95 VS V8 running rough & very sluggish, help!!!

[Salan95VS]

I hope you don't have to replace the dizzy - just did mine.....PAINFUL

Yeah I hope to god it’s not the dizzy cause there bad enough to get at just for timing let alone pulling it out & putting another one in

 

[Salan95VS]

That's an ignition module (I'd try module first) or dizzy problem for sure. Nothing else will make tacho jump like that imo...

Yeah the tacho jumps at cold start every morning to about 2 grand before it starts & I’ve heard that is only caused by ignition. I’m currently trying to get hold of another module but no one in near me has one, I’d prefer to get a used one that came off something running & check to see that is the problem then fork out for a new one & pray it works.

 

[BlackVXGTS]

Suggest you replace the coil with a standard Bosch one.

TPS is doesn't need adjusting and could be the cause of your harsh shifts:

THROTTLE POSITION (TP) SENSOR

The Throttle Position (TP) sensor is connected to the throttle shaft on the throttle body unit. It is a potentiometer with one end connected to 5 volts from the ECM/PCM and the other end to ECM/PCM earth. A third wire connects from a sliding contact in the TP sensor to the ECM/PCM allowing the ECM/PCM to measure the voltage from the TP sensor. As the throttle is moved (accelerator pedal moved), the output of the TP sensor changes. At a closed throttle position, the output of the TP sensor is below 1.25V. As the throttle valve opens, the output increases so that, at wide-open throttle, the output voltage should be about 4 volts.

By monitoring the output voltage from the TP sensor, the ECM/PCM can determine fuel delivery based on throttle valve angle (driver demand). A broken or loose TP sensor can cause intermittent bursts of fuel from the injectors, and an unstable idle, because the ECM/PCM interprets the throttle is moving.

The TP sensor is not adjustable and there is not a set value for voltage at closed throttle because the actual voltage at closed throttle can vary from vehicle to vehicle due to tolerances. The ECM/PCM has a special program built into it that can adjust for the tolerances in the TP sensor voltage reading at idle. The ECM/PCM uses the reading at idle for the zero reading (0% throttle) so no adjustment is necessary. Even if the TP sensor voltage reading were to change for some reason, the TP sensor will still be 0% because the ECM/PCM will learn the new value and it will become the new closed throttle value to be used and no driveability complaint will be present because the ECM/PCM learned a new setting. A TP sensor circuit problem will set DTC 21 or DTC 22. If the internal spring in the TP sensor fails, the TP sensor will be stuck high. A sticking TP sensor should set DTC 19.

 

[Salan95VS]

Throttle position sensor could be bad it effects shift pressure and idle decel etc .or the dizzy has moved

Suggest you replace the coil with a standard Bosch one.

TPS is doesn't need adjusting and could be the cause of your harsh shifts:

THROTTLE POSITION (TP) SENSOR

The Throttle Position (TP) sensor is connected to the throttle shaft on the throttle body unit. It is a potentiometer with one end connected to 5 volts from the ECM/PCM and the other end to ECM/PCM earth. A third wire connects from a sliding contact in the TP sensor to the ECM/PCM allowing the ECM/PCM to measure the voltage from the TP sensor. As the throttle is moved (accelerator pedal moved), the output of the TP sensor changes. At a closed throttle position, the output of the TP sensor is below 1.25V. As the throttle valve opens, the output increases so that, at wide-open throttle, the output voltage should be about 4 volts.

By monitoring the output voltage from the TP sensor, the ECM/PCM can determine fuel delivery based on throttle valve angle (driver demand). A broken or loose TP sensor can cause intermittent bursts of fuel from the injectors, and an unstable idle, because the ECM/PCM interprets the throttle is moving.

The TP sensor is not adjustable and there is not a set value for voltage at closed throttle because the actual voltage at closed throttle can vary from vehicle to vehicle due to tolerances. The ECM/PCM has a special program built into it that can adjust for the tolerances in the TP sensor voltage reading at idle. The ECM/PCM uses the reading at idle for the zero reading (0% throttle) so no adjustment is necessary. Even if the TP sensor voltage reading were to change for some reason, the TP sensor will still be 0% because the ECM/PCM will learn the new value and it will become the new closed throttle value to be used and no driveability complaint will be present because the ECM/PCM learned a new setting. A TP sensor circuit problem will set DTC 21 or DTC 22. If the internal spring in the TP sensor fails, the TP sensor will be stuck high. A sticking TP sensor should set DTC 19.

Thanks heaps BlackVXGTS that’s some very helpful information, so what your saying is I should be able to just put the new one on & the ECM/PCM will learn where it wants to be from there?

 

[BlackVXGTS]

......so what your saying is I should be able to just put the new one on & the ECM/PCM will learn where it wants to be from there?

Correct.

 

[Salan95VS]

Alright so I’ve fitted a new ignition module, which I did first to see if anything changed & it still ran like crap then I disconnected the battery to reset the computer & fitted an new TPS sensor. I started the Ute & let it do its thing till it sorted its self out & drove it for about 10 - 15mins, already I’ve noticed that my throttle is much more reactive & it’s got a lot crisper note, still idles a tiny bit rough but no where near as bad as it was. It’s still nothing like it was though so anymore ideas as to what it’s problem could be?

 

[EYY]

Got a good earth to the ignition module? They earth through the body.

Check the vacuum hose that goes through the centre of the manifold and up to the MAP sensor. Most have seen better days and start sucking air and give false MAP readings. Compound issue really - makes them run like crap.

 

[Salan95VS]

Got a good earth to the ignition module? They earth through the body.

Check the vacuum hose that goes through the centre of the manifold and up to the MAP sensor. Most have seen better days and start sucking air and give false MAP readings. Compound issue really - makes them run like crap.

Might have another look at the module if they earth through the body just to double check it does have a decent earth.
Aw righto I’ll have a look around that hose & see if I find anything but wouldn’t that throw a code if it’s getting false MAP readings?
Thanks EYY

 

[EYY]

There is a fault code for vac leak, although it’s activated in some models and not others I believe. Not sure which. Most of the time no codes for map issues though. Cheap to replace that vac line and worth doing if you haven’t though.

 

[Salan95VS]

Aw righto i didn’t know that only some models had the vac leak code activated & others didn’t . Explains why mine probably hasn’t thrown a code then.
I’ll have to double check that vac hose then , is it quite possible that it could also be the MAP sensor it’s self??
It’s really weird cause the more that I’ve driven it after replacing the TPS & ignition module I’ve noticed that some times it runs really good once warmed up & is very responsive & seems really good but then once you pull up somewhere, shut it off & come back, start it again it’s running like crap & shaking everything again.