CJM Fuel Hat and 340lph Pump ISSUE
 

Does anyone just have the CJM Fuel Hat and the aeromotive 340 Pump installed?, not the return!

I finished my install the yesterday, threw some codes, fuel temp and fuel level sensor high output.
Double checked my pin out and reinstalled, reset the codes and the ECU and the codes haven't come back.

THE PROBLEM:
I was able to get the car to start RANDOMLY over very spaced out intervals, like a completely cold start and the car fired right up... idled a little rich due to the jump from a 255 to a 340 (Jon Parham is adjusting once I figure this out)

Literally let the car idle for 10 minutes so I could datalog a idle, and then turn the car off and tried to crank it back up and nothing, it will spin like crazy but just wont fire up?????

Any help would be greatly appreciated

I've done this but with a DW200 and also rewired the fuel pump at the same time. I have not had any issue thus far but yours does sound like either a loose connection or ground issue.

If you leave the silver cover plate off can you hear the pump prime when you try to start the car?

It may be a ground issue indeed but how do I go about tracking it down? And yes I can hear the pump prime every time I put the car in the "ON" position

While this would involve you pulling the fuel assembly out the tank again, measure the resistance from the pump connector to chassis ground. Also measure the resistance between the pump connector positive and the positive wire on the chassis harness.

When you installed the pump in the basket.....might the fuel filter have been pinched or something?

The fuel strainer? The filter is the actual basket the pump is housed in (paper filter) I cut that off and added an external aero motive filter downstream. The strainer is seated properly though because I took it out again to check lol!

But I will remove once again and check resistance. You say to check the pumps ground to the body? And check the pumps 12v to the 12v of the fuel hat connector?

Definitely sounds like your connector. My stock unit was loose and had to tighten everything down. The starter would just crank, but nothing would happen.

Yeah sorry I meant the strainer. Well if that's not pinched off it's bound to be a short between the pump and the factory harness wires.

The fuel pumps connector ground wire should have no resistance against a chassis ground. Same goes for the fuel pump connector positive wire and the oem wiring harness pump supply wire.

If you get a paper clip and straighten it out to push down the back of the new plug (in the pin your measuring at the time) you had to crimp the wires for that will let you know what you're dealing with across all the connections

good luck!

Just ideas, but the majority say check the wiring so I would go with that first. Defintely let us know what you find!


Sounds to me like the cylinders are just flooding and possibly getting the spark plugs wet. I think this because you mentioned it will start in large intervals. If it is priming then the pump should be working.
I did a twin turbo kit on my first Z and after about a month the car died while driving, and was narrowed down to the fuel pump. I had someone replace the pump because I was not in the area and had no issues after that. When i did have my issue, the pump was NOT priming which i do not know the exact cause except maybe a connector got fuel in it and over time, failed. When I connected the pump to the battery of the car, it worked great ruling out a bad pump and bad wiring, so something with the actual connectors was messed up. Now because It would not prime and the pump worked when connected to the battery, that's where i concluded it was probably the connectors and once replaced everything worked.

Yours is priming so that's good, it's getting a signal and works. It could be the connectors so I am not ruling that out, however, i feel that if the connection was not good, the pump would not operate, die while in idle, or just wouldn't start back up at all. You MAY need to get a fuel return ( stuck with my walbro 255 when i had the turbo Z) system.

I got this off the Aeroomotive site but i didnt read to far into it, im at work and i think its a different pump (stealth): The Aeromotive Stealth 340 Pump is typically not listed as compatible with OEM returnless fuel systems, for good reason. #6 https://www.aeromotiveinc.com/tech-h...th-fuel-pumps/

They were talking about fords though........ :roflpuke2::

Again, just ideas but the majority says wiring and check it so i would go with that especially checking the connectors. Good luck and definitely let us know what you find!

Sounds like a plan, I’ll rip the pump back out tomorrow and go over all the connectors, may even pop them out and solder them all

So explain this.... my trying to start this thing for an hour, with a battery charger hooked to it, and nothing just spins like crazy

BUT THEN, I unplug the fuel pump connector behind the seat and BAM!!! She fires up within 2 tries!! But why??

:confused:

So it's starting without the fuel pump? I think there are some typos in your last post and this is what you were trying to say. If thats the case.....pure ******* magic.

Sounds like you could have a ground issue like what people said before? Not much of an electrician but id say you have it narrowed down to the connectors. Has the car thrown those codes again or are they still gone from when you cleared them?

Still kind of weird because if the fuel pump was out then nothing was sending fuel and with no fuel in the cylinders it should not fire off unless there was fuel from trying to start it earlier..... IDK, sound like gremlins.

Gremlins indeed.

Sorry about the typos, that is what I get for typing all of that on my phone late last night. I have correct them lol.

And yes I will be checking the connectors today.

These issues cannot be related to the billet top hat since it merely a replacement mount for the fuel pump module. Based on your DTCs, it sounds like there has been some incorrect wiring performed, or the vehicle was turned on with the connector disconnected at some point.

If the fuel pump is turning on as it should, but the car doesnt start/run correctly, assuming it originally did start/run correctly before installing the 340 pump, your problem is most likely the idle pressure fix was skipped when installing the pump... and its just too rich due to excessive pressure.

http://host.cj-motorsports.com/pdf/3...ump%20Tech.pdf

Section 9 covers what is almost definitely the source of your problem based on your descriptions so far.

Because the engine was flooded. When you disconnect the pump and then crank the engine, fuel pressure will drop and momentarily pass through an acceptable range to run the engine before it falls too low and the engine stalls.

I drilled the venturi out per the instruction. I used a 0.085" drill bit I believe. So what could be the problem?

I have a fuelport coming in this week with a gauge so I can check pressure.

That might be a bit small. Also, since you are returnless, you will probably have to modify the factory regulator as well. It has a very small outlet.

This is something we have never done. Seeing as that we are big into return systems, we havent tried putting that large of a pump on an otherwise stock fuel system.

You will see for sure once you have your fuel pressure gauge and someone to watch it while you crank. For now you should try putting your old fuel pump back in just so you know everything else was installed correctly.