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HI guys,
I'm a little puzzled.
My 740T 1991 wont start anymore. The car has been difficult to start just before Christmas, but back then I thought that the wire from the coil to the distributor was the cause. After pulling it out and putting it back in, all was fine.
So here what has been done:
- the plugs, plugs wires, ditributor have been changed 1 year ago
- Crank position sensor, changed 2 months ago.
- I here the usual buzz from the gas pump. The relay also clicks.
Before Christmas, when I had this problem, I tried to change the power amplifier with another unit (used, from my 780). I also foooed around with the radio relays, pulling them out, putting back in, putting other units in and out.
This afternoon, I changed the coil with another unit (used, from my 780, and known to work).
From what I know: I have NO FIRE. What could be the cause now? COuld the distributor cap be dead already???
ANy suggestions and help welcomed.
Luc
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Update 2:
Well, since last post, I have changed the battery for one delivering higher amperage at start (875 in cold conditions), and read about grounds in the 700 FAQ.
So I decided to clean those up:
- valve cover to firewall ( 2 of them, one of which was broken): cleaned and replaced broken one
- battery to block: cleaned
- starter to block: cleaned
- inside of the fender, driver side, 2 grounds going to amplifier?
- also cleaned the coil
24 hours later, the car starts like a champ. But will it last?
To be continued, I guess...
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"Well, since last post, I have changed the battery for one delivering higher amperage at start (875 in cold conditions),"
Possibly the extra current from the new battery was enough to compensate for a poor ground on the RSR relay (which I've experienced). That would affect both Coil and Injectors on a turbo.
I'd suggest you locate the RSR and "bypass" it with a jumper wire at the relay harness connector plug.
To bypass the relay, unplug the connector and insert a small "U" of thick wire into the sockets for the two thicker wires (Red and Green-Red). Use fairly thick wire so it will stay in place, like a piece of coat hanger scraped clean for good electrical contact. Be sure to insulate any exposed bare wire with electrical tape or similar.
I've had trouble with that RSR ground. See THIS POST for a picture showing the location of the RSR ground terminal on my non-turbo. I think yours is on the left side.
If that ground was one you cleaned, please forgive this late, redundant suggestion, and accept my congratulations.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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HI there,
Yes, I think I have cleaned those grounds too, which were inside my driver-side fender.
That being said, I had no problems starting the car in the last week since I did a thorough clean-up of the grounds AND replaced the battery.
Now, my dad has tested the old battery's cells and it appears it wasnt giving much power anymore. The battery was 6 years old.
So far, so good.
Thanks for y'all advices.
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UPDATE
First of all, thank you alleycat for your comment and suggestion.
And the plot thickens.
Went back to the car, got another batterie on it (mine had been cranking all afternoon, no more juice in there), and tried to crank it. Nothing.
I then check for some fire in the coil. Wow! We got some spark here! Good.
I try the same with the sparkplug #1. The car suddenly starts, but coughs (of course). Put the cable back into the plug slot. Car starts.
Now, I really dont know what to think. And honestly, I need to have an answer quickly, as I am going to commute all winter long on the highway, and dont want to get that problem because I stopped at a gas station!
It looks like an intermittent fire problem, and that puzzles me. Now, could it be that the coil doesnt get enough voltage from the battery? But then again, this happens randomly, not consistently.
ANy help or suggestions, again, very welcomed.
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Great. Volvos really hate low voltage for starting. Then only true way to test the voltage is during cranking. Lots of batteries will show 12volts sitting. The minute you try to start, drops below 10, no start. Some will sound good cranking, but won't fire.
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Post Back. That's whats makes this forum work.
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If you have no spark at the plugs, pull a plug wire. Plug it into the coil, stick a sparkplug in it, lay it where it will arch against some metal. Try to crank, if you have spark from coil. Then distributor is stopping it somehow.
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Post Back. That's whats makes this forum work.
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