No power, shuddering under load

[Shoxr]

Let me be a little bit more specific when the engine is running the alternator is charging we need a good ground from the engine to the body or else we run into problem that's why a good ground from engine to body helps to support the electronics that you're running a bigger coil Morris Park radio all of these things play into it so you have to have a good wire from the engine to body I usually run a wire from the tail of the transmission mount hoodie transmission mount on the body the stud that have the nut that's usually a good spot try it and see what happens

[my8950]

Let me be a little bit more specific when the engine is running the alternator is charging we need a good ground from the engine to the body or else we run into problem that's why a good ground from engine to body helps to support the electronics that you're running a bigger coil Morris Park radio all of these things play into it so you have to have a good wire from the engine to body I usually run a wire from the tail of the transmission mount hoodie transmission mount on the body the stud that have the nut that's usually a good spot try it and see what happens

What does this say? Morris Park? Transmission mount hoodie?

[zxr250cc]

Hi all,

I used a Scotch Brite pad and cleaned every removable wire connection for ground or hot leads under the hood to improve overall results and had the benefit of the under hood light starting to work again after refusing to work previously. The other connections all benefited from the lower resistance clean connections as well, I am sure. The washer motor also worked better. Free time plus Scotch Brite pad = good electrical health for the stuff under the hood.

Cheers

[thesameguy]

It's important to remember that electricity travels in a circle, so whatever the + is, the - has gotta match. The two biggest electrical doodads are the starter (hundreds of amps) and the alternator (tens of amps). You need a single big ground from battery to engine for the starter to work, and that connection will also provide (easily) sufficient ground for the alternator. You also need to provide electricity to chassis systems, like the lights and fans... anything not connected to the motor. Thus, you need a ground from battery to chassis that is capable of supporting the load. More grounds are not, generally speaking, better. The chassis itself is made of metal and unless you need to run something electrical that only attached by rubber, the single ground is sufficient. The exception is for sensitive electronics, where small fractions of a volt could result in different behavior. For these items, a home-run ground to the battery (or main ground point) or a local ground may be warranted. Often, cars will have a few major ground points sprinkled around to keep wiring harnesses orderly and provide these local grounds. The other "exception" is grounds that might dissipate static and control electrolysis, which you'll typically see in areas where air or coolant moves - the intake manifold is an example of this.

When I redid my battery cables, I ran 2ga from battery to starter, 2ga from battery to block, 6ga from battery to alternator, and 6ga from battery to firewall. I have within .2v of alternator voltage everywhere in the car. I left the aforementioned straps from body to intake manifold, though I'm not 100% sure that's necessary with the dry lower. IDK, so I left it.

More grounds is not better. The right number (typically two) of good grounds is the key. Cables can fail at the ends, but they can also fail in the middle. I replaced my alternator cable because corrosion from the end had traveled quite far up the cable... Probably people kept cleaning the terminal, overlooking the fact that between cleanings corrosion had crept up the cable. I kept cutting it back, the wire was still garbage. Eventually, I replaced the whole thing. My personal approach, on any car, is replace the battery cables from top to bottom every 10-20 years.

[Buffalobill]

Got to screw around a little more. O2 sensor is reading 12v when warmed up. No one local has it in stock, got a standard products on order from rock auto....

[Buffalobill]

Lol, nevermind, I was testing it wrong....

[Buffalobill]

Finally got it home to my shop.

Thanks again for the help on this thread, and especially to the guy that sold me a sunpro code scanner.

Ran like crap all the way home, plugged it into the scanner.

Codes retrieved are: 14,54,56,58,63,66,81,82,83,84

14 indicates the pip

54,56,58 indicates a bad vam

63 indicates that I need to twist a little more voltage into the tps, which I replaced over the winter, and set it to .95, iirc.

81,82,83,84 all seems to be related to the egr delete.

What's the pip, how do I go about fixing it?

Vam, is there a trusted source for turbo ford guys, or is everyone rolling the dice with rock auto parts?

[john keefe]

The PIP is the stator inside the distributor. Get a new, or NOS Motorcraft one. You'll have to punch out the pin to remove the distributor gear in order to pull the shaft out. Nice to have a real hydraulic press to pull/push the gear off and on the shaft, but you can do it without one if you have the patience. Probably not necessary, but I always marked the gear and shaft holes on one side so it goes back on the same way, to avoid any slight variations in rotor timing. Not sure of any troubleshooting procedures, or "fixes" that can cure a PIP signal, but combine that with choppy/mixed signals from the VAM, and erroneous air-fuel ratios without the anticipated EGR gases as anticipated by the ECM, and it would certainly run like crap.

[Buffalobill]

Lol, oh, it runs like crap!

Are the parts store remanufactured distributors and vams sketchy?

[john keefe]

Are the parts store remanufactured distributors and vams sketchy?

Here Ya' go... ideas galore on the subject LOL! : viewtopic.php?f=19&t=38784

Personally, I'd ask Jeff (Blugg @ Merkur Midwest) or Mike ( Merkur Depot)what they have used or new in stock first.

[andyofcolumbusmerkur]

Are the parts store remanufactured distributors and vams sketchy?

Personally, I'd ask Jeff (Blugg @ Merkur Midwest) or Mike ( Merkur Depot)what they have used or new in stock first.

x2 for sure

[merkurdriver]

54,56,58 indicates a bad vam

I would definitely put a known good VAM in first, see what happens, and pull codes again.

[Buffalobill]

Got a rebuilt distributor from rock auto, after installing it, it runs 70% better!

It still isn't right but now it's just doggy, and I can drive it without making a scene. Before it was undrivable.

Waiting on a blue streak electronics rebuilt vam.

Going to double check timing and tps voltage as well tonight.

What is the timing supposed to be set at?

[Ed Lijewski]

Timing info is on the emissions sheet in the plastic underhood envelope.

YMMV

[JimG]

Rock Auto is great for my other rides, but for the Merkur I prefer to support those who work hard to have parts and knowledge necessary to keep our cars on the road. Rapido, Merkur Midwest, Merkur Depot, MC2racing and Stinger. In some cases you may pay more but I've found that the support can be worth it.