Time to get marsha (2930) back up and running for Dragoncon! Fuel/mixture issue maybe

[nullset]

I'm trying to get 2930 back and in good running condition again. Since I rebuilt it, it's never really been good at revving properly.

It backfires into the intake a good bit. Is this a sign that the mixture is off?

Other issues:

- I think the binnacle has a bad ground. I suspect it's the frame ground in the front, but I'm not sure. The fans run.
- The otterstat is jumpered. When I was testing it, it would get pretty hot and the fans weren't coming on. I wonder if this is a bad otterstat (is that the right name? It's on the driver side of the car, in one of the coolant pipes, with two wires coming out. Shorting it forces the fans on).

Does anyone know how this part should behave in some way that I can test? Or should I just go ahead and replace it? Could a bad ground somewhere stop it from functioning?

That's all I can think of for now.

It has fresh gas, and the injectors and fuel filter were all brand new a year ago, so I'm pretty sure they're okay.

I've got a dwell meter. Will the otterstat affect how or when it goes into closed loop? Is the idle RPM important when setting the mixture with a dwell meter?

--buddy

[Bitsyncmaster]

I've got a dwell meter. Will the otterstat affect how or when it goes into closed loop? Is the idle RPM important when setting the mixture with a dwell meter?

--buddy

Setting the mixture will not change with the otterstat. Idle RPM should not have much if any affect on setting the mixture unless your so low an RPM that the O2 sensor is to cold. You should do the mixture adjust on a warmed up engine.

[nullset]

It idles amazingly well. It's revving it that starts to cause problems.

I've also got a fuel injection pressure tester, so if I can't find anything wrong with the mixture setting, I may look into a fuel issue next. I could also possibly try jumpering the RPM relay.

--buddy

[WelmoedJ]

I'm trying to get 2930 back and in good running condition again. Since I rebuilt it, it's never really been good at revving properly.

It backfires into the intake a good bit. Is this a sign that the mixture is off?
Replied to by Dave M.



Other issues:

- I think the binnacle has a bad ground. I suspect it's the frame ground in the front, but I'm not sure. The fans run.
You should check the ground wire of the inertia switch. If that ground is bad, make a new from there directly to one of the screws on the gear selector mount (Dave M's solution which worked well for me in getting a stable instruments ground as well).


- The otterstat is jumpered. When I was testing it, it would get pretty hot and the fans weren't coming on. I wonder if this is a bad otterstat (is that the right name? It's on the driver side of the car, in one of the coolant pipes, with two wires coming out. Shorting it forces the fans on).

Does anyone know how this part should behave in some way that I can test? Or should I just go ahead and replace it? Could a bad ground somewhere stop it from functioning?
The Otterstat can die in open or closed state (remark from Dave S). I had 3 Otterstats die on my in one year. I replaced it by an electronic Otterstat (from the UK) an never had a failing Otterstat again. A plus of the electronic version is that the temp can be adjusted to accomodate local temps turning the fans on sooner or later.

[Soundkillr]

It idles amazingly well. It's revving it that starts to cause problems.

I've also got a fuel injection pressure tester, so if I can't find anything wrong with the mixture setting, I may look into a fuel issue next. I could also possibly try jumpering the RPM relay.

--buddy

Please check and make sure the warm up regulator has no vacuum when the engine is hot. If it has vacuum it will spit and sputter when you give it gas, but will idle great. It just loads up on fuel. If it has vacuum your thermo vacuum switch is bad.

[nullset]

Please check and make sure the warm up regulator has no vacuum when the engine is hot. If it has vacuum it will spit and sputter when you give it gas, but will idle great. It just loads up on fuel. If it has vacuum your thermo vacuum switch is bad.

It sputters when it's cold too and it's off idle.

I'll check it though.

--buddy

[nullset]

An update!

The problem was that the warm up regulator was not in it's proper place. I've put it back where it's supposed to be (it wasn't on the engine block. oops), and adjusted the mixture with a dwell meter.

I also dropped the transmission drain pan and put in a new not-leaky gasket. Thursday I wash it and reattach the props and she's ready for the parade!

Oh, I changed the oil too. It'd been around 10 miles since the last oil change, but it was over a year ago!

--buddy

[Dangermouse]

Don't forget the grille :fancy:

[nullset]

Don't forget the grille :fancy:

Heh. Already installed!