stumped

[Yao]

I need to have some idea bounce off you people. The car misses when ever underload badly. Tried new sparkplugs/wires, still does the same, I am gonna look at the coils this weekend. Anymore ideas?

 

Check the injector clips I dealt with a DSM that would miss anytime that I wasn't absolutely babying it. Turned out to be a loose connector.

Also swap in a different, and known good, MAF. Also check that pigtail for broken wires/loose connection.

 

[Terry Posten]

Check your fuel pressure. New fuel pump sock filter, inline fuel filter, make sure the regulator is good and set right.

 

[Nate]

I second that filter sock suggestion. That took me MONTHS to track down.

 

[beaner]

Did you cut the fuel pump assembly to install the pump? I have seen this problem when the new pump is put in just like stock instead of cutting that cone off the assembly and attaching the new pump to the assembly with a hose and clamp.

 

[Yao]

Thanks for the ideas, I didn't get too much time to troubleshoot this weekend, spend time in the emergency room with the kid this weekend. I am ordering fuelab fuel filter, so that would take a week to get here. If anything, I also get this whiny supercharger noise that coincide with engine load??! All belts looks good, but I don't know, crank pulley seperation? exhaust leak? what else would be whiny in the engine bay that coincide with misses...

 

[TRBODSM]

Sounds like a blown turbo or small boost leak. I would check the shaft play on the turbo and do a boost leak test along with the stuff mentioned in the earlier posts

 

[tsiboy]

crack open your ECU and check for damage. If you have a known working spare try swapping it in.

 

[Yao]

Looks like I might of found my problem. I went to replace the fuel filter and found bits and piece of shinny objects in the fuel, upon closer inspection, seems like metal shavings. Could only mean my bosch 044 is eating it self and on top of that, I have the 40micron fuel lab filter in there..... think my injectors might be plugged or damaged? I am gonna pull the pump and fuel injectors tomorrow and see how it looks like... damn injectors are only couple of months old....what could I replace 044 with? isn't there something simliar if not better for intank from walbro?