altydog

I recently acquired a 1991 Toyota short bed pick up with 44,500 miles. 22 RE engine. Truck had been sitting for 3 years. So far, I'm running Techron in gas tank (new tank, sending unit, fuel filter), new rotor, cap, wires, spark plugs. Idles rough and sputters at exhaust.

Took it on a 15 mile drive on the Interstate to run Techron through fuel system. Starting pinging more as I went on but not constantly. Looked down and saw oil warning light on. Pulled over and checked the oil which was at normal level. Engine temp gauge was always in the normal range. Restarted it, oil light was off, drove it home on city streets and warning light did not come on all the way home. At cold start up, engine is noisy as if there is lack of lubrication, and lasts about 5-10 seconds. Any help would be greatly appreciated.

JasonYota

iTrader: (1)

Timing set correctly? Have you changed the oil?

altydog

Yes, I changed oil and filter. Checking timing next. Thanks Jason.

superex87

The noise at start up is a loose timing chain. Normally caused by a broken timing chain guide, do a search there is tons of info on these timing chains and guides.

On the oil light, check to make sure the oil filter is tight, nest to the oil filter is the oil warning light. Make sure the wire is firmly connected to the sensor.

If the engine is knocking you need to check the engine timing asap! If the timing is good you have one or more bad/ poorly performing fuel injectors. Do not drive the truck like this or you will cause sever engine damage.

skypilot

iTrader: (1)

Check the knock sensor too! wire may be broken or came off. You should consider pulling the injectors and sending them to witchhunters for a cleaning.

altydog

Took it to my mechanic. He dropped the pan and it was sludge, including 70% of screen. He cleaned everything up including passages. He installed a new oil pump. He put a new fan clutch on it. As to the miss, he said to put a product by Lucas in it that cleans injectors and carbon deposits and drive it. I've been doing this. Rough idle comes and goes, but does it most of the time. Hopefully it will get better as things circulate. Drove it steadily at 65-70 and the oil light did not come on.
I notice dampness on top of the charcoal canister even after I drive it. I notice that the idle will speed up and then suddenly settle down, but when the fan clutch kicks in it doesn't speed up but stays steady. Would the canister have to do with any of symptoms?
Finally, the noise today that I thought was a light ping/detonation I'm now thinking might be the timing chain/guide issue. Because when I have the hood up, and rev it some and let off I'm hearing the noise which I think I was hearing at steady highway speed. This engine only has under 44K on it. Is it normal for the guide to fail at that low mileage? When the mechanic had it apart to do the oil pump would it have been good to do the timing chain guide?!?

skypilot

iTrader: (1)

Well; yes that was the time to do the chain. With that much sludge in the pan, it probably did kill the chain. Probably did more damage too. I'm going to assume that those 44k miles were very hard miles and did not include regular oil changes. If you the valve cover check the cam lobes for wear too. Bet the tops show damage from lack of proper lubrication.

altydog

Yesterday, it ran the smoothest yet. No popping at the exhaust, engine smooth. Then last night I took it for a drive and it was, to me, starving for fuel. it was running horribly, rough and for the first time the Check Engine Light came on. I would think that if it were a vacuum leak it would consistently run rough. But since it was running so well for a while yesterday, I'm thinking it's fuel injector related, no?
Anyone know somebody that's a good Toyota mechanic in Palm Beach County?

altydog

Is there a code reader device for a 1991 Toyota Pickup (has EFI) or do you count the blinks on the Check Engine Light method, or either way?

skypilot

iTrader: (1)

Injectors are probably clogged too. I use Luca's brand stuff in the tank.

altydog

I learned about obtaining codes using a jumper. I get #25 and #31. Since the FSM lists several potential causes associated with each code, are there some things that are usually the culprit(s) and I could begin with them?

altydog

I tested the AFM in accordance with the FSM and help online and was able to determine that it was defective. I replaced it and it made a huge difference. Much more stable and it idles smoothly. However, when the A/C is turned on it idles too high and I'm still getting a slight ping.

skypilot

iTrader: (1)

You need to check timing and the knock sensor. You have to jumper the 2 pins to get the ecu to stop adjusting timing while you do it. Could also be low fuel pressure.

altydog

Idles too fast when I turn on the A/C

altydog

OK, I got a response that told me how to adjust the idle with the A/C on so that worked.
Bought a timing light, jumped out E1 & TC1 and timing was way off. So I got that done.
Biggest problem now is a tingley, metallic sound in the top end which I hear when I come off idle to say, 2000 RPM and when I back off. I'm wondering if it's the timing chain/guide issue. But two important factors to consider are that, although this is a 1991, it has than 44K miles. Secondly, it sat for around three years and when the mechanic pulled the pan it was sludge city. Since he cleaned everything and put in a new oil pump, I've driven it about 40 miles. Should I just run it and see if it clears up? A friend recommended marvel Mystery Oil as a product that would clean up the top end if it was added to the oil. Thoughts?

Shady Cadence

The timing chain issue isn't about wear, it's about materials and age. the guides have a nylon/plastic type material on the contact surface. While fine when new, over time it becomes brittle and prone to breaking. Once gone, the chain rubs on metal instead of plastic, and has less tension. Swap out the chain, sprockets and guides. Make sure your key way on the crankshaft is not worn, over time this will break your sprocket.

I recommend Sea Foam in the engine oil. Works wonders.