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Wedge TR7 ok at low RPMs

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mgb4tim

mgb4tim

Jedi Trainee
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I changed the starter on my 81 FI DHC...finally. So now it fires right up, but starts to bog now at higher RPM's, like over 2,500 RPM.

The idle was always an issue, but I got info on where the set screw is, and planned on doing that next. If I try to give it gas, it starts to backfire a bit. It doesn't want to die, but just seems like it running into a rev limiter.

I checked all my plug wires, I check that long wire that goes from the distributor to the AC/Delco "coil". Tomorrow I'll try to adjust the idle to see if it runs smoothly at about 1100 RPM. If it was fuel starvation, would it backfire?

I thought it might have been because I hadn't tightened the big cable stud on the started, but it's tight, and the voltage meter reads fine, too.

It ran "fine" before the starter change, but it had one heck of a time with that old cranky starter. What gives?
 
Have you checked the timing since you put in the new starter? Maybe the new starter pulled the timing chain out of time.
 
If I try to give it gas, it starts to backfire a bit. It doesn't want to die, but just seems like it running into a rev limiter.

<span style="color: #990000">That's how mine ran until it was finally
diagnosed as a failed ignition condenser can.
A real fast swap to test what might be your issue.

best regards,

d</span>
 
Since you don't have the condenser that Dale referenced, it may be the internal module to that distributor. Moss lists it as #072-465 at $39.95. Just a wild guess though.
 
mgb4tim said:
failed ignition condenser can? What and where is it?

I have the AC/Delco coil. Can I replace it with a normal high energy type of coil, like the Flame Thrower or the Crane FireBall?
Click to expand...

Pull the module out of the coil assembly and take it to your local Autozone and they'll test it for free. You can also get the module just about anywhere...they were used in millions of Chevy pickups in the early-mid 80s. The part number is Delco D-1906 (I think...). When reinstalling it, use a good layer of thermal grease, as they are very suseptible to heat issues.

I'd also suggest you take a look at the plugs, plug wires, and distributor cap and rotor...

As far as the coil goes, you shuold be able to convert it to something else, but I don't know how to go about it. If it is the coil, they are scarce (but PM me if process of elimination says coil and I might be able to hook you up).
 
ObiRichKanobi said:
...they were used in millions of Chevy pickups in the early-mid 80s.
Click to expand...
That would make it a standard GM HEI, right? If so, then you should be able to use any HEI-compatible coil. Some of the Crane Fireball coils are compatible, others aren't. Ditto the Pertronix coils, I believe.
 
Mine acted kinda like that after I got the head back on. I had put the plug wires in the cap backwards so it was only running on two cylinders. Check the simple stuff first, the things we most likely overlook. Dale
 
Are there additional symptoms? Like loss of power, coolant temperature higher than normal, etc?
 
It ran fine before, I was just needing to adjust the idle up a little. I knew the timing was a little off, because I didn't think it revved as high as it should.

I tried playing a bit with the distributor today, but it didn't make a difference. All the plug and cap wires are fine. I tried to check all the FI hoses, the dizzy advance hose (that was my second thought).

I wish I could comment on the temp, but I can't drive it with such low revs, if it's the timing, it'll overheat fast, no?

I'll have to crawl under there with a light and have another good look around. and take the module to get tested.
 
I had the pin on the jack shaft break once on my 81 once (when it had the fi engine). I pulled the distributor and retimed it and drove on. Every time I used the starter it would slip once more out of time, I think just the initial shock of the chain moving from a stop. The jack shaft also drives the water pump.

I have an extra timing chain and a modified jack shaft if you decide that's what you need. I had two heavier pins put in to replace the stock (single) pin. I don't think that you need a shear pin at that sprocket to protect the valve train so a small pin seems pointless to me.

I don't need the jack shaft or timing chain so I would only need postage to ship to you. It's easy to verify the timing, the rotor is supposed to point to a specific place on the head when at tdc.
 
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