EFI problems, no combustion

uscmas412

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Apr 19, 2015
Messages
331
Location
Navarre FL
 
Symptoms:

Cranks/turns over strong every time, but combustion is not occurring. Problem has been traced to a lack of fuel. I’m thinking I’ve got a bad connection somewhere in the EFI system.

What's been done so far:

-This week
No fuel dripping or streaming from fuel pressure regulator return hose at crank.
Fuel pump replaced, original OEM fuel pump checked good after removal

EFI relay, fuses, fuel pump relay and resistor all tested good.

All dashboard lights check good (i.e. CEL appears with keys to ON)
Fuel relay clicks
Good spark at plug #1 and from ignition coil
Ignition coil passes resistance
No CEL and code reader shows no pending codes
NSS pulled, sprayed with electronic cleaner, no visibly chaffed wires and reinstalled
Checked all fuses in cab and engine
MAF connection checked, it's solid and the intake tube is <3 years old


-Within the past year
Battery strong and new as of two months ago
All battery cables/ground straps replaced
Fuel filter replaced w/ OEM
Distributor, wires, plugs, alternator and engine wiring harness replaced a year ago when the engine was rebuilt. New OEM or DENSO


-Possibly related

I've had a loud metal rattling sound and exhaust leak. The rattling was narrowed down to IVO the first catalytic converter, but again, no codes were showing.
Also, while under hard acceleration I would experience a sudden loss of power. Very noticeable. This was on level ground at sea level. After letting off the gas pedal it would accelerate fine again.
 
Last edited:
Joined
Jan 17, 2019
Messages
75
Location
Southwest
I'll start with a caveat: I am a novice at engine troubleshooting. I'd let the gurus chime in before I make WAGs.

That said, engine needs spark, fuel, air, and compression. You say engine was rebuilt so that should eliminate compression. Air: How is the air filter? Fuel: New pump and filter would resolve majority of issues. Maybe check fuel regulator for proper operation. If it was busted, it could prevent fuel pressure from building. Spark: Should be good with new distributor, plugs, and wires.

Timing could be the cause if it was significantly off. That would mean you are sending spark at the wrong time.
 

uscmas412

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Apr 19, 2015
Messages
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Navarre FL
 
Forgot to add another symptom prior to the no start, while under hard acceleration I would experience a sudden loss of power. Very noticeable. This on level ground at sea level.

Let off the gas pedal and it would accelerate fine again.
 

ppc

M Go Blue
Joined
Aug 18, 2003
Messages
3,026
Location
Nashville, TN
 
 
 
Is the CEL illuminated with key turned to "On" before trying to start?

If not the ECM is not getting power. Check the fusible links. Search for other threads with the same "no start" issues. There are hundreds of them all with about 3 causes.
 
Last edited:
Joined
Mar 31, 2013
Messages
59
Location
Dubai,UAE
 
i was facing same issue it cranks but wont start. Problem was wire connector on driver side in hood was loose.
-Check igniter , connector and ground
-Igniter coil
-engine bay driver side check connector

FF6F9F83-627E-45F8-A7C5-66EAB350AFC9.jpeg
 

uscmas412

SILVER Star
Joined
Apr 19, 2015
Messages
331
Location
Navarre FL
 
Is the CEL illuminated with key turned to "On" before trying to start?

If so the ECM is not getting power. Check the fusible links. Search for other threads with the same "no start" issues. There are hundreds of them all with about 3 causes.
Yes, CEL is illuminated. Believe me I’ve probably read the majority of the threads.

I’ll double check all the connections in the engine bay.
 
Joined
Nov 9, 2012
Messages
9,172
Location
Olathe, KS, USA
 
Is the CEL illuminated with key turned to "On" before trying to start?

If NOT the ECM is not getting power. Check the fusible links. Search for other threads with the same "no start" issues. There are hundreds of them all with about 3 causes.
FIFY
Please correct your second sentence. I know you know this, but sometimes typing doesn't work right.
 
Joined
Oct 26, 2019
Messages
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Location
Garden Grove
Every engine need is Air, Fuel, and Spark. First i would do is take Cylinder #1 spark plugs out and check if it got fuel going to the cylinder. Then verify that it got spark by grounding the spark plugs and have someone crank the engine. If it does, spray some starter fluid to the intake and see if it start. If it does, the you have fuel problem. Try to narrow down the problem, rather than jump all over the place
 

uscmas412

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Apr 19, 2015
Messages
331
Location
Navarre FL
 
[QUOTE="azngarage, post: 13116341, member: 161008”] First i would do is take Cylinder #1 spark plugs out and check if it got fuel going to the cylinder. Then verify that it got spark by grounding....
[/QUOTE]

I removed #1 plug and verified spark, I removed ignition line from distributor cap and verified spark and the ignition coil passed resistance test from FSM.

How do I verify fuel going into cylinder with spark plug removed?
 
Joined
Oct 26, 2019
Messages
106
Location
Garden Grove
remove the spark plugs and check to see if there any fuel residue on the spark plugs. Also if you have spark, then spray some carb cleaner into the intake and it should fire up
 

uscmas412

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Apr 19, 2015
Messages
331
Location
Navarre FL
 
I didn’t see any fuel residue when I pulled #1. Just disconnected the return hose from the fuel pressure regulator, tried to crank and no fuel came out.

In fact, it was dry when I disconnected the return line. Not sure if that’s normal.
 

uscmas412

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Apr 19, 2015
Messages
331
Location
Navarre FL
 
I hooked up the old fuel pump to a 9V battery and it turned on. So I think I can safely rule out the fuel pump.
 

uscmas412

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Apr 19, 2015
Messages
331
Location
Navarre FL
 
The FSM does not match what I’m seeing for the Circuit Opening Relay, page EG-162.

The EFI Main relay was swapped with a known working part and it did not help.

DE9B4287-E1D5-4B83-8DD9-4B2AA06CE5C3.jpeg


A43A33FD-3BCE-4425-BEAC-BF349D2A4D40.jpeg
 

uscmas412

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Joined
Apr 19, 2015
Messages
331
Location
Navarre FL
 
I managed to find This post about a circuit opening relay but a little confused by what they determined. I swapped out the bottom most relay in the picture I posted and I still have no fuel coming out of the FPR.
 
Joined
Jan 26, 2010
Messages
390
Location
Clovis, CA
 
 
Forgot to add another symptom prior to the no start, while under hard acceleration I would experience a sudden loss of power. Very noticeable. This on level ground at sea level.

Let off the gas pedal and it would accelerate fine again.
This is interesting.

Has it sat for a while before this no start condition occurred?
 
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