brownmound

Heres my problem. Mound starts up and idles fine. Cruises around fine some of the time, but sometimes, and often lately, it experiences a sudden loss of all power. Seems to happen often in the 2k-3k rpm range. I can get give it gas when it does this and get zero throttle response. Then it will drop down to about 1000-1500 rpm and kick in again, but it stumbles and runs poorly, giving little or no power at all, when it hits the 2k-3k rpm range. It sometimes does it above. Usually I just let it fall to 1000 rpm and mash on the gas and try to get it past 3k rpm and then rev the **** out of it. Today it did this the entire way to work.

I haven't looked into the problem yet. Fuel filter and sparks are recent. Seems to me like it might be some sort of distributor/timing/ignition problem. Any ideas where to start?

Right on.

ratboy

iTrader: (1)

Im sure someone smarter will answer but im going to guess you're losing your leading ignition (either ignitor loose/going bad or loose/bad plug wires). When I blew my leading ignitor it still ran, but ran real rough and no throttle response. Pull your leading plug wires and see if you shock the hell out of yourself next time it happens. Good news is mine got me to and from work on only trailing ignition....

good luck --ERik

LongDuck

Ratboy may be onto something - if it were trailing ignitor or coil, you probably wouldn't notice the loss of power.

The only thing that I might suggest is that you have an intermittent short in the wiring harness going to one of your fuel injectors. On my 84SE a few summers ago, I had almost identical symptoms to what you describe, heretofore called 'running-on-one-rotor' syndrome. Literally, this feels like the car has 1/2 the power that it usually would have, and you can't get it to rev to any speed at all without a LOT of pedal pressure - this is because the second rotor is just vacuuming the suction along, providing no fuel for burning.

Test this by leaving the engine at idle when it's occurring and lift the hood. Grab onto the wiring harness that's exposed right behind the water pump outlet and give it a gentle tug one direction or the other. In my case, the car would immediately spin up and idle smoothly when I pulled the harness forward. After taking off the UIM, I found an intermittent connection to the leading fuel injector. New Borg-Warner pigtails from Autozone ($7 each) and it fixed the problem to date.

Aside from that, have a close look at your TPS and with the engine off, push on the plunger back and forth about 10 times really fast - sometimes this can free up some corrosion or grit that's giving the TPS an odd reading.

Have a look there and reply back,

Oh,yeah - one more thing; "revving the **** out of it" won't help, it only causes other problems that you'll have to fix in frustration...

fishbulb95

^^
I agree with it not being the trailing, because mine just died... lost the tach, and the fuel pump. So i jumped the fuel pump relay, and am only running on leading... (i barely notice a power loss)


if you don't have the money to fix the ignitor i'd switch the trailing and leading, and jump the fuel pump relay so you're only running on leading.

**IS it possible to use the trailing ignitor for the leading or are they two completely different animals?**

Edit: mines an 85 GSL 12A

LongDuck

Both Leading and Trailing ignitors are J-109's and identical - they can be swapped at will. HTH,

nosferatu595

Good diagnostics, guys. I'll add 1 more less common cause:

I've seen gslses that have bad AFMs do this. The meter can be cleaned CAREFULLY!! after dissasembly and reinstalled with silicone. The meter may have an oxidation on the contact or board, or has worn the etching from the board in the common use position (2k TO 3K is normal puttering speed of the engine in city driving).

But try the injector short check above and the ignitor check first . Those are much less work and I agree that they are the most probable cause. Thought I would throw in the AFM just in case the others don't pan out.

When was your last cap, rotor, wire change? These cars often burn through tune up parts in 12,000 mi or less.

Good Luck!

nosferatu595

Fishbulb95:

Do you need an igniter? I have plenty laying around. I'll ship you one for the cost of postage. PM or email me if you need it.