Hi,
I just bought my entry-pass to this forum as my first car and it works pretty good, considering its age. But I have one serious issue with it. When I'm at highway speed or at great load in town the engine literally "bumps" at about 2000 rpm. Once I release the throttle it's alright and once I put it down a bit so it goes to about 2500 rpm it's more or less gone.
I took it to a mechanic, but they said they had tested pretty much everything and were running out of ideas so I hope that someone here can help me, please. I don't want to blow up my engine after a month already...
I'm taking it back to the mechanic on Monday so I can ask what they did exactly, if that helps.

v6 or 4?

v6 or 4?

oh sry, forgot that. it's a four cyl and the mechanic said that I'm basically running on 3 cylinders but sometimes it's running normal on 4. really seems to come and go.

Ok, I went down to the mechanic today and he said they checked all the plugs, cylinder pressure, tested the resistance in the spark leads and cleaned the connections to the distributor. they said it would be something electrical.
On the weekend I noticed that it was at its worst when driving between 80 and 100 kph. then if you went into cruising rpms the engine would stutter badly, no matter if it went uphill or downhill, but uphill being even worse.
The check engine light hasn't come on at any point yet.
Anyone got any ideas on that, please?

Possibly a crack in the Distributor??.... Also, try changing the leads, just in case... I've seen a few times, the resistance of the leads when disconnected are fine, but tend to "blow-out" once driving.

ok. on the weekend I looked under the hood and I found that 2 of the injectors were pretty tight and the 2 others were twistable (one was really loose) and you could see and orange ring on them. how loose are they allowed to be or do they have to stay where they are?
also the mechanic told me I have rusty coolant, but he advised me not to flush it because new coolant would start leaking unless I changed the radiator. How bad is rusty coolant if I need the car up and running for only a year?

Normally injectors are a loose fit and can be twisted easily in their seats, but they shouldn't be so loose that they leak petrol or suck air. The misfire could be due to a faulty injector, or a buildup of corrosion in the connector.

Rusty liquid in radiator - lots of different metals in an engine - copper (if you have a copper radiator), steel, aluminium etc. Out of those, aluminium is the most active and the "Rust" in the radiator coolant is probably aluminium being eaten away somewhere. The corrosion of aluminium is worst where it is hot, and flowing quickly. Hence cylinder heads, thermostat housings etc tend to go first. You will know about it when you get a sudden leak or water starts to enter the cylinders. This can happen within 12 months of the coolant going off. Perhaps this has already happened and this is what is causing your misfire?
I would flush the cooling system and put in a good coolant to stop any further corrosion, then deal with whatever leaks occur. "Running for only a(nother) year" is being very optimistic, sounds like this 21 year old car has been very neglected. Still, good luck.

thanks to all of you.
for now the car runs good once warmed up.
but when cold it has really poor performance and sort of doesn't get over 1500 rpm with a randomly occurring clunk noise from the driver side. it is ticking as well when cold for about a minute or two.
once warm all of these symptoms are gone.

can anyone help me again please?

Have a look at the spark plugs. They will tell you a lot about the condition of the engine.

Have you changed the coolant yet?

Ticking is probably a tired cam chain.

Clunk could be the driveshafts.

Thanks for not giving up on mine, MadMax :) Yes I changed the coolant. I might need to reflush it once more, but it looks much better. And I got a somewhat thicker oil with 15w40. That sort of stopped it from blowing smoke on startup.
The clunk actually comes with a drop in revs of about 100 or 200.
The mechanic checked the plugs last week and said they were ok. Anything else that could keep my car from accelerating over 1500 rpm? If you put the pedal down it just starts to stutter. After releasing the throttle and reaccelerating it goes up to 1800 rpm for a split second then falls back to 1500. It seems as there were some sort of barrier it needs to get over, but it can't.

Anything else that could keep my car from accelerating over 1500 rpm? If you put the pedal down it just starts to stutter. After releasing the throttle and reaccelerating it goes up to 1800 rpm for a split second then falls back to 1500. It seems as there were some sort of barrier it needs to get over, but it can't.

Just curious did you have any luck since you last posted? I had this exact symptoms once in my old TR, after I had washed the engine bay the TPS (throttle position sensor) got wet and literally it would be rev limited to 1800 no matter the engine temp. I used an air compressor to blow it out and it was all good after that.

Sounds like you are losing spark when the ignition system is under load.
Ignition coil and power transistor are worth a look.
Get some from a wreckers and swap them over.

I suspected something like the coil already. I haven't tried it yet though. Can the coil run better once warmed? Because I only have these symptoms for the first 3 or 4 km. I also thought it might be something like the injectors or in the worst case the transmission because when cold, it stutters and hesitates and sort of bumps its way to city speed.
Where would the TPS be located and how can I reach it if I'm not experienced with repairs? Then I could have a look and see if it's that, but as the problem goes away once warmed up, but comes back when cold I don't think I have water in my system. At least not in the intake.

