If I rev car full throttle it cuts out for sec until I let up a little then stutters and revs on up idles a little rough to done checked fuel pump fuel filter injectors wires plugs tps maf readjusted rockers does it worse cold when I first crank it but any help will be great thanks car tuned by Solomon 383 306 cam Afr heads one more thing if I rev slow to 2000 then stomp it it revs ok

 

No help from no one????

 

I responded to your PM's

your engine is not stock and if you're absolutely sure that the FPR and fuel pump are good, and injectors are correctly sized for the 383 and flow, then it sounds like ignition.

I'd find a local shop where the guy has also raced or modified cars (sexist I know not thinking a girl would own the shop) and ask him to hook it to the scope.

Yes, you'll pay but it's way better than tossing parts at it. You need information prior to proceeding. Unless you do this day in and day out, sometimes it's wise to pay for experience.

 

Yes put new fpr on bought Bosch 30lb injectors off eBay and I ohm them out to make sure good put new wires and plugs on car checked fuel pump got 255lph walbro with hotwire kit I put copper gaskets on headers and they not sealing great u said that might problem but. It cuts out cold is the o2 sensors even reading then ??? I checked for vac leaks couldn't find none changed intake gaskets to see if I had internal vac leak but didn't I'm lost I just sent MSD opti back to MSD so they can check it out hopefully that's problem and I got new maf tps sensors and ect and map new ICM to

 

were the injectors new or used?

 

Have you checked the temp sensors,(ECT & IAT) for proper operation? These sensors are crucial, especially on a cold engine.

 

Bought injectors off eBay used I no there used but I ohmed them out put a screw driver up to them and listened to hear them clicking they all was clicking good and ohmed out good changed ect changed tps I pulled up DataMaster and dataloged car didn't see nothing real bad but I really don't no to much bout computers I did see something on data log when I stomp it from idle it cuts out for a sec r 2 my knock counts jump up when eng comes back to life after it cuts out I get no spark retard just knock counts don't no why weird its probably false knock if I'm not retarding spark I thought????? Thanks for all tha help keep tha post coming

 

If you get enough knock counts, the spark should retard regardless of whether the knock is real or false.

 

You have to understand the issue you are having is what we call a driveablitly problem. The mechanics that are good at working on these problems get paid very well and most shops only have a few of these guys. To do the job well you need to understand every system in the engine and spend at least 2 years working on this type of issue with support from guys that know what they are doing. Teaching someone how to diagnose a driveablity issue in a thread is like teaching someone how to build a house by writing a paper. I have spent a hour on the phone trying to help a mechanic, he gave up brought me the car and it took me 20 minutes to fix it.

Why do you think the knock sensor is false? Based on what you have said you described a car that is leaning out on acceleration. This would cause the car to hesitate and cause knock signals. With acceleration the computer needs to predict the engines needs. It does this with the throttle position and by vacuum. Throttle position is telling the computers what you want and the vacuum is telling the computer the load on the motor.

By text book you would focus throttle position sensor, the map sensor or the Fuel pressure regulator. This lean condition would show up on your O2 sensors. Work experience says older or dirty O2 sensors react slowly and do not always pick up these short burst of lean. It also says is the sensors and FPR are all working you need to check for a back up cat messing with the vacuum, Air cleaner, collapsing hose to the MAP sensor and about 10 other thing.

 

Do you know what valvetrain components your 383 has? Roller rockers, a gear drive cam, and/or a loud rumbly exhaust can cause engine vibration and activate the knock sensor, retarding the timing, creating a stumble. One fix, if that's the issue, is to use the less sensitive LT4 knock module (in the PCM). As a test to see if that's what's going on, you can unplug the knock sensor on the side of the block, and see if the stumble goes away.