95 Tacoma Crank no Start

I have a 95 Tacoma 2.7L its been sitting awhile. I started up it up a couple of weeks ago. Got it going it had a miss in cylinder 3, but I drove it around and let it charge up the battery etc etc. I drove it back home. parked the truck, I changed out the spark plugs on it. after that the truck cranks but will not start. unless it has set for awhile, after it has set for a while like week it would start up and idle for a second or two then die again. so this lead me to believe its a fuel issue. 1. i replace the fuel pump relay under the hood, nothing I didnt hear the fuel pump turn on when the key is turned to the run position. 2. I dropped and replaced the fuel pump, still same results. I'm running out of ideas to look at, so I you have any experience troubleshooting with old trucks it would be greatly appreciated.

 

Could possibly be the crankshaft position sensor or camshaft sensor. These could also cause the misfire and a completely dead crankshaft sensor usually results in a no start

 

See I ruled that out bc it would fire up and run for a few seconds after it set for while like a week

 

I don’t think the relay will power the fuel pump until it sees a crank signal.
I’m not saying it’s the cranks signal.

There’s a lot more parameters that need to be met to keep the engine running.

ECT Sensor
Idle Air
MAF

 

I just swapped out the CrankSensor and no luck, Back to Square one. I'm not sure what to look at next. I'm limited on tools for troubleshooting, I still haven't listen to the injectors to see if they are firing. That will have to wait until I order a needle point style stethoscopes to do more on that. Its probably about time to order the actual Toyota Tacoma Manuals and go from there.

 

Have you checked:
Fuel pressure?
Power and Ground at the fuel pump when cranking?
Will it run if you spray carb cleaner in the intake?

 

I havent checked powered and ground yet at the Fuel pump, I dont have a voltmeter to check it and no spare hands either. before I changed the fuel pump, if it set for a couple of days it would start and run for a few second before dying again. like one of the injectors was leaking fuel (idk) but after changing the fuel pump no sucks luck, when I turn the key on I don't hear the pump do prime like it normally do. so scratching my head.

 

I don't think 1st gen Tacoma's have a key on prime, I know 2nd gens don't.
From the FSM:
FUEL SYSTEM > FUEL PUMP CONTROL CIRCUIT > CIRCUIT OPENING RELAY
Circuit opening relay controls fuel pump circuit. When EFI main relay is energized, EFI main relay provides battery voltage to circuit opening relay. When engine is cranking, circuit opening relay receives a start signal which energizes circuit opening relay. Circuit opening relay then provides voltage to fuel pump. When start signal is released from circuit opening relay, the circuit opening relay ground circuit is controlled at Engine Control Module (ECM) terminal FC.

You could do a bypass test on the Circuit Opening (Fuel Pump) Relay and see if the pump runs.

 

alright give me a crash course on how to do the bypass and ill go give it a shot.

 

Just stick a piece of wire connecting the power wires in the relay socket or just put 12v to the pump with a battery and some leads. You could have seen if the crank sensor was working if the computer was getting crank signal when cranking the engine with a cheap ODB-2 reader hooked up to your phone as I’m assuming you don’t have a tach on your gauge cluster.

 

You would take a jumper wire and jump pins 1 and 2 of the C/Open Relay.
Normally they are the 2 BIGGER pins. However, I’d feel more comfortable if someone could provide a Relay pinout. Just to be sure.

 

So have you tried spraying starter fluid in the intake to see if it tried to start? Have you cracked the fuel line banjo bolt to see if fuel leaks out? These are two very simple things to try to help narrow down the problem. If it tried to start then it is a fuel problem. If it still doesn't then it's an electrical problem. Also, try disconnecting the battery. I'm wondering if this "period" of sitting is just allowing some voltage to drain off enough that the ecm resets. Disconnecting the battery will simulate that.

 

Alright, back to this again. I just jumpered the open circuit relay from white/red wire to the blue wire. And nothing happened it just kept cranking again no start. Didn’t even hear the fuel pump kick on and prime. ‍♂️

 

If the pump isn’t running, you either don’t have power AT the pump or your ground for the pump is bad.

There is a slight chance your injectors aren’t pulsing. But I doubt it. You need to get that pump running.

 

Do you have power on the White/Red wire at the C/OPN relay with the key on?

 

Did you check your coolant temp sensor and fuel temp sensor?