Hello, i have a 87 trans am with 87 350 style heads.I did a HSR, just cant seem to get it running rt.I get a surge at idle, then once it warms up it goes away.I did everything u can think of to find a vac leak.. there isnt any.I had a chip made for it.When i did a ecm scan the car seem to be alil lean.I guess this might be the problem? Has anyone had this type of problem when install the HSR.Im tryin to find out what problem you guys have had in the install...I dont have the adjustable reg maybe i should get one?
thanks guys

 

being lean is the problem... u need to get it retuned for the HSR........

 

Did it do this before the chip? Did it get worse or better after the chip? What was done in the chip?

Whats your base timing set at? Whats the fuel pressure

Try verifying timing and setting it to 6-8 deg base with EST disconnected, then clean IAC out and reset it.

HSR shouldnt change fueling that much at idle on a L98

 

i swapped my 87 350TPI for a 383 HSR... you guys forget that the 86-89 yrs had a cold start injector... swapping to the HSR basically deletes the cold start injector which pumps more fuel into the intake when the engine is cold on startup. deleting the injector causes a lean condition upon startup. when you delete the cold start injector you have to use a newer 89-92 prom bin as a base which has the cold start already deleted and they use the other 8 injectors to pump more fuel upon cold startup (replacing the extra fuel added by the cold start injector).

running lean only on startup? car uses more fuel when cold so my guess is something in the tune, depending on your combo, injector size, cam/heads/ engine displacement/HP figure... your injectors may not be adequate or your fuel pressure is too low. Id say if you were burning your own chips that u could check the fuel startup tables/ cold start enrich tables and tweak it. where was the custom chip from? can u verify they tuned it correctly? for a non cold start injector and calculated the injector sizes for the size your running? as well as base timing?

If you dont have a adjustable regulator then u should get one ASAP! ull need it to adjust fuel pressure depending on your injector to HP ratio. It just so happens i have an UNUSED brand new HSR adjustable regulator that i have from when i purchased the adjustable fuel rail kit for my HSR. Id sell it to u for 50$ and 5-10$ shipping (depending where u are) the same regulator from summit is 100$ plus the 12$ handling fee.

 

Chip set for the injectors? Stock or aftermarket?

 

sorry guys i was with out internet up to last week.my engine and injectors are all factory stock...except for the HRS. The chip i have was made to delete the 9th injector cold start to work with the HSR.It seem to be lean across the board.It ping alil at full throttle,thats about all the info i can give cause its ur base 350 with a HSR intake.

 

 

when I had one it was always leaking under the upper.. sometimes I could barely find the leaks but the blower would make quick work of the gaskets