a problem on an old Tacoma. It just doesn't happen.

First generation Tacomas still being on the road is also the last thing Toyota wants to hear about or read about. Do you thing Toyota wants to hear about one of their 23 year old designs still being used today. No, they don't. They don't want to be in competition with themselves in selling new Trucks. This is the last thing they want to hear. They want the American public to constantly buy new just like any other corporation.

Take it easy,
Paul

 

That is a good call - especially the visual inspection part of it.

 

Eric is one of most favorite You Tube channels, he rebuilt my 280zx calipers in one show, When you have 20,000
dollars worth of test equipment and a vast knowledge as Eric does, you dont need to throw parts,
In saying that, I have seen in a few videos throwing parts. But his throwing parts and the normal DIYer is quite
different. I tested my Signal Generator, and it showed to be ok, but in fact was not. It showed good, but
intermittently going down the road it would falter. I went by the FSM to test, how else should I have tested
it, Heck a Toyota "Master Tech" could not find the problem. When it comes to intermittent electrical parts,
and you dont have a scope, even if you have a "Dealer Level" scan tool, these older computers dont give
you the pids you need to troubleshoot your problem. Thats why Toyota could not find the problem, he
basically said that the computer was not new enough to give him the info he needed, and actual
troubleshooting just wasnt in there Job Description any longer. I think one good way would be to
gather parts from wrecked trucks, like computer, igniter, Dist, crank sensor, all the electrical stuff
that fails, and just store them away so when you have a problem, your not putting out alot
of money to test. I have owned and still own a 280 Datsun ZX, these are computer controlled
and have no way to hook any reader to them at all. You are in the blind. So troubleshooting
components becomes a way of life.