Fuel Pump Won’t Operate After Completing Head Gasket Replacement (1 Viewer)

[azxr400]

I just completed a head gasket replacement on my 1997 80 Series Land Cruiser. The engine turns over, but won’t start. The truck was running before I started this project and has 220,000 miles. I did the head gasket R&R as preventative maintenance, and took the cylinder head in to my machine shop for surfacing and a valve job. Also re-sealed the oil pans and timing chain cover.

I’m getting spark, but no fuel in the fuel rail. I pulled the fuel return line off the fuel pressure regulator, had someone turn the ignition to the On position - no fuel.

Used a stethoscope to listen if the fuel pump under the rear seats would come on after the ignition was turned to the On position - no sound.

The EFI relay under the hood does come on with an audible click when the ignition is turned to the On position. Both the EFI 15A and IGN 7.5A fuses in the box under the hood are good.

During the head gasket replacement project, I disconnected the main engine harness from the ECM behind the glove box and pulled the harness through the hole in the firewall into the engine bay. Everything was reconnected when I reassembled everything.

I’ve not yet pulled the access cover to the fuel pump to test it, nor have I tested the fuel pump relay.

Does anyone have any ideas as to what the issue may be with fuel pump not operating and suggestions on how how I can resolve it?

-Paul

 

[Tools R Us]

With the key turned to run, is the CEL on?

 

[60wag]

fuel pump doesn't run until engine is cranking, unlike most other fuel injection systems.

 

[azxr400]

With the key turned to run, is the CEL on?

Yes, the check engine light does illuminate when the key is turned to the On position.

I unplugged all the connectors from the ECM and reconnected them, making sure that they seated correctly. I was able to start the engine, but it idles roughly at around 200 rpm and stalls. It won’t sustain running.

I tried rotating the distributor to see if it would smooth out the idle, but no luck.

 

[azxr400]

Yes, the check engine light does illuminate when the key is turned to the On position.

I unplugged all the connectors from the ECM and reconnected them, making sure that they seated correctly. I was able to start the engine, but it idles roughly at around 200 rpm and stalls. It won’t sustain running.

I tried rotating the distributor to see if it would smooth out the idle, but no luck.

I’m also getting a PO340 Camshaft Position Sensor fault code.

 

[ajax1]

Did you time the cams and distributor correctly

 

[2fpower]

MAF plugged in?

 

[2fpower]

Also, check firing order on spark plugs.

 

[baggar11]

Got all the battery connectors on like the fusible links?

 

[azxr400]

Thanks for all your responses.

Yes, the MAF is plugged plugged in, the plug wires are in the correct firing order, the cams and distributor were timed correctly (I pulled the valve cover, and checked the cam timing marks/dots with respect to the timing mark on the harmonic balancer to the 0 mark on the timing chain cover, and removed the distributor and reinstalled it according to the FSM).

On Monday afternoon I started the engine again and it still idles/runs rough. Difficult for the engine to start. Stepped on the accelerator pedal to keep the engine running. With the accelerator floored, the engine will only reach 800 rpm.

I haven't replaced the fusible links, but they are relatively inexpensive, and it would probably be a good idea to replace them anyway as preventative maintenance.

The FSM troubleshooting pages do detail the procedure of checking the camshaft position sensor on the top of the distributor for the P0340 fault code by measuring the resistance between the terminals on the camshaft position sensor. My question to anyone familiar with this process: Do I measure the resistance between Terminal 1 and Terminals 2, 3 and 4, or do I measure the resistance between Terminals 2, 3, and 4?

Anyhow, I'm feeling really low about all the troubles that I'm experiencing with the truck, especially since I've started this project at the beginning of December. I appreciate everyone's suggestions. Like my friends are telling me, "It's probably something simple."

-Paul

 

[BILT4ME]

@Malleus Any ideas?

Any troubleshooting diagrams?

 

[Malleus]

Well, there's a lot there. As to the limited rpm, have you checked to see that the throttle plate is actually moving open? Off hand, I can't think of what keeps this engine from reaching high rpm if there's fuel, air and fire.

My first thought on the fuel problem (if that's what it is) would be to check the fuel pressure regulator. The vacuum line may not be connected properly, on one end or the other.

You could pull the fuel hose off and check the fuel delivery volume. This is from the '96 manual, but the procedure's the same:

 

[BILT4ME]

Well, there's a lot there. As to the limited rpm, have you checked to see that the throttle plate is actually moving open? Off hand, I can't think of what keeps this engine from reaching high rpm if there's fuel, air and fire.

My first thought on the fuel problem (if that's what it is) would be to check the fuel pressure regulator. The vacuum line may not be connected properly, on one end or the other.

You could pull the fuel hose off and check the fuel delivery volume. This is from the '96 manual, but the procedure's the same:
View attachment 1638903

TPS?

 

[Malleus]

maybe, but he says he isn't getting fuel and the throttle isn't responding. The throttle position sensor is an ECU input, I think. I have to check that.

 

[thabruiser]

SO it sounds like you are getting fuel now? (according to post #10). If you have fuel and fire, even though you just had the head done, check compression. Actually, especially because you just had head/valve work done. If you are sure your timing is good (mechanical and ignition), and you are getting sufficient fuel, that would be the next place I'd look. Suck, squeeze, bang, blow.

 

[azxr400]

Yes, I'm getting fuel now. I'll check to see if the throttle plate is opening and do a compression check and let you know what I find.

Thanks for suggestions, I appreciate them and I'll keep you posted.

-Paul