MorganM Posted May 19, 2004 Share Posted May 19, 2004 My '88 GL SPFI is running kinda crappy. Archemitis has been helping me try and figure it out but we are still at a loss on some funny issues. The idle tends to drop and come back or raise and fall. ALL my lights (interior and exterior) dim and surge in time with the engine. Dash idiot lights flash on and off (again in time with the engine running like crap) The Volts guage bounces and reads about 15-16 VDC. I hear the fuel pump at idle slow down and speed up. These symtoms persist till about 2500 RPMs where I cant tell if stuff is just surging and fading so quickly it all runs together or if it is truely running better at higher RPMs. I think it's still present at higher RPMs because the volts meter is still bouncing away! I instantly thought it was an electrical issue. Specificly the alternator which I have swaped another one on. Same problem persisted. Archemitis noticed my grounding system sucked a whole lot so we put all new FAT grounds in. Helped it idle a little more solid but the funny flickering and surging persists. I'm really at a loss here! Only electrical thing I've messed with since this could have started was installing a CB radio. I hardwired it to the lighter. Appropriated its power wire and ground for the CB. The issue is present with the CB off. Is there some stupid sensor loose or a little ground buried deep we missed? Help! Link to comment Share on other sites More sharing options...
Cougar Posted May 19, 2004 Share Posted May 19, 2004 Check the wire connection between the alternator and the positive battery post to see if there is a bad connection somewhere. Using a voltmeter to measure the voltage between the two points is a good way also. You shouldn't have more than 0.25 volts if the connection is good. Check the ground connection to the battery also. Another check to do is on the fusible links which are located in the small plastic box mounted on the coolant reservoir. You may have a loose connection there. Link to comment Share on other sites More sharing options...
MorganM Posted May 19, 2004 Author Share Posted May 19, 2004 Check the wire connection between the alternator and the positive battery post to see if there is a bad connection somewhere. Using a voltmeter to measure the voltage between the two points is a good way also. You shouldn't have more than 0.25 volts if the connection is good. Check the ground connection to the battery also. Another check to do is on the fusible links which are located in the small plastic box mounted on the coolant reservoir. You may have a loose connection there. Grounds are good to go. Redid all of the ones we could see. Didnt fix it I can put a volts meter on that wire but are you talkinga bout the wire that goes on with a nut or the 2 terminal plug? I'll check out the fusible links also. Link to comment Share on other sites More sharing options...
Cougar Posted May 19, 2004 Share Posted May 19, 2004 Sorry I wasn't clear about the wire, there is more than one. The wire that I refer to is the main output wire (the big one, since it carries a lot of current) that is tied to the post with a nut backing it. This wire will tie to the battery. There may be a fusible link in series with it if I remember correctly. Link to comment Share on other sites More sharing options...
nkx Posted May 20, 2004 Share Posted May 20, 2004 i had a poor idle last summer, turns out, a vacuum line was disconnected. got it hooked back up, and everything worked out fine Link to comment Share on other sites More sharing options...
MorganM Posted May 23, 2004 Author Share Posted May 23, 2004 Tried all the suggestions above. Still not solved Spose I'll try another alternator. I really cant think of anything else it could be! It IS possible I have 2 bunk alternators. One was an OEM unit with who knows how many miles on it and the other was from a junkyard. Any other bright ideas? Link to comment Share on other sites More sharing options...
bushbasher Posted May 23, 2004 Share Posted May 23, 2004 when the voltage reg went on my buddies celica the symptoms were very similiar. Link to comment Share on other sites More sharing options...
MorganM Posted May 23, 2004 Author Share Posted May 23, 2004 when the voltage reg went on my buddies celica the symptoms were very similiar. That's what I initially thought. So I swaped alternators. It's a pretty common failure tho and both could have bad regulators. I should just go get another one Thx Link to comment Share on other sites More sharing options...
canajun2eh Posted May 23, 2004 Share Posted May 23, 2004 There are several heavy black wires that attach to various parts of the engine and to different places in the engine bay. These wires also feed into the engine bay wiring harness. They're all black. These are your "ground" wires. You should unbolt each ground wire from its attachment point and clean the connector and the attachment point so that they're nice and shiny. Clean each screw too. Re-attach each wire and make the screw nice and tight. If this doesn't fix your problem, make a new "ground" wire from a couple of pieces of #10 wire and suitable connectors, and connect both pieces between the engine (anyplace on the engine will do) and the car's body (anyplace). Good luck! Link to comment Share on other sites More sharing options...
nutt7 Posted May 24, 2004 Share Posted May 24, 2004 I recently had some similar issues (no surging though) but poor lighting when the cooling fans turned on or the ac was on and no memory for my dash trip meter. I replaced the big alt. wire as stated above with an 8 gauge wire and I soldered an additional 8 gauge wire from the battery to the fusible links...it helped a little, the memory works, windows go up faster, not as much dimming (but some) I hope this helps. Link to comment Share on other sites More sharing options...
archemitis Posted May 24, 2004 Share Posted May 24, 2004 all of his grounds are good, now. we replaced them and added a few extras. im bettin on that big red power wire to the battery is loose. or corroded. and if the plug to the back of the alternator is worn out horribly, maybe thats it. Link to comment Share on other sites More sharing options...
MorganM Posted May 24, 2004 Author Share Posted May 24, 2004 all of his grounds are good, now. we replaced them and added a few extras. im bettin on that big red power wire to the battery is loose. or corroded. and if the plug to the back of the alternator is worn out horribly, maybe thats it. That red cable is clamped down good now. Checked the plug back there; its fine really. Dude at work here today said could be a bad battery. I have ran this one dry a few times. It hardly holds a charge anymore. Maybe time for a new battery adn alternator? Link to comment Share on other sites More sharing options...
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