89 Turns over, but won't start
03-07-2009, 07:41 PM
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89 Turns over, but won't start
I have an 1989 F150 with an I-6 and EFI. I can't get it to start. Here's what's going on, sorry for the length, but any help would be apprecitated.
After having my truck in the garage for a couple of months I started it up just fine without jumping it or anything. I went into the house to let it warm up and went back out after five minutes and it wasn't running any longer and I haven't been able to start it since.
I've disconnected the fuel line from the filter and fuel is pumping fine. I check one cylinder and I have spark. I replaced the spark plugs, but still won't start. Even though the fuel pump is pumping, I feel the engine isn't getting fuel because I cranked for several minutes, removed one of the plugs and they appear dry. I would expect fuel on them.
I've never dealt with EFI, so I really don't know what to check there to see if it is working or not. I'm an electronic technician so I feel comfortable if I know what I'm checking for.
I appreciate any help I can get.
After having my truck in the garage for a couple of months I started it up just fine without jumping it or anything. I went into the house to let it warm up and went back out after five minutes and it wasn't running any longer and I haven't been able to start it since.
I've disconnected the fuel line from the filter and fuel is pumping fine. I check one cylinder and I have spark. I replaced the spark plugs, but still won't start. Even though the fuel pump is pumping, I feel the engine isn't getting fuel because I cranked for several minutes, removed one of the plugs and they appear dry. I would expect fuel on them.
I've never dealt with EFI, so I really don't know what to check there to see if it is working or not. I'm an electronic technician so I feel comfortable if I know what I'm checking for.
I appreciate any help I can get.
03-07-2009, 08:28 PM
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Welcome to the site!
Do you hear the fuel pumps engage when you roll the ignition key to On? Should be about a 2 second prime, then they will shut off until you roll the motor.
I mention pumps - the '89s had a low pressure pump in the tank, and a high pressure pump inside the driver-side frame rail about underneath where you put your feet in the floorboard.
When you checked the fuel, was this before or after the filter? Thinking you could have a problem either with a clogged filter, or a clogged pickup screen in the tank.
There's a test port on the fuel rail - it looks a lot like a tire valve. After the fuel pump primes the system before a start - you might want to check this for pressure. If you have a gauge - should get on the order of 30psi, give or take. Either way, watch out - if it's pressurized, it's going to spray all over if you aren't ready for it.
You can check for spark the old-fashioned way - pull a plug, or use a known-good one you have around, hook it up to a plug wire, ground it to the block, and roll the motor. The spark should be towards a bluish color - if it's yellow - may not have enough oomph to fire under compression - perhaps a coil problem, but - one thing at a time.
Suggest to validate fuel flow to the rail, then go from there. Good luck, and keep us posted.
Do you hear the fuel pumps engage when you roll the ignition key to On? Should be about a 2 second prime, then they will shut off until you roll the motor.
I mention pumps - the '89s had a low pressure pump in the tank, and a high pressure pump inside the driver-side frame rail about underneath where you put your feet in the floorboard.
When you checked the fuel, was this before or after the filter? Thinking you could have a problem either with a clogged filter, or a clogged pickup screen in the tank.
There's a test port on the fuel rail - it looks a lot like a tire valve. After the fuel pump primes the system before a start - you might want to check this for pressure. If you have a gauge - should get on the order of 30psi, give or take. Either way, watch out - if it's pressurized, it's going to spray all over if you aren't ready for it.
You can check for spark the old-fashioned way - pull a plug, or use a known-good one you have around, hook it up to a plug wire, ground it to the block, and roll the motor. The spark should be towards a bluish color - if it's yellow - may not have enough oomph to fire under compression - perhaps a coil problem, but - one thing at a time.
Suggest to validate fuel flow to the rail, then go from there. Good luck, and keep us posted.
03-14-2009, 07:06 PM
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Thanks for the advice wde, I really appreciate it. I didn't have a gauge, but I check the fuel AFTER the filter again and it appears to be pumping with a lot of pressure.
The spark looked to be too orange, took the coil to AutoZone and they checked it with a meter and it appeard the resistance was too high on the secondary, so I bought a new one. I installed it, and the truck started right up. It idled strong, I rev'ed then let it idle some more. After idling for two minutes, it started missing like it was running out of gas then finally died and it won't start again.
I disconnect the fuel line before and after the filter and there is no fule pumping anymore. I disconnected before the fuel pump and nothings pumping there either, but I'm sure if it is supposed to. I have fuel in both tanks and switching between them has no affect. I've seen talk of that inertia switch, so I put my meter on it and I have connectivity, with zero ohms of resistance, which I assume it's supposed to have.
Any ideas what to do next? Thanks in advance.
The spark looked to be too orange, took the coil to AutoZone and they checked it with a meter and it appeard the resistance was too high on the secondary, so I bought a new one. I installed it, and the truck started right up. It idled strong, I rev'ed then let it idle some more. After idling for two minutes, it started missing like it was running out of gas then finally died and it won't start again.
I disconnect the fuel line before and after the filter and there is no fule pumping anymore. I disconnected before the fuel pump and nothings pumping there either, but I'm sure if it is supposed to. I have fuel in both tanks and switching between them has no affect. I've seen talk of that inertia switch, so I put my meter on it and I have connectivity, with zero ohms of resistance, which I assume it's supposed to have.
Any ideas what to do next? Thanks in advance.
