98 S10 V6, cold start problem fixed, now rough running ,need diagnosis

[1966 BIG BLOCK]

Heres my Story, a few weeks ago my 98 V6 S10 ,started to have overnight cold start problem, no check engine light, has 74,000 miles never had tune up so >> I replaced fuel filter, plugs, wires , cap & roter, cleaned throttle body & replaced air filter...........now starts right away ,but runs at 90% power & has hesitation , took to mechanic he checked fuel pressur, fuel pump said OK.........but had bad coil he.. replaced coil..& charged me $$ $$$... I drove home, ran a little rough figured the computer had to set itself,eek after 20 miles , still has hesitation & 90 % Power........ very frustrated ....History Note as long as I can recall has had AM radio static consistent with engine RPM.. now now on, thinking i should take to Chevy dealer as thet have tech equipment for correct diagnisis.......... or should i replace ignition modle first ??? dont have the money to keep shelling out, when a mechanic cant correctly figure out .

[muddog321]

GM has the scan tool. Static is usually plug wires. So no codes. Clean the MAF sensor next and see if that helps and look for vac leaks especially if 4wd and all those lines up front.

[1966 BIG BLOCK]

Muddog,I did clean MAF with the MAF cleaner spray, , also installed new plug wires & plugs possibly one of the plugs is defective or i cracked one of them during installation, think its time fro mr goodwrench & his diagnostic tools,Monday Note mechanic hitched up scanner plug number #1 not fireing , its the easyist one to get at ,will advise out come.........

[Chris Stewart]

Is that '66 a rectangular port motor...427/425?

[1966 BIG BLOCK]

Yes L72, Vintage 66 block Cast feb 66.....modified for dependability & tourque, Endlebroc alm heads , MSD pro billet dist & box, comp cam roller tipped rockers, short duration high lift .515 Comp Cam xtreme energy cam.,self imposed redline of 5700 RPM.....no hedders , stock side ex..body completly stock , all new suspension. TRW design composit rear spring, & various vette brake suspension components Tripple black correct colors. Crager SS wheels,all parts updated sitting in basement I have all original components, heads, starter moter, nice power full driver easy for me to work on & figure out unlike my 98 S10 & wifes 03 grand am.

[Chris Stewart]

Wow, that's so cool. Sounds like a real old school stomper.