1992 4.9 i6
#1
1992 4.9 i6 crank no start
Have a 1992 f150 in-line 6 have not turned it on in 10 years until recently surprisingly cranked but didn’t start so I changed the fuel pump checked if It had spark it did had good gas pressure it cranks good just won’t start I add starting fluid and it wants to turn on I’m just really confused any ideas?
Last edited by jesus.14jesus@icloud.com; 03-21-2022 at 07:02 AM.
#2
Need to know the facts. Just saying "checked good" means nothing. Did you get ALL the old fuel out?? Did you have 45-60 psi of MEASURED fuel pressure on the rail??Does the pressure hold afterwards? Pull the vacuum line off the fuel pressure regulator, is there gas present?Did you change the fuel filter?? Does the engine want to start if you cycle the key on and off several times before attempting to start?
Last edited by raski; 03-21-2022 at 03:58 AM.
#3
Need to know the facts. Just saying "checked good" means nothing. Did you get ALL the old fuel out?? Did you have 45-60 psi of MEASURED fuel pressure on the rail??Does the pressure hold afterwards? Pull the vacuum line off the fuel pressure regulator, is there gas present?Did you change the fuel filter?? Does the engine want to start if you cycle the key on and off several times before attempting to start?
sure did pressure is at exactly 55 can also hear injectectors spraying yes cleaned the tank and added fresh new gas ,filter also was changed have not pulled vacume line will try that Later thanks!! And only when I add starting fluid it wants to start but not without it and yes would cycle key to get the air out if fuel rail until It had gas
Last edited by jesus.14jesus@icloud.com; 03-21-2022 at 07:02 AM.
#4
It seems you have what is needed. Adding starting fluid with normal fuel pressure may indicate a bad vacuum leak. A stuck open EGR valve would prevent the engine from starting. You might try a gentle tap on it with a hammer. I seen it happen once on a 4.9, the pintle on the EGR valve had a hole burned through it. The engine would not start. The other might be the large hose going to the brake booster. The smaller lines won't keep the engine from starting. If the timing gears jumped, that would also keep the engine from starting. A compression test would verify it. Hopefully, you didn't mess with the distributor's position.
#6
Can you remove one or two spark plugs after you attempted to start it?
Are they wet or dry?
If wet , it could be no spark or flooded,
If dry , not getting fuel to the cylinders.
Depending on the answers to those questions will determine where we go next.
A WORD OF CAUTION,, MOST FOLKS USE TOO MUCH STARTING FLUID AND THAT CAN DAMAGE THE PISTONS .
Are they wet or dry?
If wet , it could be no spark or flooded,
If dry , not getting fuel to the cylinders.
Depending on the answers to those questions will determine where we go next.
A WORD OF CAUTION,, MOST FOLKS USE TOO MUCH STARTING FLUID AND THAT CAN DAMAGE THE PISTONS .
#9
You cannot jump start the computer.
A common issue with these older computers are leaky bulged out capacitors. After disconnecting the battery, remove the cover off the ECU. If any of the three caps are visually damaged, replace them or the computer assy.
I wouldn't remove the fuel rail at this time because I don't believe the injectors are at fault.They are very reliable.I am also assuming you have good spark plugs.
A common issue with these older computers are leaky bulged out capacitors. After disconnecting the battery, remove the cover off the ECU. If any of the three caps are visually damaged, replace them or the computer assy.
I wouldn't remove the fuel rail at this time because I don't believe the injectors are at fault.They are very reliable.I am also assuming you have good spark plugs.
Last edited by raski; 03-21-2022 at 03:53 PM.