Ok so here is a quick review of what I have... I just purchased a 1987 4x4 toyota sr5 pickup with a 22re and a sas swap on it. I am planning to build it into a off road/on road rig. I am new to yotas and am on a steep learning curve coming from jeeps and land rovers. Now for the problem I am having, bought the truck and the guys said the fuel pump was bad we got it home and pulled the fuel pump found that it was not getting power. After alil of this and alil of that we hardwired the fuel pump with a toggle to get it running. We then drove it around checking to make sure everything worked (with very VERY old gas). When we parked it we cut the fuel pump off and the truck stayed running and when we listened in the tank the pump was whining. At this point and time the truck ran fairly well better than i had hoped. We then did a complete tune up plugs, wires, pcv valve, rotor button, dist cap, oil change, topped off all fluids, and drained bad gas added new with sea foam in it to clean the motor out. Now when driving the truck she sputters when taking off then runs great idles fine if you let her down to idle easy when idling it sometimes dims the lights and sputters when you give it some gas then revs up wonderfully. I would really like to get some insight into what is going on here. Could it possibly be timing, coilpack, charging system, or is it something seriously wrong. Like i said i am new to the yota world and am on a steep learning curve but am very mechanically inclined but just need to know where to go from here.

 

Did it start acting up after you did all that work? I'd start by double checking your work along with a close inspection of all the vacuum lines, plug wires, connectors, etc.

Also, You said very old gas. Did you change the fuel filter?

 

Check or change the fuel filter, located near the tank, had some problem.
also the tank may have to be cleaned. My Toyota was in a barn for 12 years.

 

I will change the fuel filter but it just doesn't make sense that that would cause skipping and also lights dimming at idle. I also did some troubleshooting today my new pcv valve is very loose also when I disconnect it the engine shuts down. When I remove the oil cap the motor drops in Rpm almost bogging down. At cold start engine cranks perfectly and runs perfectly. Pulled the error code. Blinked 11 times. Looked up said ecu power supply. Not sure if this could be the problem or not. Not sure where to look to fix it.

 

check the alternator, batt wires , ect . if they are bad or corroded then the truck is not running on full juice . start the truck unhook the bat. if the truck dies then you have a bad connection or the alternator is bad.. after the initail start up the truck runs off the alternator. if there is not enough power then the lights will dim, full pump not keeping right pressure , and coil not enough energy to burn gas . i hope this helps.

 

Ugh. Do NOT do this.

Edit to be helpful:

Removing either cable from the battery will cause a serious voltage spike and can fry the internal (or external, depending what vehicle) voltage regulator. No matter how you put it, removing either battery cable from a running vehicle is ALWAYS a bad idea.

Just use a DVOM and remove all doubt with actual data.

 

If it runs good cold and not warm maybe cold start injector?