Well, so far i have replaced the alternator, Gas tank and Fuel filter, Fuel Pump Relay, EEC Relay. The fuel pump seems to be working, it primes fine. Gonna check pressure soon. I just got the new tank and filter put on today, it ran fine for a little bit. i took it down the road warmed it up a bit, then went down to a friends house about 5 minutes if that away parked it for about 10 minutes. Started fine but within 30 seconds of driving i gave it gas and it just bogged. Let gas off ran fine for about another 500-1000 feet then pretty much died and kept sputtering. I cannot get it to start now and when it does it is bogging at like 400 rpm trying to get going...... Any ideas.... I am stumped.

1989 Ford 300CID 4.9L

I will check tomorrow if it starts.... see if it happens again... maybe only happening when warm?

started up this morning... ran for like 1 minute then i gave it some gas and it died...... Hard to start again... any ideas?

It seems to have had a tune up before i got it, plugs looks clean, wires clean, cap clean, looks good....

check engine light is not on.... i know pulling codes usually only works if light is on but what about memory codes? didnt think it came on if those were on.... recently got truck, ran fine for 4 days then last day i went 4x4'in in the snow it startted to crap out..... Tried starting when got home, flashed up right away., idle'd very ****ty like 600RPM or less and it would jump between 400-600 rpm. then died within 30 seconds or so.... gonna try pulling codes right now!

pulled codes with KOEO

51 - ECT Sensor Out of Range indicated/ circuit open
24 - Air Intake Charge Temp (ACT - IAT) Vane Air Temp Sensor out of range (VAT)
10 - No Idea what the 10 stands for isnt in my book.... at first i thought it ment cyl # 1 something was wrong, but then i seen that for it to read how the CYLS are it needs to be KOER and i did KOEO

so any ideas what should be done? can i buy these sensors or should i just replace the computer. Thanks!

Again, Tried starting this morning.... Flashed up right away... died within 30 seconds... idle good for 10, other 20 at about 500-650 ish

 

rough idle! any help aprreciated!

 

Odds both sensors died at the same time gotta be slim, possible yea but sounds unlikely, I'd test for reference voltage at both the ECT and ACT sensors. Unplug connector and with key on engine off test for 5v across the two pins in the connector.

Looks like they both share a common circuit tied in down stream of where others connect to it, may be a problem with the black white wire after that point.

 

sorrry, electronics are not my strong point lol. so, get a volt meter, unplug sensors, hook up volt meter, turn key on and see if it is getting power (5V)? where can i find ECT and ACT

 

Yes exactly you can also test the sensors with a multimeter if you find the reference voltage is good.

As for location I can't say for sure on the 4.9L but you'll find the ECT in a water jacket in the block, you'll find two, one with two wires connected to it and another with just one. Naturally your looking for the one with two wires.

The ACT should be in the intake or air tubing between the throttle body and breather box or in the breather box itself.

Someone with a 4.9 would be able to answer that with greater detail!

 

ok, one other question, whats the difference between ECT Circuit open, or circuit out of range.....

 

Open circuit is nothing no resistance, voltage, continuity.

Out of range is voltage or resistance higher or lower then a specified range the sensor operates at/computer expects to see.

 

so if it is open, it is getting no power?

51 - ECT Sensor Out of Range indicated/ circuit open

so its probably not getting power? gotta find where the wire loses voltage.... (thats where voltmeter helps to find if it gets poweer to wire i assume)

 

Yea a multimeter, even if its a basic cheap one, they are an indispensable tool working on these trucks. Trace down a electrical problem in a few minutes using three basic settings.

Voltage (AC and DC), resistance and continuity, they'll get you the answer to most problems encountered.

 

ok, does 89 4.9L have MAF... Lordco is telling me it doesnt but i swore it did....