Thread: D1 3.5l V8 1993

Throttle Position Sensor.
They are the component in the injection most likely to wearas they are like an old style volume control, and often they wear just off idle and give a big flat spot. In extreme cases the ECU cannot compensate for the lack of signal and the engine will stall.
Regard s Philip A

Originally Posted by PhilipA

Throttle Position Sensor.
They are the component in the injection most likely to wearas they are like an old style volume control, and often they wear just off idle and give a big flat spot. In extreme cases the ECU cannot compensate for the lack of signal and the engine will stall.
Regard s Philip A

Old style volume control could also be commonly known a a potentiometer or variable resistor that your throttle cable is connected to at your throttle body which tells the computer how much throttle you want.

I wouldnt be throwing all your electrical parts away for new ones as this will cost you alot of money, you seem to be capable with a multi meter, you just now need to know what your looking at.

An ignition lead should be reading close to continuity (closed circuit) on your Ohms meter so that 5.7 what ever, what range was that in?

Your coil could be 1 of 2 types, a resistor coil or non resistor coil, all ignition systems need a balast resistance to work properly so you need to have play and find out from someone else with a 3.9 what resistance is across theirs.

The surpressor could be faulty, disconnect and try it out, they do do stupid things sometimes that end up hard to trace, it wont hurt anything but your radio reception if you disconnect as im assuming you dont have points in your dizzy.

If all else fails, put it on a tune up machine, it should tell you what is going on a lot quicker and easier than going through all this and I would be doing that before you spend any extra money on things that might not be broken.

Originally Posted by mcrover

An ignition lead should be reading close to continuity (closed circuit) on your Ohms meter so that 5.7 what ever, what range was that in?

The surpressor could be faulty, disconnect and try it out, they do do stupid things sometimes that end up hard to trace, it wont hurt anything but your radio reception if you disconnect as im assuming you dont have points in your dizzy.

If all else fails, put it on a tune up machine, it should tell you what is going on a lot quicker and easier than going through all this and I would be doing that before you spend any extra money on things that might not be broken.

When I took the reading across the lead I put the multi meter on the ohms sign & hooked a lead up to each end. when it gave me the reading on the screen it said 5.7 then a little tiny k& then the ohms sign. So I assumed that meant 5.7 ohms ??

There is no points in the dizzy as it is electronic looking stuff....

The tune up machine is a last resort as the only people I know who would have the right gear would be the local stealer......

Thats 5.7k ohms, depending on what type of leads they are I think it should less than that but it's been a while since Ive played with a petrol motor.

Try checking the other leads, they should be all around the same, and this will tell you if 1 or 2 leads have broken down.

Failing that, there must be another Mechanic in Bundy that has a tune up machine, I know a bloke that has an old Sun diagnostic in his shed down here, even most mobile mechs have them in their vans down here.

see how you go and I'll see if I can find out some specs to get a better grasp on this.

Originally Posted by Gidget

So half way up a hill at cruiser park on the weekend the motor just cut out then sort of like bunny hopped for a few times before dying.

Don't know if this is any help but...

I've got a RR 3.5L with electronic ignition. A while ago it started to bunny hop, cut out (when idling or reving hard) going up a steep hill climb. Had never happened before. Got home with plenty of trouble. I had noticed the battery voltage dropping, so i started with an auto elec. Outcome was a bad connection from the alternator to the battery. Elec ignition was just cutting out when the voltage dropped. $20, and was running fine again.

My 3.9 V8 was doing the same thing, then all of a sudden it just stopped. Turned out to be a bad connection to in the wiring at the fuel pump.

How did you go???

I see your Secondary (HT and + terminal) resistance of 5.7 to 6.5 which is actually 5,700 - 6,500 ohms.

I currently have a 94 disco (with same coil as yours I think albeit your Amp may be fixed to side of Dizzy and not seperate type in later models) and is misfiring (and not a fuel prob or alternator prob like Bulldogs) with a secondary resistance more than yours of 7,500 ohms. I think this might be abnormal and a Primary (+terminal to - terminal) resistance around 1 ohm or less which seems normal.

The water mist spray test on HT leads indicates some shorting out occuring.

I will be changing my leads next weekend and before I jump in and look at coil replacement and distributor probs if that does not work.

If this does not work the 13 year old MAF meter starts to look like possibly next and very expensive culprit.

I will let you know how I go

guys dont forget to eye ball the sockets that the leads go into and the inside of the dizzy cap...

multimetering your leads wont tell you the full story either... Grab and old plug and file the earthing electrod off of it, attach a hoseclamp to the threaded part to hold an aligator clip on it. This is a test plug...

hook up your battery charger to prevent you from getting voltage problems during the test from the alternator or a crook battery and then pull the plug lead from one cylinder and install the test plug, make sure it has a good earth..

fire it up, it will run rough as its not firing one one pot but it will run..

look for a nice blue spark, if its yellowish youve got resistance problems in the HT side..

IF it "dances" (you'll want good eyes for this check) then the problem is in the LT side of the coil most commonly the condenser isnt doing its job or in the case of points based vehicles the points are arcing.