erratic rpm and speedo gauges

[Formula Z]

this morning i washed my car and while doing so i popped the hood and blasted the dusty engine. about an hour later i left to hit up a couple car shows. on my way the rpm and speedo needles started bouncing erraticly (sp) and seemed like the car would miss. i mashed the gas a couple times thinking i probably got something wet that i shouldnt have and thats what was causing problems. it started doing it again and dropped it into neutral and revved it up causing a massive backfire in which the friend behind me said he seen fire come out my tailpipes. few miles down the road the check engine light came on. i pulled over and scanned it and had 3 codes. two were o2 sensor codes which i get occassionally and the other was a maf low voltage code i think. cleared the codes and continued on my way. it did it a couple more times but then got it home. it sat for a couple hours then the wife and i took it to get some ice cream and it did it again when i first started it but never again. any ideas???

[1BADAIR]

head grounds loose?

[Formula Z]

possible maybe?? never had this issue til today after taking a water hose to it. but i do power wash the engine bay a couple times every summer and have never had any issues. i guess once it cools down ill pop the hood and see if i can find anything

[farmington]

Never been a fan of hosing down an engine bay, especially with all of the computers and sensors in there. With older cars it was OK if you stayed away from the distributor and alternator.

[1BADAIR]

everything underhood should have sealed connectors/modules

the head grounds are also used for the cluster

[Formula Z]

yeah but just the rpm and speedo were acting up and misfiring? will have to drive again tomorrow and see if it continues

[Formula Z]

still doing it today... wtf?

[my1994z28]

I would try cleaning the MAF sensor with some MAF SENSOR cleaner and the o2 sensor connectors with some electrical connector cleaner,wouldnt hurt to use some di-electric grease on the plugs..then try dis-connecting the battery for a few hrs or if you have access clear the codes out.

[1BADAIR]

Grounds

[Formula Z]

looks like i need an alternator.... any suggestions where? also what am i looking at spending roughly?

[OIF1VET]

That sucks dude. I officially hate cars..

[1BADAIR]

Put a truck unit in it

[Formula Z]

like what? and why? if u dont mind my asking

[1BADAIR]

kg3 99-03 truck alt is 145 amps
with lower tstats, and stuff the fans run more. the higher amp alt helps
the rear bracket wont fit though. lqk sells them for like $40

[mcalus]

What Larry is explaining.

http://www.ls1tech.com/forums/genera...-failures.html