The new life of the formula fastback

[GTRS Fiero]

The positive lead rested against the oil filter?

It could have been worse.

[NoMad]

The positive lead rested against the oil filter?

It could have been worse.

That exactly. All the 14+ hour days between work, the commute, and trying to get the car ready sure have caught up. But ya, could have been way worse. Now to get back on the road for another of those long days.

[Raydar]

FWIW, when I moved my battery to the front, I installed a knife switch disconnect in the negative cable. I have an Optima battery with both sets of posts. The switch is clamped to the top post, and the ground cable attaches to the other side of the switch. Advance Auto is where I got mine.

BTW... my ground cable runs to the bolt that holds the brake booster to the front bulkhead. I also have two grounds on the engine. One from a bellhousing bolt/stud to the left hinge box, and one from the rear head to the shock tower/dogbone bracket.
I did not "home run" the ground cable. My 2009 Challenger had the battery in the trunk. The ground was connected to the body of the car. Worked fine. 

[GTRS Fiero]

There has been a lot of discussion about the ground cable.  The prrvailing theory seems to be that, although the through-the-body ground can work, a home run ground is best.  That having been stated, everything other than the engine and computer use actual grounds.  In the Fiero, there seem to be a lot of ground issues.

My belief is that ground issues develop over time.

[NoMad]

I went with a home run ground. Also in 0/1. Am adding a bunch of grounds throughout as well to be extra certain.

Battery tested okay. Down more than it should be for its age but I think all the excess heat is likely the cause of that.

Got a 1.7kw gear reduction starter and it weighs nothing compared to the factory. It is the one for the L67 and has the lifetime warranty so it should be worth the money. Went ahead and bought the fancy heat reflective blanket for it as well to try and preserve it a bit more. Also planning to run the hit lead to it as another 0/1 since I have extra left over and the terminals.

ScottB hooked me up with the spare frunk tub and Charlie was kind enough to bring it out to the neighborhood for me so I could grab it tonight and not have to make an extra trip.

So Raydar, why the knife switch? For storage? Security? Ease of disconnect for working on it?

[NoMad]

Well the car runs and drives again. Full oil change and a seafoam intake and upper cylinder cleaning as well. The real story though is the timing! Was 8 degrees off! I am going to guess that was a large portion of my MPG issue right there. A reset to 10° made the motor much happier and peppier. Test drive went well as I ran into Athens and filled up the car on a full tank of premium (usually I run base grade). All seemed wonderful but now the surging is back once I got it good and hot. Still haven't sorted the temp gauge so I am not sure the actual temp range it starts yet.

The car does drive a little bit nicer with the battery out front and the new starter (1.7kw for a 3.8SC) really kicks it over nice.

Oil looked good and was right at the 3000 mile mark. Early for my regular changes but it had to happen.

I am certainly out for RFTH with the surging happening. Omce the outside temp comes back down again I will go ahead and start looking at the temp gauge so I can get some accuracy on when it starts missing and if it is temp related. The miss starts when under load/accelerating.

[Fierofool]

Missing under load is usually secondary ignition components.  It could also be ignition coil or timing.  My brother's 86 had a surging problem and it turned out to be the ignition coil.  Fieros like OEM style coils over the aftermarket MSD's, Accel's, etc.  They also like the factory number spark plugs. 

[GTRS Fiero]

I agree.  The ICM could also be the issue.

[GTRS Fiero]

Has the o2 sensor been replaced?

[NoMad]

Looking at some other people with similar issues it might be the fuel injectors or wiring to them. Will look into it tomorrow.

[Fierofool]

We replaced all the injectors with new ones of like kind that were in the engine.  They weren't stock Fiero injectors, but something the original builder had installed.  The car ran great while we had it at Northlake.  The only thing we had problems with afterward was that the fuel pump went out again so we replaced it along with the sender. 

Scott pulled out for a test drive and surprised himself when he broke traction as he started down the street. 

[GTRS Fiero]

With the nastiness in the filter, the injectors could be fouled.

[NoMad]

I have put a lot of miles on the car since buying it so it really could be anything. Going to do some methodical trouble shooting today and see what I can find.

[NoMad]

So today was a wash....

Ran around to get the stuff I needed together and got into testing. I started at the coil, distributor, and ICM. Pick-up. Cpil and actual coil both checked good.

I took the ICM to advanced near me and asked them to test it. At first the kid said they can't. I insisted that they should be able to so he begrudgingly asked his manager. Yup, they can and he would teach them. They finally came back saying it failed all but one test. Great, problem solved! They didn't have one but a call to O'Reilly's confirmed they had two grades in stock. I drove over and figured I would have them test the ICM as well just to be sure. Their machine is down. Well I look over both units and opt to spend a little more and get the US made Standard Switch product.

Get home and install it all with only a little difficulty. Check and reset the timing. Seems okay. Test drive looks great till 45 minutes in when I turn around happy and go to get up to speed again. Surging is back under load and when mashing the pedal suddenly. Almost like an old round slide carb flooding the cylinder with too much fuel from too rapid a twist of the grip.

So back home and back into the garage. Guess tomorrow is back at it for the morning then the truck to work.

[GTRS Fiero]

I wonder if there is a bad ground.  Does the new coil test OK?