Marxxpress

1983 RX7 GSL fully stock

Problem- erratic ideling occasionally (blub blub blub blub blub) to the point where it will die unless I keep the RPM's high enough using the accelerator pedel. Doesn't happen all the time- seems mainly at the warming up stage before the choke goes in, and later after driving mid to higher RPM runs and then coming to a dead stop. When it drops down to idle, it acts up. Sometimes will seem like it slowly wants to just die down- it will get really faint, and then just die. Drive off- and it runs smooth again. Overall, I have noticed that the idle speed is running lower than it ever has.

I took the advice of a few people on here and replaced the fuel pump and fuel filter. Didn't fix the problem. I also have checked for a vacuum leak after receiveing advice from others- NO LEAK. Replaced spark plugs, cap and rotor and checked for any loose wiring. NEGATIVE. Nothing wrong there.

NOW WHAT!?!??!?!?!


Something I noticed tonight- I don't know if it's related, but hopefully it is and will better assist you in diagnosing my problem. I took it to an AutoZone to test the battery and alternator/charging system. No problems there. I did this because I noticed upon driving home tonight that when I had my lights on in conjunction with my rear defroster (putting a heavy load on it) I noticed the volt meter on the dash was running below 12V. When I rolled the power windows down in addition to all the above things going, it dropped down to about 9-10V and the lights obviously dimmed. In addition to this, tapping the window switches caused the RPM gauge to jump up and down (flicker) but not necessarily cause the RPM's themself (engine) to act as the gauge was representing. Could whatever's going on here be related to why I might have an idling problem?

I talked to a buddy tonight on the phone. He said he has a Honda that acted the same way. Replaced the main relay and it fixed it. Does this car have one- or is that it?? HELP!!!!!!!!!!!! I'm despirate. I'm thinking of dropping it off at the dealer or perhaps selling it. I can't stand seeing my cream puff in this condition!!!

Dan_s_young

iTrader: (1)

^^^ I have the same problem, havent been able to fix it yet... maybe someone will have some good advice =) The only way to get myn to run better was to completely retard the timing which is just wierd...

jays83gsl

You're absolutely sure you don't have a vacuum problem? If you're still online when this gets posted, log onto your AIM and I may be able to help you.

Rotor13B

Did you check for leaks around the manifold and carb? Also, Have you replaced your battery cables? They may seem decent but inside they could be corroded. Check your engine ground strap also.

Dan_s_young

iTrader: (1)

could the problem actually be due to battery cables? My battery cables corroded straight through thats when I started having this problem, I cut the corroded part out and am still using the same cables, maybe this is my problem???

jays83gsl

Well, it can't help, Danno

Siraniko

iTrader: (13)

call Chris @ SPD racing or check in the west forum. if not, feel free to drive it up to me. But, Im in LA. I dont charge much....just a 12-pack of heine.

jays83gsl

Heine? That ****'s the ****.

Siraniko

iTrader: (13)

yeah but no need to drink a case to get buzz. besides, i get no hangover. so I drink even on week nights.

Dan_s_young

iTrader: (1)

ok I was gonna ask... I looked into it before, looking for a vacuum leak but since I removed all my emissions, I don't think this is the problem, I almost think its my lead ignitor...

Siraniko

iTrader: (13)

the easiest way to check is using a timing light. just clamp it and zoom zoom. no light means dead igniter or bad connection.

Hades12

Check for trailing Spark. If Leading spark was gone then it would not run. Trailing will make it run rough.

Dan_s_young

iTrader: (1)

When i was attempting to set my timing I was sometimes getting an irratic spark, and when I lined the light up with the mark on the pulley the car ran like total crap and wanted to fall on its face, then if you chopped on the throttle the car would either stall or hesitate for a few seconds...

Siraniko

iTrader: (13)

is it a rebuilt motor or original?

IanS

iTrader: (4)

"trailing will make it run rough"

Siraniko

iTrader: (13)

it will run even without the leading.

Dan_s_young

iTrader: (1)

original

Aviator 902S

I'm assuming your air filter is also in decent shape. If it were badly clogged it would create an overly-rich condition (especially with the choke pulled) which would cause the idle to "load up" and die.

But the fading electricals point to alternator or battery problems. First, remove the cables and clean the posts, clamps and cable ends. Do not forget to also confirm that the lead from the alternator is clean and in good shape. Re-connect and try again.

Park in a dark garage (or do this at dusk) and with the car idling turn on the headlights, then the defrost, wipers, stereo and other electricals one by one. You should see the volt meter drop to 12-ish, but not lower. (With all accessories off the voltmeter should read at least 13 at idle and at least 13.6 at cruise). The dash lights should not go dimmer. If you blip the throttle and they become brighter there is a problem, possibly the battery not taking a charge, but even more likely the voltage regulator is on the fritz. Only problem is that the voltage regulator on these cars (except for '79 models) is located INSIDE THE ALTERNATOR.

Also, check the battery's specific gravity and fluid levels. Use a hydrometer to check the water/acid level in each cell before filling. A good reading is 1.275 to 1.300 per cell at room temperature. Any lower than say, 1.2 after the car has ran for a while (on a standard day with temps around 60F) without using electrical accessories would mean the battery is not being charged or not taking an adequate charge. Top up any low cells to the split ring, re-charge and then check specific gravity again.

Kentetsu

I think Aviator 902S is on the right track. Only thing I would add is that when you clean up your connections, do the ones on the starter as well. What you've described could be a lack of consistent/sufficient grounding. I would also replace that chopped cable while you are at it, just to be safe.

Also, when running funny does it smell rich?

Good luck with it.....

Marxxpress

I fixed it. Vacuum leak. No problems now. What a great car I have!

james hull

You might have sticky float valves. This would require a carb "tuneup". Rx-7s are prone to this especially if they are not driven regularly. Look into your carb's sight glass areas when the car is idling bad. If the fuel levels vary a lot, or the sight glass(s) are full, then that is more than likely your problem.
Good luck.