My 1999 Oldsmobile Bravada runs rough when it rains and between speeds of 70 to 80?

(2012-02-02 15:15:06)

1. yung gotti Says: When it rains my Bravada tends to run rough.It runs rough between speeds 70 and 80 all the time.I have replaced my wires,plugs,cap and rotor and not to mention i replaced the ignition coil.It used to not start when it rained so i replaced my rotor and it worked fine for awhile,but still had the rough performance between 70 and 80.Now when it rains it runs funny again,but starts.I have no idea whats wrong with it.

2. Robert M Says: How old is fuel filter??? When the FILTER gets clogged, it affects fuel availablility at HIGHER vehicel speeds. REPLACE fuel filter. You WATED your money on the replacement plug wires and wasted MORE money if you used the standard AC Delco spark plugs. Your REAL probelm is a dirty IDLE AIR CONTORL valve, whchi is ATTACHED to your throttle body. It is a BEEAR to get to on these cars. If you are VERY lucky, you will NOT have to remopve the IAC for cleaning. Buy a cn of SEA FOAM spray WITH THE NOZZLE. REMOVE your air intake snorkel and FISH AROUND for the small passageways reveled when the THROTTLE BODY is fully opened. IT will take TWO people to do this. One to hold the THROTTLE open (with the accelerator pedal. and the OTHER to spary the cleaner through the IAC portals. Use a GOOD flashlight, it is HARD to see it. You KNOW you have it if you see a wiring harness attached to it. THe nozzle with the CLEANER ahould penetrate the openings and GARBAGE like sludge and flaky carbon should FOAM Itself out of there. Use GUMOUT as a follow up cleaner. The IAC controls and fine tunes your AIR/FUEL mixture from computer signals begun with information from your O2 sensor(s). Once TOTALLY cleaned up to SHOWROOM pie eating CLEAN, your engine will regain it's lost powe4r and improve preforamnce on HIGHWAY. Once this job is DONE, remove the DELCO plugs and install a set of BOSCH IRIDIUM or DENSO iridium spark plugs. These will ENHANCE your performance, increase fuel mileage and protect your converter from premature failure. They fire fuel CHEMICALLY as well as just sparking the fuel. More power is made with EACH piston stroke!!! Switch over to MOBIL ONE 0W-30 synthetic oil and STAY away totally from regular cheap wax based engine oils that MAKE sludge and RUIN engine sensors. Longer engine life will ensue. CHange oil ONCE a year, that's ALL!! Your start-ups will only require a light tap of the KEY with NO hesitaion or wearing out of STARTER motor after these special plugs are installed. HOPEFULLY, the QUALITY of your NEW cap and rotor are as good or BETTER than the factory units. I use BORG WARNER ones, because they hae BRASS terminals in them instead of ALUMINUM! Better connections. The KEY to everything is a CLEAN throttle body and clean IAC valve!! YOU'LL SEE!!!!