Wedge TR7 Fuel Injection/Charging system help.

[mgb4tim]

Have been putting some time into the TR7 the past week to get her running, just in time for winter. Got the water pump replaced and installed a new the cold-start injector - huge starting difference.

But it's acting up. When it wants to start, it cranks over 2-3 times and fires. Runs for a while, then dies. Read tonight's story below.

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I park it with the charger coz I've been cranking it alot, trying to coax it to start.

I go out in the AM, starts right up. After work, starts right up. If it stalls while running after a while, I crank and I get poop.

Tonight, I start it up, back and forth the driveway I go any number of times. Through the grass, around the garage, up the street to my other driveway. Back down, back up.

This time, I go down into the grass, start back around the garage and...poop!

Crank it, and it seems weak. So, I get the orange cord, plug in the charger, cover it with a tarp - hasn't rained in weeks, starts tonight and I have a ripped back window.

As I was driving it, I saw a faint glow from the alternator light. Could I possibly not be sending enough juice from the alternator and be driving long enough on the battery? then, when the battery's had enough, it poops out?? Does the AC/Delco system require such a high voltage to be stable?

I know, I need to pull the alternator and have it tested. If it needs replaced, are there alternatives, like with my MGB? Less costly and more effective?

I'm sooooooooooooo close to having a driver!

Remember, after sitting for a while on the charger, it starts.

 

[philman]

I use a 105 amp delco alternator from a '94 camaro. mounting dogs line up correctly. you will need to purchase a pigtail (available on internet) and change the pulley to a v-belt pulley. I went for more amperage to run my ham radio at 50 watts output.

 

[TR3driver]

As I was driving it, I saw a faint glow from the alternator light. Could I possibly not be sending enough juice from the alternator and be driving long enough on the battery? then, when the battery's had enough, it poops out??

Could be, but I doubt that is why the light is glowing. The light basically compares the alternator output to the voltage in the ignition circuit (white wire from switch to coil/ignition module). My guess is that it's telling you there is a lot of voltage drop in that circuit for some reason, like a bad switch or a poor connection. Might be that the bad switch/connection gets hot as you drive around, which lets the voltage droop lower and eventually low enough the ignition craps out.

Best way to start, IMO, is to get a voltmeter or multimeter (one of those cheap DMMs from Harbor Freight will do fine, and they are currently on sale for a whopping $3) and check the voltage first right at the battery. Check it first with the engine off to get a baseline (should be close to 12.6; if it's down around 10.4 then you may have a shorted cell), then start the engine and check it again with the engine at fast idle. It should rise quickly past 13.0 and more slowly up to the region of 13.6-14.4. If it goes past 13.0 and not over 14.4 then the charging system is fine.

If that looks fine, then next I'd check the voltage being delivered to the ignition module. Should be no more than 0.1 or 0.2 volts lower than the battery voltage.

Oops, here's the link to the DMM at HF.
https://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90899
I have several of them myself (I carry a DMM in each car as a sort of talisman against the Prince). Not a Fluke or Beckman by any means, but good value for the price, IMO. And for $3, if it gets dropped into the fan, or run over, or stepped on ... just buy another one.