15 replies to this topic

[thatclairgirl]

I've had a good search in the forum and nothing seems to tie up exactly with what I'm having issues. So problem as follows. 1988 Mayfair 998 Engine. No upgrades but air filter. Car wouldn't start so after a quick trip to the garage with suspected starter motor issue it turns out it's a duff battery. Since collected had an issue following day that headlights wouldn't switch on. Checked connection on fuses and light switch under dash and lights came on. Assumed lose Fuse issue. But since this the red light stays on the dash (coincidence?)

 

Also noted that this morning the car juddered around 2000rpm in each gear and only smoothed out after a good 20 minute run at 50-60mph. 

 

Could any of these issues be connected or am I looking at two separate issues? Alternator at fault and sparks etc. Any ideas welcome. I'm not hugely tech minded but I will have a go. 

[Mon_Papillon]

I'm sure more intelligent forum members will be along soon but it may be worth testing the output of the alternator...

[Stevie W]

Hi,

 

The red charge warning light staying on does usually indicate the alternators not charging. The duff battery you had might just've been flat due to this. As above, a check-up of the alternator would be a good place to start!!

It's also worth checking the battery and engine earth cables in case one these is disintegrating or is corroded where it bolts to the bodywork. Similarly, check the solenoid connectors and the heavy duty starter cable connections.

 

It would also be worth checking all the fuses on the bulkhead as these can suffer from corroded connections on both the actual fuses and the wires connected to the fuse box. Poor connections here can give you all sorts of weird electrical issues. If you find any corrosion, it's easier in the long run to replace the whole fuse box. These are relatively cheap and will guarantee to sort most electrical gremlins out! 

 

With the weather we're having at present, any damp or moisture that can get in around any electrical connection will be more likely to show up any inadequacies in the electrical system!

 

Cheers, Steve.

[thatclairgirl]

Well the garage said they checked the alternator and the ignition system to make sure the power was there and found no fault with it so I'm hoping it could be a loose connection/poor cable somewhere. I will have a peek and see what turns up. I didn't change the fuse box too long ago so I will give it a clean up and pop some new connections on. 

 

Could this also cause the juddering I'm getting around 2000rpm or is this likely to be a fuel mix/sparks/HT lead issue? 

 

Thanks for the help!

 

Clair

[Stevie W]

Hi Clair,

 

It's difficult to tell if this is the cause of your juddering. If the engine earth strap is clean and secure and all other electrical connection are ok, it could just be that your car needs a bit of a tune up, The fact that the juddering goes away after a long run would suggest a possible weak mixture or ignition/timing issue that only shows itself with the engine cold.

Has the car been rolling road tuned after the air filter upgrade? Simply fitting an upgraded air filter without any mixture adjustment will mean the mixture could be weak if the air filter flows more air than the standard one.

 

Have you still got the no-charge red warning light on all the time or has this now been fixed?   

 

Cheers, Steve.

[thatclairgirl]

Hi Steve,

 

The air filter was fitted when I bought the car about 3 years ago so I'm not sure. In my time I haven't had it on a rolling road but it has been tuned up nicely a few times (had the carb re-furbed) and run beautifully. Might be worth me having a look at this. It's been off the road for a few months in my garage and since going back on the road it had run nicely (about a month) until this morning when the juddering started. 

 

I will have a look at connections and electrics as suggested when I have chance later and let you know. The light is still staying on when the car is running but thinking about this this only started after the loose connection on the lights so I'm wondering if I have caught something etc. Once I have some more info I will come back to you. Thanks for the pointers!

 

Clair

[Stevie W]

No probs Clair,

 

It is starting to look like something electrical, good luck tracking it down!

 

Cheers, Steve.  

[KernowCooper]

If the red charge light is on with the engine running and does not go off even if you take the revs above then it indiates there is no charge from the alternator to extinguish the charge light. If your current garage says it ok then I suggest you take it to a auto electrician, the juddering could be running weak due to a incorrect mixture in the colder weather, when was the last time it had a engine tune?

[thatclairgirl]

So just to update you all. The alternator was at fault and has now been replaced. I've also swapped out my spark plugs as I had a duff one and the mix was weak. Seems to running great again. Thanks for the advice guys!

[Stevie W]

Well done Clair,

 

Glad you're up and running again!

 

Cheers, Steve.

[thatclairgirl]

Okay the judder is back The little beast drives perfectly until I hit 4th gear and then it will not go past 50mph and 2500revs. While at that speed I pulled the choke a little and the speed dropped by a couple of miles an hour and the revs dipped by about 200-300 revs. There is also a slight judder after 40mph and it loses power going up hill. 

 

My first thoughts was poor mix as it also seems to go through fuel pretty quick as well? I have got a slightly dodgy fuel guage (it always says I have less than I have by a quarter tank!!) Before I attempt anything I wanted to check with you helpful folk.

 

Aiming to try and find a rolling road for a proper tune up soon but I just can't find anywhere/haven't had time.

[Phil-R]

When were the ignition HT leads last changed?

When they're past their best, the insulation on them can break down and they short out on other wires or anything else close by. It tends to happen more in damp or wet conditions, and sometimes only at certain revs. Typically its fine at idle, happens around 2 - 3k rpm then you can push pastthat and it revs fine at higher revs. Sometimes it can go away after a period if driving as the engine heat dries the leads out

If you can recreate the problem when not in gear, try again at dusk with the bonnet open. It's fairly clear when it happens as you can spot small sparks jumping from the HT leads. Keep your hands clear of the leads!

Edited by Phil-R, 12 January 2016 - 02:44 PM.

[thatclairgirl]

Okay so in stupid peoples terms I need to pop it in to neutral and rev to see if it hits 2-3k rpm and sits there and look for sparks near the leads?

 

It has probably been two years since they got changed :/

 

I'm a newbie so I'm just learning the basics. 

[Phil-R]

Exactly that. You can either open the throttle from under the bonnet and be careful to keep your body away from the leads and fan belt, or better still, get someone else to press the accelerator while you watch.

Sometimes you won't be able to get it to judder without driving and putting the engine under load, but its worth a try.

Edit: Although, HT leads normally last longer than 2 years

Edited by Phil-R, 12 January 2016 - 03:18 PM.

[dklawson]

Since you reported that the problem starts above a certain RPM and the car will not go more than 50 MPH, I would start with a general tune up.

 

Replace the air filter no matter how old it is.  Set the valves with the engine cold.  Check the spark plug gaps and make sure none are carbon fouled.  Examine the distributor cap and rotor (inside and out) looking for signs of carbon tracking and/or cracks.  Replace any suspect components.  If the car uses points, replace the points and condenser.  Don't assume there is anything wrong with the ignition timing, that seldom "goes out" on its own.

 

With all that done, take the car on a drive.  If the problem returns, look at the fuel level in the carb.  Hopefully you have an HS series carb fitted which makes checking the fuel level easier.  If the level is low, look for and replace any inline fuel filters, clean and adjust the float valve, and try a test drive again.

 

Your car's inability to go over 50 MPH and its response to changes in the choke suggest there is not enough fuel.  However, a basic tune up as I suggest doing first may eliminate other contributing factors.