Starter problem

[UK Muppet]

I'm almost at the stage of starting my engine for the first time. The engine was apart when I bought the car 11 years ago ( S2 2+2 4.2 auto) and I have rebuilt it along with everything else on the car. Last week I put a battery in place and connected the cables, when I turned the key the engine turned over, excellent I thought but it continued to crank when the key was turned off and removed. The only way to stop it cranking was to disconnect the battery. A whack on the side of the solenoid released it but each time I tried cranking it would stick again. Starter is a M45G pre engaged type, cleaned internally and new brushes fitted.
So after a number of brews I chose to remove the starter, what a fun job that is. With the starter on the bench and connected to the battery with jump leads it worked exactly as it should and the solenoid released every time. Okay put it back and see what happens. No change, solenoid sticks every time.
I thought the solenoid relay might be the problem but it works perfectly and still looks new inside. Also took the ignition switch apart and that works correctly.
I've now removed and refitted the damn thing 3 times with no change but I have now got quicker and have found ways to stop losing sockets and starter bolts that drop into places you cannot see or touch.
Anyone got any ideas to try?
Thanks
Tony

[lowact]

Any chance you've wired up the starter relay incorrectly? What happens if, instead of disconnecting the battery to stop it, you pull the red-white wire off the starter relay, then switch off the ignition?

[abowie]

Any chance you've wired up the starter relay incorrectly? What happens if, instead of disconnecting the battery to stop it, you pull the red-white wire off the starter relay?

I must admit that was my thought as well.

[lowact]

The starter relay W2 terminal needs to be grounded. You are auto, so the starter solenoid relay W2 terminal should have a BG (?) colored wire that connects to ground via the auto trans safety switch?

[UK Muppet]

Thanks Colin and Andrew, I thought I had connected the solenoid relay as it was originally but could be wrong, see attached photos.





According to the wiring diagram its connected correctly,
W/Y on W1
N on C2
R/W on C1
B/G on W2

I will try disconnecting the R/W wire as you suggest and see what happens, will get back with the result.
Thanks
Tony

[UK Muppet]

I disconnected the W/R wire whilst it was cranking and it didn't do anything except give enough time for a cup full of oil to pour out of the pressure switch hole before I could disconnect the battery.
My only guess now is, could it be the spring on the solenoid that does not have enough force to push the mechanism back? It appeared to be okay when dismantled. No idea what the force should be and there is no info in the workshop manual, not even a mention.
Something I did notice when I turn the key to the on position, there is a faint noise like a relay contacting (maybe) somewhere near the battery, I can't locate it on my own due to being on the other side of the car.
There's only the 4TR and 3AW in that area, could they be doing something weird? Its all witchcraft to me.
Thanks
Tony

[mgcjag]

Hi Tony....do you have a wireing diagram....I just looked the starter has a large battery cable and one other wire from the starter relay that operates the solonoid ...disconnect this thin wire from the starter and connect it to a meter......now you can play with the starter key without the starter spinning.....operate the key and you should see 12v at the meter.....release the key 12v should go...if the 12v stays then thats your continuous cranking....let us know what happens

[UK Muppet]

Yes Steve, I have the wiring diag. (coloured version) and the workshop manual.
I did as you suggest and the 12v appears on the wire at the start position and disappears when the key is released. Yesterday I took the starter out again and went to an auto electrician, he just wanted to sell me a new starter and wasn't interested. I later took the solenoid off and increased the length of the return spring from 31 to 40mm. It did appear to stretch fairly easily. Now with everything re-installed it still continues to crank when the key is turned off but now once the battery is disconnected the solenoid is returning to its correct position ie. the starter does not crank when the battery is reconnected. Previously I would have to tap the side of the solenoid to release it. So in my mind the return spring is just not strong enough to pull the pinion back whilst its cranking but sufficient when stationary.
Another thought I just had is the hold on winding inside the solenoid, could this be shorted internally?
Maybe I should just get a new starter, solenoids seem to be unavailable.
Tony

[mgcjag]

So do you have the same issue testing the starter on the bench?...in your first post it works on the bench but not in the car which pointed to the relay etc....so yes could be internal and intermittent.....mount the same way up on the bench and see what happens

[DWW]

He already said it works fine on the bench

[UK Muppet]

Yes it works fine out of the car and the relay and ignition switch have been dismantled and checked, both working correctly.
I called at a friends garage yesterday and he insisted he checked it out, his comment was, nowt wrong with that.
The price I was quoted for a new starter seemed very reasonable, £132 but I said it was for a 4.2 jag. Would there be any difference in starters between say an xj6 and E? I tend to avoid mentioning E type when buying parts as the reaction seems to increase the price.
Tony

[mgcjag]

Yes there are different starters....was your quote for a new original type or modern high torque unit..look at sngb website for options....but beware the high torque units....dont just assume they are direct replacements as there are different types etc

[UK Muppet]

The quote was for an original type.
My question is, is there a difference between a Xj6 starter and an E type, perhaps torque but don't see why it would be different.
Thanks
Tony

[lowact]

Before buying a new starter I would want to double check that there is no external wiring issue that is leaving some residual voltage on the solenoid; that is not enough to engage the pinion but is enough to hold it engaged, until the battery is disconnected. Maybe by, when the key is off and the starter is continuing to crank, pulling the WR wire off the relay and measuring the voltage between the positive post and the WR wire?

[mgcjag]

Tony...as my previous post...yes E type and XJ6 starters are different.....within the xj6 range there were various starters.....you can use an xj6 starter if you get the right one and are prepared to modify it to fit .....Steve

[dxke38]

There are are two or three different ring gears with different number of teeth. If you don't have the correct starter pinion for the ring gear the starter will engage but not release easily.

[dxke38]

To clarify, if the starter doesn't disengage the solenoid will still be energised.

[lowact]

Oh, so it does, on my old starter.i didn't realise ...
Correction, no it doesn't, using a meter just shows that the solenoid and the motor terminal share a common earth ...

So, if the solenoid trigger (WR) is back-energised from the motor terminal, how does such a starter ever disengage?

[UK Muppet]

Well after spending far too much time on this I decided to throw the towel in, I don't like being beaten but in this case I have to admit defeat. I am convinced its the return spring on the solenoid plunger thats too weak but as you cannot get solenoids anymore there is no way I can prove it.
Anyway I found a Powerlite RAC303 on fleabay for a good price so will see what happens with that when it arrives later this week.
A question for Steve as he seems to have had some correspondence with Powerlite, do I use the spacer or just the dowels with the Powerlite? I haven't been able to find anything definite after reading lots of threads on the forum, some say with the spacer some without.
I would prefer to put the starter in once as being an auto its far more difficult than a manual, the top bolt is really difficult to get to due to the size of the bellhousing and the position of the kickdown mechanism. From the top I can just touch the bolt head with my fingertips and the alignment has to be within about 10 thou to get the bolt in. I can turn the bolts from inside the car, Just, but cannot hold the starter at the same time so alignment has to be spot on. I'm considering making studs as they might make it a bit easier.

[mgcjag]

Hi Tony.....spacer..depends what actual starter you have
I'm my opinion a Powerlite isn't a direct replacement and will not fully engage with the flywheel....you will need to measure the pinion throwout and then the distance between bellhouseing and flywheel.....then work out how to fit it....without the spacer you can't use the ring dowls so then the fit is a bit sloppy.....Steve viewtopic.php?f=3&t=20860&p=169962&hili ... er#p169962