Offroad-Express

Hi all,

I have a 90ish Escudo with the G16A 1600cc 16valve engine. It has a problem where it runs ok for a while up to about 15mins, then it starts to miss, this gets worse and worse, it looses alot of torque, it gets progressively worse until it is barely drivable (you have to rev it up lots then let the clutch out slowly and it will still bog down and stall frequently.)

We have found that if we take the distributor cap off and lightly sand the copper tip of the rotor arm and the points in the distributor cap that the Suzuki will run fine for another 15mins or less, then the same problem starts all over again.

Some times when we go to sand these points they will have a fine white powder crystallized on to them. This problem happens in perfectly dry conditions as well as when the distributor could have got water in it. Originally we thought that the distributor could have been doing this because it was wet, we have tried to silicon it and it does not seem to have made any difference.

Any help would be great as we all love this vehicle and want to get back out into it

try a new rotor/cap/points etc 1st....?

I'd start with new rotor and cap, because you have repeatedly sanded the contacts the gap will be too big for the spark to jump across cleanly, which causes that white build up

And check / replace your leads.

I had a similar problem on my zuk, and it was the HT lead from the dizzy to the coil breaking down. Got worse the hotter it got.

Checked it with a multimeter and found no continuity.

Ben

My guess is the coil is warming up ( normal ) and breaking down eletrically and not giving it a good enough spark . See if you can get another coil to try .

Cleaning the contacts and a broken lead would not degrade so much over that short time , ie I would expect a broken lead to make it run like crap all the time .

just my guess

Cheers
Chris

send me a pm , just around the corner, have spare coil, dist cap and rotor
more that welcome to try

Bob

Bob, That sounds great man, will pm you after writing this

Ben, Your idea sounded the quickest and easiest to try, I haven't tried a new coil to dizzy lead yet but I did check the continuity with a multimeter and found none.

So I went about collecting leads from old cars around home and none of them showed continuity. Anyone got any ideas why this would be the case?

Badnuz, Smurf, Chris, All interesting thoughts, and with the spare parts from Bob I will hopefully be able to isolate the problem.

It should be noted by all that this problem does not seem to be temperature related. Once those points are cleaned up again it will run sweet as for 15mins even if the engine has been hot as and running for an hour. Cleaning points when everything is hot can be a painful experience but when out on tracks we don't wait for the engine to cool down to clean up the points

Thanks everyone for your ideas and thanks very much Bob for offering to lend me the parts

You have already pretty much pinpointed the issue, it's an ignition problem. Without going into any exact diagnosis, looking at the pictures your cap, rotor, leads, coil and probably your sparkplugs are likely to be a bit on the 'dodge.

Checking out your leads involves putting them on the multimeter and measuring the resistance (ohms) through the lead. The resistance will vary depending on the length of the lead, but they should all be around 1k ohms I think. You won't get a continuity reading on ignition leads, as they aren't metal cored and by their design need a huge voltage via a coil to work anyway.

Wether it's a particular component or not thats failing you, age and poor condition of all of these components will further contribute to it not running right.

I'd look to replace the coil as it is probably the most likely suspect from your description, as Rotazuk suggested, but if and when you can afford it, do the rest of the components as well and you are pretty much guaranteed to rid yourself of any ignition issues for many miles in the future.

Pretty cheap insurance that you'll get home again if you like to get off the beaten track...