420 sel intermittently running bad.
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420sel
420 sel intermittently running bad.
Hi all we have fitted a new engine as the old one dropped a timing chain. Story is since the new motor has been fitted the car will start most times with some throttle, it struggles and hesertates to accelerate until the point of it stalling. This issue dose seem to be intermittent as some times it will start and run ok and rev to red line without a problem until it's put in gear then it will bunny hop and carry on. Dose any one know is there maybe a sensor on the flywheel or torque convertor that sends a signal to the computer? We have been through a lot of diaignosing so far without any 100% fix.
We have had it going and moved the distributor a tiny bit and it revs up grate then goes bad once put in gear to move it.
Please if someone with some knowledge of these motors might know where to start and are willing to help us diagnose the problem could help me out it would be very appreciated.
We have had it going and moved the distributor a tiny bit and it revs up grate then goes bad once put in gear to move it.
Please if someone with some knowledge of these motors might know where to start and are willing to help us diagnose the problem could help me out it would be very appreciated.
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420sel
Hi glen and thinks for your input. I just checked what you said and all looks fine. We have used every thing from the original motor that was running fine before it broke the chain. I'm guessing it's a sensor or somthing that dose not want to inter change with the new motor really not sure tho.
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420sel
when it runs it is very rich with black smoke when you can give it full throttle.
Also this is something we have not been able to work out. We have a sensor or somthing with a green wire going into it on near the bell housing it runs to what looks like A coil modulator which I'll put a pic of. We are starting to wonder when you connect the box to the motor is there somthing that has to be linged up so all runs right?
Sorry I can't work out how to upload pics if someone can let me know that would be good to.
Thanks luke
Also this is something we have not been able to work out. We have a sensor or somthing with a green wire going into it on near the bell housing it runs to what looks like A coil modulator which I'll put a pic of. We are starting to wonder when you connect the box to the motor is there somthing that has to be linged up so all runs right?
Sorry I can't work out how to upload pics if someone can let me know that would be good to.
Thanks luke
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Joined: Feb 2016
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From: Cincinnati, Ohio
mb, saab, acura, dodge
I believe that's the crank sensor. Also, you mentioned turning the dist. The rotor has to be pointing to no. 1 when engine is on top dead. If you watch the tach when things go wrong, it may indicate a crank sensor issue if it fluctuates when the rpm doesn't.
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420sel
Thanks glen. I will look at that tomorrow, I had it going before and reving up fine still a little rough at idle. Most times when I put it in gear it dies and if I can get it to move it is gutless.
So is there any trick for installing the gearbox like dose the fly wheel have to be aligned with anthing at the back of the motor that can give dramas with the crank sensor?
So is there any trick for installing the gearbox like dose the fly wheel have to be aligned with anthing at the back of the motor that can give dramas with the crank sensor?
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Member
Joined: Feb 2016
Posts: 192
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From: Cincinnati, Ohio
mb, saab, acura, dodge
Generally there's a red paint mark on the dist. screw. Make sure all the grounds are tight. As far as flywheel, I think it only goes on 1 way.
Did you change the C.I.S? Maybe the center pin is stuck
Did you change the C.I.S? Maybe the center pin is stuck
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Joined: Feb 2016
Posts: 192
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From: Cincinnati, Ohio
mb, saab, acura, dodge
Possibly a wire broke in harness when moving them around. Old cars and brittle wiring. Don't forget to check the fuel. I did one of those and some nice person put water in the tank. Took me a week to figure that one out!
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420sel
Thanks glen, I will check all the above soon and see how we go. Most Likely a wire as it's intermittent. It like somthing is responding when it put in gear as it hops in reverse and in drive just really under powered.
Thanks again
Thanks again
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420sel
Hi glen, we have been through most things now. It seems to be running a little better. Still at idle it revs from idle to 1000rpm then back to idle constantly. I can hit the throttle and it's fine revs right up when put into gear it still dose the rev up and down thing. One thing Iv noticed is while it's running if I turn the dizzy a tiny bit it make a huge result in how the engine performs. My past dealings with car last are you can nearly turn the dizzy both ways with minimal diffrance to the way the engine runs.
Have you got any other tips for me?
Thanks again.
Have you got any other tips for me?
Thanks again.
Member
Joined: Feb 2016
Posts: 192
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From: Cincinnati, Ohio
mb, saab, acura, dodge
The dist. Is for aligning rotor to no. 1 cylinder for firing. The crank/ flywheel sensor is actually the reference point for the computer. Maybe spray intake and boots with brake cleaner to check for leaks? That lower plenum could have an open port or cracked boot. Also, the throttle switch defective or miss- adjusted? Tap the idle motor while it's doing it or unplug it. Maybe you could send me some pics? I'll PM my email.