Can the coil run better once warmed? Because I only have these symptoms for the first 3 or 4 km.


Yep. A cold engine puts more stress on the coil because the mixture is richer and harder to fire.

You seem to be all over the place - you suspect coil, then injectors and then transmission, then TPS, then water in the system. Without actually checking or trying anything. lol

My money is on the coil and/or power transistor. Went through these symptoms with a TP 2.6, then TS 2.6 - second hand coil and power transistor fixed both.

Scientific method of trouble shooting - ONE thing at a time. Once you rule out ignition coil and power transistor, worry about what else it can be.

ok thanks so far. Yeah you have a point. I will have someone check on the coil and power transistor. Just out of curiosity, where would they be under the hood?

On the firewall, just above the passenger side front wheel on the 2.6 - on the 3.0L it is bolted to the back of the intake manifold.
Coil for the 2.6 - trace the centre wire from the distributor back, where it ends is the coil. It sits on a bracket bolted to the bodywork along with the power transistor.

http://t2.gstatic.com/images?q=tbn:ANd9GcTa8K4CgVqqeU5mPoIKS7MCoWEFLRt5K k0ib_i43fL9qNYs2YhC

Thanks, I will let you know how it goes.

ok. I had it checked today and they said it was not the coil. But they said the distributor cap and rotor are on their way out and the leads and plugs have gone high in resistance. I replaced the plugs, and they really did not look good at all. I will go to Hobart tomorrow and see if that changed anything. Otherwise I will start by replacing the other parts one by one. Any ideas on where to start?

Changing the plugs made quite a difference even though the misfires aren't completely gone. They continue to occur between 1800 and 2400 rpm. It's at its worst when the torque converter locks up during highway speed. 90-110km is pretty shaky especially when accellerating. Once it gets above 110km (2500 revs) it's going smooth again.
I ordered a new distributor cap and rotor plus new leads and see if that makes it go away.
Just one question: How can I replace the rotor? I only have a repair manual that states how to dismantle the whole distributor, but I won't need that much work, do I?

what ever you do dont remove the dizzy once you have the cap of the rottor will lift out
timing on the cap will be # 1 at the top clock wise #3 next then #4 last #2

Sorry for bringing this thread back to life, but I might need your help again.
What I did so far:
- Changed Plugs, Leads, Cap and Rotor, Fuel and Air Filter (all were in pretty bad condition, mechanic was actually wondering that the fuel could still circulate at all)
- Adjusted Timing to 5 deg BTDC with timing advance shortened
- Fuel Injector Cleaner used (two times)
- Checked Coil and Injector Resistance => all within spec
- Checked for Troublecodes on both ECU and transmission => all good
- All fluid levels are fine

Now, the misfires are gone, I can drive the car really well once it is warmed up. But during the first 5 to 10 minutes it still doesn't have power at all.
I realised that I have transmission drain back (the tranny fluid level is higher after the car is parked for a couple of hours, when hot it's at the right level), but I don't have slipping or any delays in engaging or shifting. The transmission is also not locked in a fail safe mode as it still shifts through the gears.
It's rather the opposite of slipping, the car seems to lock the engine and if you hit the pedal, it will start to sort of blubber without creating power. It does accelerate slowly, but seems to consume quite a bit of fuel while warming up. And I realised that it is still clicking for the first few minutes (clicking does get faster with higher revs).

Does anyone have any idea what that might be? Transmission? Torque Converter? Engine? Lifters? Valves?
Thanks for any opinions :) and sorry for the long post :D

Couple of different problems there.

The old 4 cylinder does use a lot of fuel when warming up. Big cylinders need a lot of fuel to run smoothly when cold.

Clicking is probably your valve lifters.

Ignition coil ok because resistance was checked with a multimeter? Common mistake, at 9V (battery inside the multimeter) it might test ok, but at the 400V primary voltage it runs on, it may be arcing over internally and put out a weak spark. Been there done that - try another from the wreckers.

NOTE: "sort of blubber" that your car is doing, is a misfire! You need to back to basics and check for things like a broken MAF, MAF plug and socket corroded, distributor plug and socket corroded, air leaks in the intake system etc.

Just to clear things. In the end, it turned out that a little more advance on the timing did the trick. Now it runs like a dream, plus fuel consumption is a bit down.

Now I want to take the old man for a trip on the mainland and noticed that my ATF has turned very dark red compared to fresh fluid. There is no problem with the tranny, but I want to treat it nice to get me to the gold coast. Plus I found green corrosion on some sensor connectors.
So if anyone still follows this,

-What type of ATF fluid should I get? And what should I be prepared to pay for just changing the fluid without taking the pan off?
-How do you get rid of corrosion from connectors?

Thanks guys..