Need help with 1990 f150 302 efi

[Mister Heavyhand]

Flush the gas tank(s), new fuel pump, relay, and filter.

 

[harrycalahan]

How many inches of vacuum at idle? Can you put a pressure gauge on the fuel system to monitor it real time?

 

[jeep78]

OBDII?

I had an engine bustin out at 3000 rpms. Stuck a real time reader on the OBD port and saw the timing go crazy about 3K rpms. Replaced crank sensor (no codes set for anything) and all was well.

 

[cjnowell72]

Check timing, crank, cam sensors? Specific tests to reads the ohms on the sensors to see if they are reading right. Could be bad tfi module too

 

[21SF]

How many inches of vacuum at idle? Can you put a pressure gauge on the fuel system to monitor it real time?

Dont know vac pressure ,put fuel pressure on rail stays at 35psi

 

[21SF]

Obd1

 

[21SF]

If any off you guys might be willing to come take a look that actually knows these motors I'll buy the beer ,I think I'm at the end of my knowledge, I took it to a mechanic 500 later he put a belt pully and clutch fan on ,needles to say I'm not taking it to a shop

 

[woodstock]

Have the 5.0 of around that time in my 71 cougar. I had ok performance from the stock emissions/computer set up but really woke it up with a Fitech fuel injection system, new intake, and GM HEI style distributor!

You can go that way, or ss others have said, you Have to know what your fuel pressure is, and engine vacuum is extremely important as well. It could be a simple vacuum leak too.

 

[8675309]

take out the oxygen sensor and take it down the road
if it improves you know what the problem is

 

[MRM]

A test light should be all you need to read the codes. You just have to jump the right pins and count the flashes.