rstep1

I have a 1992 ES300 that is a very clean car, I love it. when I bought the car the owner told me that sometimes the car acts like it wants to stall and cut off after getting off of the highway. Well, I did not notice anything like that, but i did notice that sometimes when I am at a red light or whatever, the car would idle down like it wants to cut off. It did this several times over the last three weeks. Well today, it finally did cut off, and it would not start again. I have not had a chance to look into this, I am suspecting a bad fuel pump or something electrical. I did not get any check engine lights or anything prior to this happening, the car has been running fine with lots of power etc. Has anyone seen anythng like this before, is there something that is common on these cars that may of went out on me?

Pheonix

Very doubtful to be a bad fuel pump on any Toyota.
It's most likely a vacuum leak, or the IAC valve is clogged with carbon (from the EGR valve) and sticking.
I highly suggest you take the entire upper intake manifold off & clean the inside of it, the throttlebody, the IAC & EGR valves. (At the same time you can also very easily replace the spark plugs, see a previous post to my recommendation on what plugs to buy. And the distributor cap & rotor)
But start by cleaning the IAC & EGR valve & checking for vacuum leaks.


You reset the ECU by pulling the EFI fuse (fuse box nearest the battery) for a second & putting it back in. Then drive the stank out of the car for alittle while.

rstep1

I just did a test, I pulled one of the spark plug wires and connected a spark plug to it, turned over the car and I got no spark from that plug, I then tried another plug wire with the same result. In the morning I am going to check the distributor cap and see what it looks like, the only other thing is the coil/with ignitor that goes into the distributor, that is where the distributor gets it spark from. What do you think?

Pheonix

Did you have the spark plug grounded? If not, you won't get spark as the electricity has nowhere to go!
The toyota v6's will run pretty good on 5 cylinders. If it had droppd a sparkplug it'd be about as rough as a normal late model to old domestic v6 (No kidding aside, seriously!) and the ECU would sort of tune the fuel around it & bump the IAC around enough differently to maintain a stable idle without any major fuss. If it was grounded & you swear you had it all plugged in nice & tight, then ya look at the dizzy cap & rotor!


I still think you need to start with looking for a vacuum leak, & cleaning the IAC valve (which controls the idle).
All things start by cleaning the throttlebody, IAC & EGR valves. Simply put, if you've got a faulty idle & no vacuum leak. The Idle Air Control valve is likely stuck & not giving you a reliable idle.


If nothing else, it's routine maintenance on all engine's to clean such parts. especialyl if they have an EGR valve. As eventually they'll all clog with carbon. Doesn't amtter who makes it - if it's pumping spent exhaust into the intake - it's caking up!

rstep1

Yes, I did ground the plugs... still no spark, I am trying to take off the dist cap, but it will not budge, I have all three screws loose, is there a trick to this, I have never run into something like this before, the cap will not come off. Am I missing something?

rstep1

I just wanted to mention that my idle was not faulty, it actually ran very smooth, just intermitantly it would idle down, I would say maybe 10% of the time running the car. I just can not get the darn dist cap off, I do not know what else to loosen, doesnt look like anything else is there...

Pheonix

3 bolts & pull. Ofcorse it's stuck. It's probably been on there since 1992.

rstep1

What luck, I got the cap off, changed the Distributor cap and rotor, rotor looked really bad..... and it runs like a champ!!!! the only thing now is I think my car gets hot while I run the air, sometimes it doesn't, the fan constantly is on, is this normal? My overflow tank lets out anti-freeze, not all the time, just when it feels like it. I got a new thermostat, I have not put it on yet, temp indicator inside car shows normal... have you seen this before. I am so happy, she is up and running.... )

Pheonix

Change the thermostat, both pressure caps & flush the block & radiator of coolant.

• radiator may be clogged from not changing coolant enough
• thermostat may be stuck
• pressure cap may be faulty
• ignition timing may be abit too far advanced - if you've played with it, or nudged the distributor around any
• the fan may not be spinning up

With the engine running, connect OP1 & E1 in the Diagnostic port in the engine bay. If the fan spins faster, it's fine. If not, the connector for it ontop of the powersteering pump is likely unplugged.

rstep1

Thanks, I will do all of this, although the fan will spin faster as I excellerate... but I will go get the two pressure caps and change the thermostat and flush the cooling system, I already have it. Thanks again.