Does to me, they burn down...
Wont crank, odd situation.
- Thread starter 6894kevin
- Start date
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He has no power to the ECU that won't help solve the problem correct?
Emergency Troubleshooting Procedures - FAQ Item (Recommend Keeping Copy in Truck)
For updates or revisions, please PM me, nuclerlemon or semlin The below is a troubleshooting guide if your in the boonies to help isolate a non starting vehicle problem. This is a compilation from forum members, specifically RavenTai, KliersLC, Landtank and Beaowulf. This will not catch each...
forum.ih8mud.com
Let's work through the list.
Correct. So how do we check systems?
It cranks. Does not fire.
Oh.....Have you EVER unscrewed the two screws on the AFM/MAF/Whatever on the intake air hose and pulled on that harness?
check for spark.
Do you have a timing light?
Do you have a timing light?
Scenario 3:
Turn key, engine turns over but does not run:
Possibilities - Lack of spark from ignition system (Distributor) or lack of fuel. Note: Fuel + Spark + Compression = engine that starts, must have all 3.
* Compression does not instantly disappear without letting itself be known (big noise, big hole in side of the block etc).
* if no check engine light when the key is turned to on then the fuel injection system, more specifically the ECU is not powered.
* Check to see if there is spark via one of the three methods
o If there is a spark plug removal tool in the tool kit, pull a plug (#1 is easy) reinsert the plug into the plug wire and hold it against the motor so the plug gets ground, have some one crank the engine, you should see spark
o If you have access to a timing light you can check for spark without having to remove the plug
o Or, spark tool such as one from Harbor Freight:
* Check to verify Fuel pressure is present:
o Quick test for fuel pressure is to remove the return line from the fuel pressure regulator, it is a spring clamp right on top and easy to get to, all you need is the pair of pliers from the tool kit, after the line is removed crank the engine fuel should come out of the pressure regulator, if it does not you have a fuel problem, out of fuel, bad fuse, bad fuel pump relay, bad pump
o to find this line find the fuel injectors nestled in the valley between the intake plenum and valve cover, at the top of the injectors is the fuel rail it is cast aluminum, follow the fuel rail all the way to the front where you will find a tallish flying saucer looking devise, that is the fuel pressure regulator,
o where the pressure regulator threads into the fuel rail is high pressure fuel, at the top is a vacuum line, in the middle is the fuel pressure return that is the line we want to remove to check for fuel flow.
o You might want to remove the gas cap to relive any pressure so less fuel will come out when you remove the line.
o And of course be safe around fuel, For instance do the spark check first before you cover the top of the engine in fuel, also try to get as little on you as possible, if you do get fuel on you wipe it off ASAP, no need to turn a roadside repair into a visit to the local burn unit and a totaled cruiser.
o Another option is using the OBD II port with the ignition on a 96 and up. You need a scanner that monitors real time data.
o Check Fusible Links per below.
o (If other tests show no fuel present) Potentially fuel relay (located in fender) contacts are corroded. The proper way of cleaning a relay is with a burnishing tool. This is like a ultra fine very thin file specifically for relay contacts. Good luck finding one, I did and it was an hour away. So plan B, (not -B-), is to use an old trick I (Landtank) was taught back when I first started in field service.
What you need to find is a new match book. Cut the strike area out of the book and you have a very good substitute foe a burnishing tool. You slide the striker in between the contacts and the in a filing motion clean the contacts. DO NOT add any addition force to pinch the contacts closer!!! Once done on one contact flip and rotate the striker to clean the other contact in a clean area of the striker.
Turn key, engine turns over but does not run:
Possibilities - Lack of spark from ignition system (Distributor) or lack of fuel. Note: Fuel + Spark + Compression = engine that starts, must have all 3.
* Compression does not instantly disappear without letting itself be known (big noise, big hole in side of the block etc).
* if no check engine light when the key is turned to on then the fuel injection system, more specifically the ECU is not powered.
* Check to see if there is spark via one of the three methods
o If there is a spark plug removal tool in the tool kit, pull a plug (#1 is easy) reinsert the plug into the plug wire and hold it against the motor so the plug gets ground, have some one crank the engine, you should see spark
o If you have access to a timing light you can check for spark without having to remove the plug
o Or, spark tool such as one from Harbor Freight:
* Check to verify Fuel pressure is present:
o Quick test for fuel pressure is to remove the return line from the fuel pressure regulator, it is a spring clamp right on top and easy to get to, all you need is the pair of pliers from the tool kit, after the line is removed crank the engine fuel should come out of the pressure regulator, if it does not you have a fuel problem, out of fuel, bad fuse, bad fuel pump relay, bad pump
o to find this line find the fuel injectors nestled in the valley between the intake plenum and valve cover, at the top of the injectors is the fuel rail it is cast aluminum, follow the fuel rail all the way to the front where you will find a tallish flying saucer looking devise, that is the fuel pressure regulator,
o where the pressure regulator threads into the fuel rail is high pressure fuel, at the top is a vacuum line, in the middle is the fuel pressure return that is the line we want to remove to check for fuel flow.
o You might want to remove the gas cap to relive any pressure so less fuel will come out when you remove the line.
o And of course be safe around fuel, For instance do the spark check first before you cover the top of the engine in fuel, also try to get as little on you as possible, if you do get fuel on you wipe it off ASAP, no need to turn a roadside repair into a visit to the local burn unit and a totaled cruiser.
o Another option is using the OBD II port with the ignition on a 96 and up. You need a scanner that monitors real time data.
o Check Fusible Links per below.
o (If other tests show no fuel present) Potentially fuel relay (located in fender) contacts are corroded. The proper way of cleaning a relay is with a burnishing tool. This is like a ultra fine very thin file specifically for relay contacts. Good luck finding one, I did and it was an hour away. So plan B, (not -B-), is to use an old trick I (Landtank) was taught back when I first started in field service.
