Need some experienced help.

[KALSC]

Hi all, been fine tuning the turbo project and all has been going rather well with the exception of a few items which aren't directly related to the swap.

I have in issue with my car with which I am at a total loss. I can't get it to start, for the second time. The first time was when I had to take the upper intake manifold off (no brainer) and do some stuff, nothing major. When I zipped it all back up, the car wouldn't start. I farted around with it for two days finally just walking away. I went back out the fourth day after leaving everything sit for a day, and walla, it started. Huh?

Well, I don't know what the deal was and my computer wasn't giving me any codes either. All was well, but then I noticed my fuel injectors we weeping. I ran a check and the car I got them off of had not been taken in for the recall. I tracked down a set of injectors off of a turbo 300zx which has been serviced in the recall, heck these babies still looked new!!! I tested them (resistance, open/close, etc.) and was well. Again I took my upper intake off to install these 'new' injectors, zipped up the engine and CRAP! It wouldn't start again. Same as last time, as the days went by, it would get better and better, meaning it would at least sound like it wanted to start, but to no avail.

I have tested and checked everything (coil, different distributor, different FPR, checked for good spark, check the fuel PSI and flow, checked all the sensor for proper resistance, checked parts of the wiring harness for continuity, etc.) So far, you name it, I have checked it. BUT, everything is becoming such a blur I feel like I am missing something, I must be missing something cause I can't find the problem.

Here's another interesting note, when I turn the car on, my fuel pressure gauge reads 38 or so PSI, right to spec. So I ran a test where you pull the fuse for the fuel pump (same as you would do to depressurized the system) and as I crank the car over, the fuel pressure drops, incrementally down to zero, like it should. So that tells me that my injectors are not only holding pressure but they are also operating and releasing the fuel. Here's the kicker, when I get down to 10 psi and under, the car actually runs, very rough though and then stalls when it runs out of fuel.

I have tried different air flow meters, a different computer, blah, blah, blah. Someone make a suggestion please, I am ready to loose my freakin mind here! ;-)


PS - The blow valve I had shown you before is working great! When the car was running. LOL! Rest asssured, my troubles right now aren't related to the turbo swap directly, there is some other gremlin giving me grief right now.

[Nismo87SE]

This maybe a something stupid but check and see if your fuel lines are reversed. Also I guess check and make sure all the injectors are plugged into the right connectors. That is if nissan did the injector recall. If you know the engine has spark and compression then there is a fuel problem. The only possibitily is that the fuel lines were reversed if the injectors are good and there is fuel flow after the fuel filter.

[KALSC]

Thanks for the suggestions. I am seriously getting my a$$ kicked by Maximus, he's proving his worth in truly being The Great in this case.

The fuel lines are on correctly, I wish it were that easy. If the lines were reversed, then why the last time this happened would it all of a sudden start the next day with no apparent change in anything? Welcome to my screwed up world.

I am totally convined it is a fuel problem. As I descrived in the original post, it seems like there is too much fuel or that the air/fuel mixture isn't being metered or delivered correctly. As the psi drops when the fuel pump is disconnected, under 10 psi to 0 psi, the car actually runs a little until it runs out of fuel (due to pump not acitve).

I checked my chts at it reads 3.4 k-ohms, bang on to what three others I have kicking around here read.

Here's a question, in the injector recall people mention that not only were the injectors replaced but part of the harness as well? What part? Just the injector plugs or what?

Come to think of it, I have had problems with this car ever since I got it, meaning that I just couldn't get it to run right. Maybe I do have a harness issue.

I think what I am going to do is pull the injectors and connect them to test for leakage (AGAIN!!!!!) and for pulse (AGAIN!!!!!) It wants to start, it wants to run, but the air-fuel ratio is just not where it should be. ACK!!!!!

[KALSC]

In everyones opinion, when you see a spark plug fire on our Max's, what do you see? A white or blueish white zap? Cause all I get is an orange zap, which makes me think of a weak ignition system. If the spark is too weak then it may not be able to ignite the richened fuel mixture due to a cold start. Thoughts?

[maximase86]

Originally posted by KALSC
In everyones opinion, when you see a spark plug fire on our Max's, what do you see? A white or blueish white zap? Cause all I get is an orange zap, which makes me think of a weak ignition system. If the spark is too weak then it may not be able to ignite the richened fuel mixture due to a cold start. Thoughts?

I usually see a bluish white zap...as for orange zap, that's different. It could be possible that it could be that...to you have another ignition coil sitting around? Give that a try and see what happens...

S

[KALSC]

Found the problem, well . . . problems.

First off when I had to rework the rocker pedestals and zipped up the top end, the O2 sensor failed momentarily then. But it decided to kick in again and that's why the car started that time.

This time, after I changed my injectors, the O2 sensor decided to fail again and stay gone. In my ignorance, I took it for granted that on the Max's the O2 circuit would be bypassed for the first minute or two at start up allowing it to heat up in order read right. Hence, I never thought to check it. Well, I found out that the O2 circuit on our cars is active right away, hence the three wire lead, the system preheats it so it starts to reference the mixture ratio right away.

Not knowing this happened, I never thought to check the O2 sensor as I thought it was being bypassed. Once I found this out, I pulled it and checked it and sure enough I was getting intermittent readings. Aha!!! Or so I thought. I put in a new O2 sensor, but to no avail.

Talk about frustration. Then I found out that due to the failing O2 sensor, the car is but into an over rich condition, which I knew, but that over rich condition (extremely over rich) fouled my plugs, its called fuel fowling. Basically, the plugs get so drenched in raw fuel that it seeps into the plugs and kind of shorts them out. Sometimes they are recoverable, but mostly not.

Sure enough, I put in a new set of plugs and the baby fired right up.

So, long story short, the failed O2 sensor sent my car into an extreme over rich condition, so rich it couldn't ignite and the raw fuel fowled my newer plugs (1200 kms now). The new plugs combined with the new O2 sensor were the ticket in my case.

I learned two things, three and four wire O2 sensors are active right away and an extreme over rich, non-igniting situation can totally ruin even a new set of plugs.

Maximus lives!!! Time to finish testing the new blow off valve and crank this baby up to 12 psi. Buuuuuuahahahahaha!!!

[Nismo87SE]

Don't forget to check the ECU's A/F ratio alpha in diagnostic mode II. If both LEDs aren't on then you need to recalibrate it.

Originally posted by KALSC
Found the problem, well . . . problems.

So, long story short, the failed O2 sensor sent my car into an extreme over rich condition, so rich it couldn't ignite and the raw fuel fowled my newer plugs (1200 kms now). The new plugs combined with the new O2 sensor were the ticket in my case.

I learned two things, three and four wire O2 sensors are active right away and an extreme over rich, non-igniting situation can totally ruin even a new set of plugs.

Maximus lives!!! Time to finish testing the new blow off valve and crank this baby up to 12 psi. Buuuuuuahahahahaha!!!

[max95q]

Originally posted by Nismo87SE
Don't forget to check the ECU's A/F ratio alpha in diagnostic mode II. If both LEDs aren't on then you need to recalibrate it.

Recalibrating the maf? Like on the 2nd gen forum at Yahoo, right?