Big John

Hello....I just tuned up my 85 S-10 2.5 Lt. Engine, Manual Shift, with New Plugs, Wires, Rotor Cap, Rotor Button, Control Module, Fuel Filter, and ran fine for a few days, Yesterday it stalled on me going up a hill, what a delima with traffic behind me. I checked everything I could and found nothing, got it towed to Service Center. They unplug the Map Sencor and it started but had not power under excelleration, put on New Map Sensor, would not start, unplugged again and started right up, still no power. While it was at idle I pluged the Map Sensor up and Engine died. Well pulgged it in again and engine ran fine at idle, No Check Engine Light on anymore, which came on when I first encountered this problem. Truck will start and idle but when you take off it boggs down and won't go, does a lot of Bucking and Jerking. The Service Center here has no way to check for trouble codes so I guess I am stuck with it so far. Could the Fuel Pump be bad, Low Pressure or something? Any Help will be Appreciated, have to find another way to work till I can get this fixed. Thanks in Advance for your Replys and Knowledge.

Big John

EvansBlue

Do you know beyond a shadow of a doubt that all the plugs are gapped correctly and that the wires are on the right plugs? [/align]I'm thinking its either the fuel spider, or the sensors are going crazy because of excess gas fumes in the exhaust.[/align]

Big John

Thanks for the Reply.......Plugs are gapped correctly and plug wires in correct position, truck ran fine for a few days till this happened. Not sure what you mean by spider or sensors, are you talking about crank shaft sensor or oxygen sensor.

Big John

EvansBlue

Oxygen sensors. Actually not sure if the 85 is equipped with them or not...Going back on what I said, sinceyou confirmed that theignition is correct. I must have missed the part about the 2.5l. I was thinking 4.3l. Don't worry about the fuel spider. You don't have on on that engine. [/align][/align]Check your PCV valve for oil regugitation and also make sure you don't have a clogged cat converter. [/align]

Big John

PVC Valve is Okay, this S-10 Pickup has not had a catlatic converter in over 5 years, ran fine. The inside of the throttle body is good and clean, always used good gas, just don't make since. Does ayone else reading this know what may be causing my problem, too nice of a truck just to let sit. Guess I will check fuel pressure tonight and see what that does, will stop by parts store today and get guage.

EvansBlue

Have you checked for vacuum leaks as well?

Big John

Yes I have, found one line that had a crack in it and replaced with new hose, all others looked well. I changed the fuel Filter again but that didn't help either, checked the fuel pressure and it had 10 lbs pressure, according to what I have been told it should between 9-13 lbs. pressure, could the pump be weak and not supplying enough pressure when you accerlate?
I will drain the tank and try a new fuel pump and strainer tomorrow, maybe that will help, already got over $400.00 in parts and Labor not counting what it will cost me tomorrow, if it fixes it I will let you know, got my fingers crossed.

EvansBlue

Ok. I'm thinking you could still have dirty injectors causing at least part of the problem. [/align]You did replace the map sensor you mentioneddidn't you? Or at least clean the connector?[/align]

James Goble

Please Email me direct if you found the problem. I’m having the same problem. Have done everything that you have to fix it. My email Macgiver799@yahoo.com Thank you.