What you need to find is a new match book. Cut the strike area out of the book and you have a very good substitute foe a burnishing tool. You slide the striker in between the contacts and the in a filing motion clean the contacts. DO NOT add any addition force to pinch the contacts closer!!! Once done on one contact flip and rotate the striker to clean the other contact in a clean area of the striker.
- Thread starter
- #47
- Thread starter
- #48
Dont have a timing light...
Go through each of these. In order to verify each leg of the Fusible links.
Fusible Links and Relays
"Main" Fusible link, critical as it is upstream of the 15A EFI fuse under the hood, you can test this one from the drivers seat by turning on the radio, headlights, ac/heat fan, defrost, stop light, tail lights and telephone, if any of the above work then this fusible link is good,
"AM1" Fusible link, critical as it is upstream of the ignition switch and provides the power for to the starter solenoid, you can check this one from the drivers seat by checking the horn/hazards, dome light, diff locks, rear heat, turn signals, cigarette lighter, or wipers,
If you have the hazard & horn but none of the others check the big 50A AM1 fuse in the under hood fuse box (50A AM1 fuse not to be confused with the AM1 fusible link) Might not be a bad idea to stock a 50A fuse incase the big AM1 fuse blows
"AM2" is probably the most engine centric, it provides power to the ignition switch, the injectors, the igniter, the ignition coil, the distributor, and the alternator control system, if you get the yellow light on the volt meter with “key on engine off” this fusible link is good,
There are only three critical regular sized fuses required for the engine to start and run
15A EFI located in the under hood fuse box
7.5A Ignition located in the fuse box at the drivers knee
15A ECU-IG located in the fuse box at the drivers
Fusible Links and Relays
"Main" Fusible link, critical as it is upstream of the 15A EFI fuse under the hood, you can test this one from the drivers seat by turning on the radio, headlights, ac/heat fan, defrost, stop light, tail lights and telephone, if any of the above work then this fusible link is good,
"AM1" Fusible link, critical as it is upstream of the ignition switch and provides the power for to the starter solenoid, you can check this one from the drivers seat by checking the horn/hazards, dome light, diff locks, rear heat, turn signals, cigarette lighter, or wipers,
If you have the hazard & horn but none of the others check the big 50A AM1 fuse in the under hood fuse box (50A AM1 fuse not to be confused with the AM1 fusible link) Might not be a bad idea to stock a 50A fuse incase the big AM1 fuse blows
"AM2" is probably the most engine centric, it provides power to the ignition switch, the injectors, the igniter, the ignition coil, the distributor, and the alternator control system, if you get the yellow light on the volt meter with “key on engine off” this fusible link is good,
There are only three critical regular sized fuses required for the engine to start and run
15A EFI located in the under hood fuse box
7.5A Ignition located in the fuse box at the drivers knee
15A ECU-IG located in the fuse box at the drivers
Engine cranks but doesn't start good thread also after you check systems
FPR location
Guys,
With no CEL this engine will NOT run. No need to crank the starter.
Check fuses with a meter not your eyeballs.
Check for +12 on the brass colored phillips screw in the fusebox under the hood.
Check for +12 at the diagnostic connector on the firewall.
With no CEL this engine will NOT run. No need to crank the starter.
Check fuses with a meter not your eyeballs.
Check for +12 on the brass colored phillips screw in the fusebox under the hood.
Check for +12 at the diagnostic connector on the firewall.
Only thing we're not sure of is if the CEL bulb actually works. OP does not recall ever seeing the CEL lit.
Have a way to verify?
Going through all the fuses in the under hood fuse block.
Pulling each one and verifying continuity with a multimeter.
- Thread starter
- #56
Guys, how do I check this one? The normal fuses under the hood and in the cab all are showing good with the meter.
- Thread starter
- #57
Is there a way to check the fuseable link with the meter? 1st time I've ever used a volt meter sorry if it's a dumb question
- Thread starter
- #58
Got nothing at the diagnostic port on the passenger side?? I'm putting the red cord in the plug and ground on the engine block
You PULLED each fuse and checked it OUT of the truck, correct?
That's a relay. You will have continuity across two poles only.
You can check the fusible link with the meter.
Unplug the FL.
Set your meter to V-, 20.
Hold the black wire on the ground (-) terminal of the battery.
Touch the red wire on each of the ends (at the gray plug or the little black box) end of the FL. You should have +12V there at EACH of the wires.
Another way to test two out of three of the wires is to follow those items in post #49 that you don't need to use the multimeter.
