Sr5 Problem. - Toyota Nation Forum : Toyota Car and Truck Forums

Skylinegtrvspec · 11-23-2003, 09:38 AM

I have an 89 Sr5 and everytime i turn it off..well almost all the time...it diesel's...basically it keeps running without power...and if i even turn the ignition to the on position not start....it will start running again. I really need to fix this problem as my engine is starting to worry me...it is an old car. Anyway if anyone has ideas let me know ASAP

~Trev~

martiniracing · 11-23-2003, 05:06 PM

according to the toyota shop manual, dieseling is caused by EFI system problems and/or incorrect ignition timing

toyotaspeed90 · 11-23-2003, 05:46 PM

except that he has an 89.... which is carb'd..... and carb's actually will cause dieseling..... it very well could be your carb is going bad or needs to be tuned/rebuilt

AssDrag · 11-23-2003, 05:55 PM

what octaine gas are you using? try 89 or 92 might help. I think the 88 and up were fuel injected. only the older ones are carberated.

Skylinegtrvspec · 11-23-2003, 06:16 PM

It is carb'd. I don't know exactly whats wrong with it...it could be the carb is in need of repair...but ive also heard it might be a clogged cat or something like that....what should i ask the mechanic to check and is there anyway i can fix it myself...im kinda short on funds. Thanks for the help so far guys!

~Trev~

project trueno · 11-23-2003, 08:53 PM

don't worry too much, its common on aged carb'd cars

when it diesels, just stall it. Either step on the gas to burn off the remaining leaking fuel, or put it in gear....should die right away.

i'm guessing the problem is the carb, get it checked out by your mechanic. But one thing you could check is if the throttle plate is completely closed (sealed) when you're not on the gas pedal, because it could be "sticking" or stuck in a open position.

Skylinegtrvspec · 11-23-2003, 08:58 PM

Stupid question and im not a noob to cars lol...just to carb'd ones like my own...i have no idea how to check the carb for certain things...anyway can anyone just give me a lil pointer on how to check that plate? and any other possible causes are also welcome.

***Chris Corolla S*** · 11-24-2003, 11:11 AM

The throttle plate should be immediatley obvious after you remove the air cleaner assembly. It's a flap or flaps actually very similair to the throttle plate on a throttle body in basic appearance and function. You can just poke it and see what it does when you move the throttle cable to test it out.

Punisher · 11-27-2003, 09:31 PM

The only thing the '89 SR5 (4AF) has is an ECU.. no EFI setup it is carburated.

This is your problem(s)...

The throttle plate is being stuck open.. simple to check for
Just rev the engine and let off the peddle.. does it come back down to it's normal idle or does it slowly drop?

You may have a vacuum leak if so.. or the throttle plate may be stuck open.. use a good brand of carb cleaner and spray the outside as well... If you want another stock carb on it I have my stock 4AF carburator for sale.. it's in excellent condition.

Do any mods?

The problem could be the distributor timing.. you could try to advance the flame front of the spark plugs

Does it do anything else like stutter on the road?

It could be a blocked cat.. but give some more information to diagnose.

You can advance or retard the distributor timing by simply slightly loosening the distributor bolts so that you can rock the dizzy back and forth with some force.. then start your car up.. and if you push it towards the firewall that will retard it and if you pull it towards the bumper you will advance the timing.. You can advance it all the way and then bolt in place.. if you hear engine pinging then you need to retard it a little bit..

But give me some more information of the running characteristics first so I can pin-point the problem better