P700 700 Starting issue

[mk36345]

Guys,
Sorry, don't post here much but I've got a '14 700-4 driving me insane.

Problem started as a hard start (sometimes would start, then had to grind on starter a while) now no start. Have checked the following:
1. replaced spark plug with iridium plug
2. replaced coil
3. replaced injector
4. compression good
5. valves adjusted with plenty of travel (cam replaced a year ago or so)
6. Replaced fuel filter sock on pump
7. Checked/cleaned the exhaust
6. Checked/cleaned air filter
7. replaced battery, good voltage when starting
8. No maintenance indicators or error codes visible

We have gotten the machine to start with starting fluid, once the engine is running it's fine, plenty of power, great throttle response with no bogs. I haven't checked fuel pressure yet, didn't want to cut into the fuel line to tap out for a gauge yet, but plenty of volume when the initial pressure cycle of the pump with key on is checked. I have checked spark, coil is firing the plug good. The one thing I have found is that using a noid light, the injector only fires once when you initially turn the key, then doesn't fire again. I have noticed that occasionally, the injector will fire when the key is released from the start position. can't find any issues with the wiring that indicate damage there. I'm beginning to lean toward a bad ECM, just wondering if anyone has seen something like this previously. Is there some connection in the keyswitch that could create this as well?

thanks in advance
Mike

 

[Admin]

 

[mk36345]

Guys,
Sorry, don't post here much but I've got a '14 700-4 driving me insane.

Problem started as a hard start (sometimes would start, then had to grind on starter a while) now no start. Have checked the following:
1. replaced spark plug with iridium plug
2. replaced coil
3. replaced injector
4. compression good
5. valves adjusted with plenty of travel (cam replaced a year ago or so)
6. Replaced fuel filter sock on pump
7. Checked/cleaned the exhaust
6. Checked/cleaned air filter
7. replaced battery, good voltage when starting
8. No maintenance indicators or error codes visible

We have gotten the machine to start with starting fluid, once the engine is running it's fine, plenty of power, great throttle response with no bogs. I haven't checked fuel pressure yet, didn't want to cut into the fuel line to tap out for a gauge yet, but plenty of volume when the initial pressure cycle of the pump with key on is checked. I have checked spark, coil is firing the plug good. The one thing I have found is that using a noid light, the injector only fires once when you initially turn the key, then doesn't fire again. I have noticed that occasionally, the injector will fire when the key is released from the start position. can't find any issues with the wiring that indicate damage there. I'm beginning to lean toward a bad ECM, just wondering if anyone has seen something like this previously. Is there some connection in the keyswitch that could create this as well?

thanks in advance
Mike

Guys,
To update:
9. Fuel pressure good (50..PSI) maintains 47 to 48 psi on the line after pump shuts off
10. IAC Motor functioning as specified in the Service Manual
11. Throttle body cleaned nothing obstructed
12. Installed new FICM
13. No stored codes, No MIL light

This is the most frustrating issue I've ever encountered. We don't have any local support from either the Dealers or Local shops, their only answer is "bring it in, we may be able to get to it in a couple of months". I someone knows a current or former Honda Tech that would be willing to share some information I would really appreciate it. About to give up and tell my friend he's out of luck.

 

[Remington]

You haven't checked compression or said you have adjusted the valves yet!

We know its a 14’ P7 but how many miles? Pics would be appreciated as well!
Oh and welcome to the Forum

 

[DG Rider]

Guys,
To update:
9. Fuel pressure good (50..PSI) maintains 47 to 48 psi on the line after pump shuts off
10. IAC Motor functioning as specified in the Service Manual
11. Throttle body cleaned nothing obstructed
12. Installed new FICM
13. No stored codes, No MIL light

This is the most frustrating issue I've ever encountered. We don't have any local support from either the Dealers or Local shops, their only answer is "bring it in, we may be able to get to it in a couple of months". I someone knows a current or former Honda Tech that would be willing to share some information I would really appreciate it. About to give up and tell my friend he's out of luck.

What's a FICM? Is the injector still not firing?

 

[mk36345]

What's a FICM? Is the injector still not firing?

You haven't checked compression or said you have adjusted the valves yet!

We know its a 14’ P7 but how many miles? Pics would be appreciated as well!
Oh and welcome to the Forum

You haven't checked compression or said you have adjusted the valves yet!

We know its a 14’ P7 but how many miles? Pics would be appreciated as well!
Oh and welcome to the Forum

1st post #'s 4 & 5 we're on the compression and valve adj.....

Injector fires one time when when using the key to start

 

[mk36345]

1st post #'s 4 & 5 we're on the compression and valve adj.....

Injector fires one time when when using the key to start

My mistake....Honda refers to it a the PGM-FI, not a fuel injection control module (FICM)

 

[Hondasxs]

Have you tired running it on ether spray into the TB manually?

I'm sorry.
Your already over my head in regards to suggestions.

Sent from my SM-G996U using Tapatalk

 

[Remington]

1st post #'s 4 & 5 we're on the compression and valve adj.....

