new member need help

[blaylock440]

my 87 gn has me stumped. all the sudden while driving my car starts misfiring
and compleatley fallng on its face. as soon as i start to put my foot into it it starts sputtering. i thought it was fuel related so new pumpwent in no change then got code 34 maf . changed it still same problem checked for vac leaks cant find any changed some lines just to make sure.still no change
can anyone give some advice. can get some boost if i feather the pedal but if i step into it it wont go at all

[Keller]

Can you give us some more info on the car?

- Mileage
- Modifications
- What plugs are being used, and what gap
- Are the coil and module on the car AC Delco, or aftermarket

[blaylock440]

my miles are just over 100,000
all parts are acdelco
plugs are rapid fire acdelco
i think it still has original coil and modual
my dad works for chevy dealer every thing is acdelco
car has no mods all original

[kenmosher]

Some common points of failure:
- MAF
- Fuel pump
- Coil/module

[chas52]

had that same problem about 5 yrs ago.
check the hoses on the intercooler.
make sure they are on tight.
good luck
chas52

[Keller]

A leak anywhere between the turbo and intake would cause a problem.

It is very rare that an original coil and module would last this long. I would definitely suggest those be changed, especially if the coil still has the month/day/year sticker with white print on the top and the TURBO V6 with a No. xxxxxx as well on one end. If its really 22 years old, its time. Even if its half that old, its probably time.

In addition, the Rapidfire plugs may not be an optimal selection for this application. The original R44TS (gapped at .035!) are just fine. In fact, a R43TS would not be a bad choice, as the heat these engines endure due to the turbo makes a bit colder plug a good choice.

[PaCemkr86]

what maf did you use when you swapped it out?? new, used, GM, reman ??

[gusszgs]

Originally Posted by chas52

had that same problem about 5 yrs ago.
check the hoses on the intercooler.
make sure they are on tight.
good luck
chas52

I agree with checking the intercooler hoses. By mistake I left the lower upipe hose loose while working on the car back in the summer. I had almost the identical symptoms.

[blaylock440]

Ok guys i have another gn motor complete. With 60,000 ml that
i have been swaping out parts from. It came out of rear ended car
so i have taken the maf off of it and it is original eq. I changed
the complete braket with map,two relays,and i think its the injector controle on passanger side fender. Its got a new fuel pump and i replaced lots of vacume lines. I didnt think of turbo to intercooler yet but 5000 miles ago i replaced all of the hose connecters with new gm ones.iguess i try that and coils and module. If there are any more suggestions i will try them thx

[Ts86ttype]

I saw that you put in a new fuel pump??? Have you put a fuel pressure guage on to see what the pressure is??? Some times you have to be a parts changer but it is nice to do some diagnostics to get you to the right area. Tom G.