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Skyvisions, ASE Certified Technician
Category: Toyota
Satisfied Customers: 14505
Experience:  Toyota Master Diagnostic
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Toyota T100: I have a 1994 toyota t100 with a 3.0 liter v6.

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I have a 1994 toyota t100 with a 3.0 liter v6. The other day the truck started losing power and just shut off and would not start back up. The engine turned over just fine and there was plenty of gas. Once I got the truck home I changed the rotor, cap, spark plug wires, and spark plugs. Once that work was complete the truck finally started. It starts hard and runs rough once you come off of idle. I checked my plug wires and made sure that they are wired properly. I'm not sure what to do to fix this, what should i check next.
Thank you for choosing JustAnswer and allowing me to help you resolve your Toyota questions! Have you checked the cylinder compression or have you checked for any malfunction codes that may be set in the computer? How many miles are on the truck?
Customer: replied 4 years ago.

I have not checked those items. The truck was running fine and just stopped. Once I replaced the items I mentioned i got the truck running but is still starting hard. It kindof sounds like it's timing or a couple of sparkplug wires are crossed. I checked the wiring and it is correct.

Customer: replied 4 years ago.

it has approximately 230K miles of the truck

The reason for running a compression test is to confirm whether not you have at least 170 PSI. If the timing belt jumps time it will cause it to run difficult and almost seem like the plug wires are crossed. If the belt jumps time the compression will drop. Did you check for any malfunction codes that may be set in the computer?

Customer: replied 4 years ago.

No i do not have a scanner that will connect to this year of truck. Sounds like i need to take it to the shop and have them check the codes, compression, and possibly replace the timing belt.

You do not require a scan tool to check for codes. All you need is a jumper wire. When the key is in the on position locate the diagnostic check connector box over by the battery and fuse box. Open the lid of the DIAG box and inside the lid you will see a map of the pins. Place a jumper wire in the pins marked TE1 and E1. Monitor the check engine light. If there is a code 12 for example the check engine light will flash one time then two flashes. After a 3 second pause the system will repeat itself. Let me know if this something that you can do. A small paperclip will work in place of a jumper wire or cheap speaker wire.
Customer: replied 4 years ago.

ok, give me a few minutes

Customer: replied 4 years ago.

It shows code 14

If you remove the negative battery cable for about 5 min. then reinstall it turn the key to the on position with the jumper wire in the terminals as I described does the light flash steady and continuous? Then try and start the vehicle and let it run for a little bit while running rough turn the key off then repeat the process then recheck for codes does the code 14 come back?
Customer: replied 4 years ago.

I'll get back with you once I completed this.

Customer: replied 4 years ago.

I followed your instructions, after the first time i disconnected the negative side of the battery for 5 minutes and then reconnected it, i turn the switch on the the check engine light flashed continuously, i started the truck and let it run for a few minutes, once it comes off of idle a little it started running rough, i then disconnected the negative side of the battery for 5 minutes and check for codes. The check engine light is still blinking continuously.

Just a little clarification I need you to get the vehicle to run rough for several key cycles do not disconnect the battery once the code was cleared. By the light flashing steady and continuous this means the code was cleared I'm trying to see if the code will reset after one or two occurrences of the vehicle running rough do not disconnect the battery cable any further and re-check for codes.
Customer: replied 4 years ago.

ok, I will let it run rough for for a couple of minutes, turn it off and do it again right?

That is correct were trying to see if that code 14 is the current problem or was it set due to a previous malfunction which theoretically should cause the vehicle to not run at all. But in some cases I have seen where it will cause it to run rough. I'm just trying to get you to duplicate the code 14.
Customer: replied 4 years ago.

I let it run rough for a few minutes, turned it off and did it again. During both times the check engine light blinked continuously. I noticed the O/D off light was blinkly faintly.

The overdrive light will flash also when the jumper wire is installed. Remove the jumper wire and allow the vehicle to run rough over couple of different drive cycles or key on and idling rough situations then reinstall the jumper wire turn the key on and see if the check engine light continues to flash fast.
Customer: replied 4 years ago.

ok, the light continues to flash

One of two things has to be happening here. Either the vehicle has an issue with the timing belt and the compression is low causing the rough idle and difficult to start or the code 14 is an intermittent problem and is unrelated. The code 14 means the computer did not see ignition confirmation or the ignition trigger did not get sent to the igniter. Typically when a code 14 is set you will not have any response from the engine at all other than crank and no start. The code 14 will eventually have to be dealt with. This could be anything from a bad igniter to possible problems in the wiring. It is difficult to diagnose the circuit without an oscilloscope. Without being able to run specific tests such as compression test and checking the timing between the cams in the crankshaft i.e. the timing belt it is difficult to say what exactly is going on here. It's always best to know one's limitations. Let me know how you'd like to proceed.
Customer: replied 4 years ago.

could it be the fuel filter or fuel pump

With the mileage that you have on there it's possible that the fuel filter has never been replaced it could be restricted. Likewise it the fuel pump is not pushing enough pressure it will cause it to idle rough and hesitate severely. The only way to know for sure is to pull the fuel pressure line off and see if it is putting out volume then check for pressure. It should be right around 40 PSI. Anything below 30 PSI and you will start to have difficulties. even with the kind of mileage that you have on this these pumps are not normally an issue. I would be more suspicious of the timing belt jumping time.
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