Another "won't start" thread... after several changes. Ideas?

[240z4u]

Well, I made the fatal mistake of making a BUNCH of changes all at once over the last few weeks, now it won't stay running.

I changed;

Intake ManifoldExhaust manifoldinjectorsfrom blow through, to draw through MAF setupThrottle bodyFrom catch can setup back to PCV setupShortened wire harness underhood, lengthened harness for 02 and MAF

Symptoms;

Car fires up, then idles way up and then dies.

I think I found the idling up problem, the IAC was sticking. Not 100% sure on that one. Ill know tomorrow.

One thing I did do, was change the location of the ground wire from chassis to block.

Evan
Modified by 240z4u at 6:54 AM 2/28/2008

[Joe]

what do you mean you changed a ground from the chassis to the block.

explain

[Carl H]

have you rescaled the pfc for the larger injectors?

[240z4u]

Alright guys, sorry for the lack of information. Actually, I probabally posted this prematurely. I need to work on it a bit more to figure out whats wrong.

Since I went back to a draw through setup, I went into datalogit and rescaled the injectors for the 650s and the z32 MAF when I loaded the stock power FC map back in.

I changed my ground from chassis to the alternator (I wasn't paying attention and cut it). I strapped an 8ga ground from the motor mount on the block to the frame rail. I need to check the resistance from the block to the chassis. This seems like part of the problem.

When the car DOES fire up and rev up it runs really smoothly.

Evan

You guys can hold off on any other posts until tonight when I can get a closer look. I was just wondering if anyone had ever had the symptoms like this. I did the swap long enough ago where I should be able to figure it out. Ill be sure to let everyone know if I do.

[240z4u]

Found the problem, I did not get the fuel rail tight enough against the intake manifold which caused vac. leaks.

Thanks guys - Evan

[s13_240_rb20]

Found the problem, I did not get the fuel rail tight enough against the intake manifold which caused vac. leaks.

Thanks guys - Evan

watching your fuel gauge, you are saying that the vac leaks caused a loss of fuel pressure??? I am asking because mine is losing fuel pressure when I rev, so I am waiting on a vac/boost gauge so I can monitor mine...

--TJ

[240z4u]

No, fuel pressure was fine. It was a vac. leak from the injector Orings.

Sounds like you have a dirty fuel filter or a dying pump.

Evan

[s13_240_rb20]

No, fuel pressure was fine. It was a vac. leak from the injector Orings.

Sounds like you have a dirty fuel filter or a dying pump.

Evan

I know that my pump was suggested before, but here is what I have done today. I took my pump out and put a 13.75v power source to it, while cycling gas with injector cleaner. The following 4 videos are in order and I'll make notations to anything special...

pump starts out fine when turned on..http://s268.photobucket.com/al...9.flv

pump slows down greatly but will still build pressure to my fingertiphttp://s268.photobucket.com/al...2.flv

pump gains significant power when removed from gas (kinda expected, since air is lighter than gas???)http://s268.photobucket.com/al...3.flv

pump only trickles after that....http://s268.photobucket.com/al...4.flv

sounds like I need a new pump eh?? Should I go with another Bosch?? Walbro?? I've tried em both...which one is more reliable and can get the job "done"??

[240z4u]

My warlbo (sp?) is 3 years old with no problems.

I think your pump is shot, that does NOT look right. That flow is way too weak.

I have not done it on this car, but when I had an aeromotive and .5" fuel line it was like a damn firehose.

Did you run the gas tank dry at any point? That can cause cavitation (pump sucking air) and damage it over time.

Evan

[s13_240_rb20]

never ran dry...i know i've seen my fuel shoot out of the engine bay when I was testing for fuel flow early last year...lol That's why this trickle looks like such an obvious problem...

--TJ

[240z4u]

Sounds like you found your problem then! don't forget to get a new fuel sock too. Do some searching, there was a post awhile back about the fuel socks that I vaguely remember and you might find useful.

Evan

BTW, I dont remember any details but it was something fitment related.