this will test the best 300 tech on here

[demonZ73]

100% rebuilt engine from top to bottom ............also 100% out of things to try and parts to replace

1. all new gaskets and seals
2. rebored cylinders .020 over w/ oversized pistons
3 shaved heads
4. stage 3 500 cams jmf from import parts pro
5. full stainlees exhuast
6. new pcv valves
7. new and adjusted TPS
8. new MAF
9. new fuel injectors (cleaned fuel rail)
10. new injector connecters
11. new fuel temp. sensor and coolant temp sensor and connecters
12. throttle bodys removed cleaned and even syncronized back together (new gaskets)
13. idle air adjustment assemmbly removed cleaned inspected and put back together (new gaskets)
14. water coolant delete, IAV delete, EGR delete.
15. currently not throwing any codes.
16 have done a power balance test all coils seem to work and get spark.
17. fuel pressure good.
18. PTU sub harness delete
19. timing is correct and (and yes i did count the cogs correctly)
20. CAS seems to be good because car does run
21. good battery
22. new ngk stock spark plugs
23. brand new PTU

now the symptoms are the car will always start, however will not idle and has very bad throttle response, like......will not rev when i press the throttle rapidly, althou will rev when i press it slowly, also the idle air adjustment screw has no affect on the speed or idle of the engine what so ever even when i turn it while running with the iaa plugged in or not. now even after replaceing all those external parts of the motor the symptoms have never changed not even a little, in other words after replacing a part or doing a delete i tried the car and no differance...........it aslways still ran like crap. well now that i think about it i will say this i pulled all coils and they all did get spark. but when i left all them in and then pulled the connecter to the #1 coil it did idle down wich is a good sign that the coil is working, however when i did the other coils from what i remember i do not think they idled down like they were suposed to (this of course was being done with me holding the throttle open to keep it idling)

[Ziggy1621]

Ok, a couple questions. I do not see that the coil packs were replaced right? Neither a new harness, so assuming its the old harness correct? Has the ECU been tuned, or is it stock? And lastly, has there been an upgrade to the air intake, or is it still stock? Has it been cleaned or replaced recently? Just a few questions to get a feel.

[demonZ73]

correct i have not replaced any coil packs however like i said i did test them by removing each one and grounding the spark plug and got spark, when u say harness exactly what harness are you talking about, but yes i have not replaced any harnesses so it would be stock altho just did the sub-harness delete, the ECU has not been tuned by me at all i have had a few friends tell me i have to do work the the ECU however when i talked to kyle puckette from import parts pro because of the cams i put in and he said i should not have to do anything to the ecu, and the air intake from what i can see is bone stock i havant done anything but just changed the MAF, is there anything specific i should check on the the entire air intake system, tonight after replaceing the ptu i ended up reving the motor kinda high the highest i have ever done since iv had the car around 6,000 rpm (6,000 is kinda high for how bad its running) basically just beacuse i was kinda mad lol, althou the exhaust sounds really good the thing just ran like such sh*t and some other noise from the engine i didant really want to hear, im really starting to think it might be something inside the motor i might have messed up i just dont see what tho that could cause this kind of running problems, and sure enough died when i left of the throttle................anymore help is great thanks so much

[nissanfreak12]

What MAF did you put on it? Where did you get it from? Is it the N62?

[J30tChumpCar]

+1 on the MAF, perhaps try another, new does not always mean good.

[Ziggy1621]

Just pointing out the obvious also, I'm guessing you already know this if you are doing this all yourself, but also check the condition of your air filters

[demonZ73]

thanks guys.......the MAF is a used one however its from ashspecz actually in really good shape and was tested on a car before sent to me, im not getting bad MAF symptoms from what i hear happens when one goes bad, however whats weird is that my car will idle when i unplug the MAF and if i plug it in while running......the car dies. and yes i have cleaned the filters ........thanks again if u guys can think of anything els it would be great other than that i think its time to just give up on it and sell it i cant put anymore money into it and iv been saying that for a few months lol

[J30tChumpCar]

I still want to say just because it worked before it was sent in the mail (who knows what happens to stuff in transit) check the car with another MAF.

I recently was witness to a random stupid mistake where the MAF was installed backward, drove several people buggy till it was noticed.

Here's another one, it wasn't a bad sensor I had some deep water go through my MAF, it barely ran for the next 20 minuets with similar symptoms and no codes.
Yes it is normal to stall when plugging and unplugging.

[t.mcginley.jr]

13. idle air adjustment assemmbly removed cleaned inspected and put back together (new gaskets)

By inspected, do you mean you actually tested it or just looked at the inside?

http://home.swipnet.se/e-solutions/IdleTech.html

[demonZ73]

i looked at it and tested it applied voltage and heard the clicks...........does anyone know to post a car for sale on here ?

[spiffy]

Hey man, your symptoms seems to be a lot like mine acted this spring, are you sure your fuel pressure is ok?