Injector fires one time when when using the key to start

Sorry, I missed that. You got so many things going on….

so u replaced a cam a year or so ago, did u do the whole low end at the time since u had it apart or just the cam?
again, how many miles on the rig?

 

[mk36345]

Sorry, I missed that. You got so many things going on….

so u replaced a cam a year or so ago, did u do the whole low end at the time since u had it apart or just the cam?
again, how many miles on the rig?

We did the cam/lifter cups first, exhaust lobe was completely worn round. Then we did a top end (new piston/rings w/bore) about 6 months later (blow by was horrible; smoking and oil consumption). Mechanically everything appears to be great. Like I mentioned, if you get it started, it idles and performs perfectly. Just will not start without adding a snort of starting fluid or gas

 

[Remington]

We did the cam/lifter cups first, exhaust lobe was completely worn round. Then we did a top end (new piston/rings w/bore) about 6 months later (blow by was horrible; smoking and oil consumption).

🤔

 

[Remington]

if you get it started, it idles and performs perfectly. Just will not start without adding a snort of starting fluid or gas

Since u changed everything, sounds to me like a CPU issue, like it needs to be reflashed or some signal issue in the start sequence. Some things will not throw you a code.

Again, how many miles on the rig itself?
we havent got to #POIDH part yet

 

[DG Rider]

1st post #'s 4 & 5 we're on the compression and valve adj.....

Injector fires one time when when using the key to start

What about the plug? Does it have a normal looking spark pattern?

 

[mk36345]

Since u changed everything, sounds to me like a CPU issue, like it needs to be reflashed or some signal issue in the start sequence. Some things will not throw you a code.

Again, how many miles on the rig itself?
we havent got to #POIDH part yet

Total mileage is around 5k, about 900 since the top end was done.

Really want pics of the disaster that it is now???? Covers and push pins litter the shop around it right now

 

[Remington]

Really want pics of the disaster that it is now???? Covers and push pins litter the shop around it right now

Sure! Its like train wreck, you have to look! 😂

No, of cores not, know body wants to see that! When it was all together and perdy lookin! 🤦‍♂️

 

[mk36345]

What about the plug? Does it have a normal looking spark pattern?

Missed the reply regarding spark, yep plug is firing with what appears to be regularity. That's what's funny, the plug is firing but the injector only fires once

 

[DG Rider]

Missed the reply regarding spark, yep plug is firing with what appears to be regularity. That's what's funny, the plug is firing but the injector only fires once

Yep...that is interesting. Rules out a crank sensor.
So...I know certain trouble codes will cause the ecu to shut down injector pulse. Any flashing check engine lights?

Also, some vehicles (like GM) have a "clear flood" mode if the throttle is at or near wfo throttle. The injectors don't fire. Don't know if Honda does that, but Maybe a bad tps showing the throttle wide open would do this?

Let's find out what @HondaTech thinks?

 

[mk36345]

Yep...that is interesting. Rules out a crank sensor.
So...I know certain trouble codes will cause the ecu to shut down injector pulse. Any flashing check engine lights?

Also, some vehicles (like GM) have a "clear flood" mode if the throttle is at or near wfo throttle. The injectors don't fire. Don't know if Honda does that, but Maybe a bad tps showing the throttle wide open would do this?

Let's find out what @HondaTech thinks?

No MIL indications, either at key on or with a jumper installed on the DTC plug.

Thought about the TPS, but it didn't really make sense that the engine would idle and run properly once it's running.
I'm familiar with the open or closed loop for a automotive system that set's the operating conditions for start through engine warm-up. I know from talking to the folks at Dynojet that the P1K's use that as well in the programming. I just can't find anything about that for the P7 either in the service manual or online.

 

[DRZRon1]

sounds totally maddening…..

when u crank and no start, injector only fires once, and then a shot of ether and it starts and then the injector majically starts working? engine speeding up making injector fire?

it was fine before rebuild, the mechanical work seems top notch, so it
almost seems like some sensor\connector - nothing else changed, possibly short battery leads together, I think this discharges caps in the brain and re check all connections taken apart for the engine work?



Btw - what was the compression?

 

[mk36345]

sounds totally maddening…..

when u crank and no start, injector only fires once, and then a shot of ether and it starts and then the injector majically starts working? engine speeding up making injector fire?

it was fine before rebuild, the mechanical work seems top notch, so it
almost seems like some sensor\connector - nothing else changed, possibly short battery leads together, I think this discharges caps in the brain and re check all connections taken apart for the engine work?



Btw - what was the compression?

Compression was 135 psi

 

[Mopower58]

Is it possible that the wiring harness connectors might have moisture in them? I had a 350 Kawasaki Enduro motorcycle that got submerged in water years ago and would only start periodically and it ended up being moisture in a connector. You might unplug all pertinent connectors,make sure they're moisture free, apply liberal amounts of dielectric grease and reconnect. Looking at a schematic the injector has two wires with one running to the ECM. Possible ECM failure? When you said FICM I had flashbacks to 6.0 Ford diesels, took me a minute to compose myself!