[Brando0023]

Have a 21 Zforce 950 sport. Will occasionally start for a few seconds and thats all. Seems like there is a fuel pressure issue that is building to much pressure. Tested fuel pump pressure and it is good. Cleaned the injectors. CHecked the crank case breather hose and all clear. The plugs are getting soaked. It also cranks very slow at times and dont want to crank at all other times. Battery is brand new. Replaced plugs anlso Any suggestions?

[NMKawierider]

When you say the plugs are soaked, is it with fuel or oil? And is it both plugs? Now..it's a new battery but.. is it fully charged? You tested the fuel pressure. What was it?

If the plugs are soaked with fuel, that's a sign that the injector(s) are leaking or stuck open...and if enough fuel gets in it can slightly hydro-lock causing slow cranking..of course so can a depleted battery and if..if the system voltage falls below the threshold of about 11.9..ish volts while cranking, the coils won't charge enough to cause a spark under compression when the field collapses. Also, as the kill switches are not water proof and can get water inside and corrode some but not all the contacts, check it.   

[Brando0023]

Battery is new and yes I changed it. Fuel pump pressure was 45psi. Could be a possible injector issue but they are not Stuck open. I have a motion pro injector cleaner tool and
Cleaned them so they aren%u2019t stuck open and have a good spray also. It%u2019s getting good spark also however the battery voltage does drop to about 10.5 while cranking which I thought was somewhat normal with a good battery. It drops to this even with my snap on jump box on it. Plugs are soaked with fuel and it%u2019s on both cylinders but the front cylinder is wetter than the rear if I pull the plugs out and crank it over it%u2019s blowing fuel out of the spark plug holes, and I disconnected the fuel pump so it doesn%u2019t keep pushing fuel in. Once I blow all the fuel out of the cylinders it seems like it wants to run for a few seconds longer, but then it eventually dies, so it%u2019s kind of flooding itself out too in a way.

[NMKawierider]

Perplexing to say the least. The fuel has to be coming through the injectors...and they are controlled by the ECM..which gets it's signal from the CPS aka engine speed sensor. There has been reports of internal debris being tossed up between the sensor tip and the rotor. Usually that stops the signal to the ECM but with the right material it might cause it to send multiple signals to the ECM causing to pulse multiple times per revolution. Pull it and take a look. Also make sure the engine rotates easily. If its hard to turn over the starter will pull more amps and that drops available CCAs and voltage. Not many with start with under 11.5 volts and 10.5 while cranking isn't normal. 11.9-12.3 would be closer to normal. And you are 100% sure it's fuel on the plugs and in the cylinders and not coolant...right?   

[Brando0023]

Yes it’s fuel on the plugs. Will check the CPS. This issue kind of started out of know where. Was driving down the road and it just shut off and hadn’t ran since. Did check for spark at that time and it was getting intermittent spark. Replaced the stator and haven’t had that issue since now it just starts every once in awhile but then immediately dies

[Brando0023]

CPS looks fine. Nothing on it. Did not test it. Ive noticed if i let the fuel pump cycle a few times before trying to start it, it will run for a few seconds. DOesnt do it every time either. I also noticed when trying to crank it for a few the fuel pump also stops priming itself. THen after awhile it will again.  Re tested the fuel pump pressure and it will prime at 45psi but trickles down to 40 if you let it sit a min. WHen cranking it, it also drops to 40. Not sure if that is normal or not.

[NMKawierider]

All normal sounds like fuel related. Probably check that off the list.Still need to test the TPS though.

[Brando0023]

All sounds like normal as in the fuel pump sounds likes its good? What else could be causing a fuel issue? How do you test the TPS?

[NMKawierider]

All sounds like normal as in the fuel pump sounds likes its good? What else could be causing a fuel issue? How do you test the TPS?

The very first thing you do is get the service manual. It will have all the test procedures and specs. And...you are in luck cause I just happen to have one and will PM you a download link. Not sure what years it covers but it's for a Z Force 950.

[Brando0023]

If the TPS was out of spec wouldn’t it throw and engine code? I’m not getting any codes off scanner

[NMKawierider]

If no MIL light on dash then no code. If the ECM is still getting data and voltage from the unit within spec, then it won't throw a code. What scanner are you using?

[Brando0023]

Snap on Verus scanner