my truck won't start. it tries like it wants to like it's not getting fuel. i put a new fuel pump on and still no go. the voltage at the pump is ignition on is 7 volts. that seems strange to me. i swapped a few relays around and eliminated that. i have 12 volts at the fuel pump fuse under the hood.

7 volts doesnt' seem right. what do i need to check?

thanks,
Joey

 

my truck is a 1998 f150, 4.6, 4wd, extended cab, long bed. the symptoms are just the same as a fuel pump. been down that road before. this one has me puzzled.

any ideas?

Joey

 

took the iac off and tried to start and no go. tries to start but stumbles. sounds like it's get juice to the plugs. 7 volts to the fuel pump puzzles me.

anybody?

 

check engine codes are 171 and 174. it's been like that for years.

anybody?

 

if it's not the fuel pump where should i look or check?

 

i changed the fuel filter about 6 months ago.

 

If you have been running 171 & 174 codes those are lean condition. What happens is the computer will richen the mixture to compensate so the motor is actually running rich. This is a perfect storm for cooking the cats.

If you can loosen the connection between the manifold and exhaust pipe and have it run better, then the cats are clogged.

You can also do a vacuum test at the manifold (intake of course) normal shoud be around 15-20 inches.

Read this link and see if anything fits your situation..... http://www.aa1car.com/library/converter.htm

Good luck.

 

i put new cats a few years ago.

 

i know it's about time for plugs. what should they be gapped at? i can't locate my manual.

 

i pulled a plug and it's gapped around .058. is that close?

 

i'm going to put a set of plugs in it and keep my fingers crossed. ugh! this thing is going to be a boat anchor real soon.

 

You can't measure the voltage at the pump with just the key to run.
The pump relay won't stay up long enough unless your looking at the voltmeter when some one has just operated the ignition or the motor is cranking over to restart the pump.
First thing is, do you hear the pump running at key on, for about 2 seconds? yes or no
Second have you looked at fuel pressure at the fuel rail with several key on cycles so the pump can build pressure?
Until you have these answers or your not going to know if it's a fuel/ pump issue or not.
Again the pump doesn't just run full time with the key on only.

 

ok. new plugs and plug wires and still no go.

 

Plugs .054 .Now answer bluegrass' questions.

 

i don't have anybody to help me and don't have a fuel pressure gauge. it tries to start with stumbling. black smoke pouring out. i'm thinking bad fuel with what i have to work with.