HollieJayyy

Im new to this but I have a 93 Toyota 5 speed pickup and just recently it has started messing up. When I pull off and shift through third its fine but as soon as I hit third it starts hesitating and my check engine light flickers on and off once I steady my speed its fine until I shift to fourth and it does it again. If i punch the gas it really starts jerking i have to gradually gain speed. I was afraid my transmission was slipping but I had it checked and they say its fine. Nothing shows up when they check the engine light BC it only flickers on and off. I have poured over the internet and came across this site and everyone here seems like they actually know what they're talking about. I know very little about vehicles. I've ran anything from it needs transmission fluid to a new a clutch to the fuel cleaner to a tune up to all that's wrong is bad gas. Any info on this would be amazing where I could get some kind of idea what's wrong since the shop can't find anything wrong with it.

19864runnerHawaii

check your plugs? maybe injectors? O2 sensors? Other than that im stumped as well, sorry I couldnt be of more help.

JohnnyCanuck

Welcome to Yotatech. Is there a reason that you might have a tank of bad gas, filled up somehwere you don't usually fill up? Sounds like a fuel supply issue, if I'm understanding your post correctly, it happens under load. Check your fuel filter/pump; others that have had this issue will chime in.

HollieJayyy

Thanks for all the help yes I did get a tank of gas where I usually don't that may very well be the problem we recently just had a winter storm some snow a lot of Ice and freezing and that's when my truck started acting up would that have anything to do with it.

RJR

Sounds like a fuel problem to me as well. Is it still cold where you are? Could be water in the gas freezing in the fuel line or filter. Try to let it sit someplace warm overnight if you can. Run a couple of tanks of good gas through it and see if it clears up. Change the fuel filter and cut open the old one to see what's trapped inside. If it's full of junk, you might have to flush out the tank to solve the problem permanently.

It's not the clutch or the transmission fluid; don't let anyone take you down those roads.

Try the easy things first and report back. Good luck.

RJR

Doing some reading in the service manual, it appears that if the ECU detects the following problem (code 53) "Engine speed is between 650 rpm and 5,200
rpm and engine control module (for knock control) malfunction is detected", the check engine light will blink but no code is stored. This matches your original problem statement.

This would be consistent with the problem happening under load, since knocking is more likely to occur under heavy load. The ECU will severly retard the timing (making the engine run like crap) to save the engine if the knock control system is defective.

Note: This is different from code 52, which says that "With engine speed between 1,600 rpm – 5,200 rpm, signal from knock sensor is not input to ECM for 6 revolutions." Code 52 is a sensor communication problem, and is stored, whereas code 53 apparently indicates an inability of the ECU to control knocking, and is not stored.

I'm not sure just what this means as to a fix, but you might want to have the knock sensor looked at if you can't find a problem with the fuel system.

HollieJayyy

I let the gas run almost out got a new tank of gas it wasn't the gas I don't think. We've checked my spark plugs and wires everything seems fine with them. My boss told me a friend of his has a Toyota same make and model as mine did the exact same thing and he replaced the knock sensor as someone just said but everything I've read on the sensor says it'll cause your engine to knock like a cracked or blown head mine isn't doing that. And it seems to only do it if I drive it longer than 10 15 minutes once my engine gets warmed up. We are doing a tune up now to see if it fixes the problem at the shops don't know what's wrong the Toyota dealership offered to replace the motor to see if that fixes it. I was like OK you don't know what's wrong but you wanna replace the engine for well over 5 grand no thanks .

RJR

A new motor! Seriously!!?? What a bunch of shysters!

Generally when an engine runs fine at light loads but stumbles at heavy loads it's a fuel delivery problem. The engine load is pretty light when accelerating in 1st and 2nd gear, because of the mechanical advantage of the gearing, but as you go up in gears, the engine has to work harder and will be wanting more fuel.

Weak spark can also contribute to misfiring under load, because the spark plugs are harder to fire when the cylinder pressures are higher. A bad coil wire, distributor cap, or bad coil itself could be a possibility.

Things I would check, that any good mechanic can do (and should have already done.)
- The fuel pressure in the fuel rail that feeds the injectors
- Change the fuel filter
- Check and/or change the distributor cap and the coil wire.

It's very likely not the spark plug wires, plugs, or a fuel injector, because that would usually only affect one cylinder and the problem wouldn't be so severe as you indicate.

It's also possible it's one of a number of sensors, especially since it only happens when the engine is warm. Possibilities include the knock sensor, EGR valve, ECT, and probably others. Figuring that out would require more careful hands-on diagnosis by someone who was actually competent and interested in solving the problem.

A bad knock sensor (or connection to it) won't cause knocking. Rather, the ECU will overcompensate for the lack of sensor information by retarding timing to ensure against engine-damaging knocking. The retarded timing will cause significant loss of power under load, so could be a cause of your symptoms.

Hope you get it figured out soon.

HollieJayyy

The dealership was more focused on the driver lol the mechanic couldn't believe it was my truck kept asking if I brought it in for a boyfriend or husband I had to keep telling him no this truck is mine he just replied with but its a stick shift like I shouldn't be driving it he spent maybe 10 minutes under the hood and I had to pay 85 just for that and all he could tell me was that he could just replace the engine that'd fix er right up like I was stupid. Sorry guys but they seriously try to pull one over on females lol

RJR

Seriously, that's just totally unprofessional. You should complain to the service manager, and/or the Toyota district manager. 85 bucks for no useful diagnostics and sexist insults to boot is simply uncalled for. I would expect a Toyota dealership to have higher standards than that. Certainly the one in Ft. Collins that I deal with occasionally has seemed much better than that.

HollieJayyy

OK guys I finally got my truck up and running. It was a temperature sensor paid like 20 bucks for it and some new antifreeze had to take my hoses off and stuff to get to it it was completely worn out. But we put it on there and its completely fixed it my gas milage is back great doesn't skip a beat now. And idk if it had anything to do with my heater or not but my heat will burn you out now.thank for everyone's suggestions and help. Especially for not making me feel like an idiot lol

RJR

Glad you got it figured out. Thanks for the update!