Still have engine problems, not happy
Discussion
Having had some irritating issues a while back I put my car into Neil Garner, who couldnt find anything wrong apart from advising me to run on Super and Mark(Blitzracing) who couldn't find anything conclusive.
However, I still have problems of horrible to pull away, in my view far worse than normal for a HC. Cruising at approx 45, you can feel the car hunting ever so slightly, does improve as you go faster. This overall problem came on all of a sudden a few months back now and I have been going round in circles since.
From cold it will almost die when you try and pull away, this does improve with heat, but it's not an easy thing to pull away with out horrible judders.
Last night driving home I had new issue of stalling. The first time it wouldn't fire for about 5 mins, eventually did, but then revs wanted to just drop off to 100Rpm or nothing and die again. Managed to keep them up at junctions etc and get home. So far the following has been investigated :-
Cleaned stepper motor
All ignition componets replaced
Lambdas checked
AFM voltages checked
Throttle Pot voltages checked(swapped it out, but no different)
And countless other things
Fitted new Vac advance unit(swapped it out, but no different)
Timing checked
Next stop was a plan to go down To Dulfords, but I'm worried I wont get there.
Can anyone think of other stuff to check.
I still believe it's a fuelling issue, blocked filter maybe or inefficient pump, knackered injector??
Seriously getting to the end of my teather now. If I could guarantee getting down to Devon I would do it, just concerned it will stiop all together on the M5.
However, I still have problems of horrible to pull away, in my view far worse than normal for a HC. Cruising at approx 45, you can feel the car hunting ever so slightly, does improve as you go faster. This overall problem came on all of a sudden a few months back now and I have been going round in circles since.
From cold it will almost die when you try and pull away, this does improve with heat, but it's not an easy thing to pull away with out horrible judders.
Last night driving home I had new issue of stalling. The first time it wouldn't fire for about 5 mins, eventually did, but then revs wanted to just drop off to 100Rpm or nothing and die again. Managed to keep them up at junctions etc and get home. So far the following has been investigated :-
Cleaned stepper motor
All ignition componets replaced
Lambdas checked
AFM voltages checked
Throttle Pot voltages checked(swapped it out, but no different)
And countless other things
Fitted new Vac advance unit(swapped it out, but no different)
Timing checked
Next stop was a plan to go down To Dulfords, but I'm worried I wont get there.
Can anyone think of other stuff to check.
I still believe it's a fuelling issue, blocked filter maybe or inefficient pump, knackered injector??
Seriously getting to the end of my teather now. If I could guarantee getting down to Devon I would do it, just concerned it will stiop all together on the M5.
My Chim 400 has been doing this too. I don't know enough about these engines yet, but I've tried cleaning the stepper motor which, although improved things slightly, still hasn't fixed it totally.
It seems to misfire on cold start, I feel hunting when trying to accelerate steadily and a terrible idle, followed by a stall after a minute or so. Difficult to pull away unless I rev high and slip the clutch.
It seems to misfire on cold start, I feel hunting when trying to accelerate steadily and a terrible idle, followed by a stall after a minute or so. Difficult to pull away unless I rev high and slip the clutch.
Speak to Rich at Dulfords and he can arrange collection for a small fee.
Two things to rule out if you havent already;
Try running with the Stepper motor disconnected (several threads on here of how you do this).
Try running with Vac advance disconnected (dont forget to block up plenum end)
The Vac advance on mine has cuased some of your symptoms so i run with mine disconnected now. But my guess would be an issue with your injectors.
Two things to rule out if you havent already;
Try running with the Stepper motor disconnected (several threads on here of how you do this).
Try running with Vac advance disconnected (dont forget to block up plenum end)
The Vac advance on mine has cuased some of your symptoms so i run with mine disconnected now. But my guess would be an issue with your injectors.
ECU Temp sender - not the gauge one, the one into the inlet manifold
Air bleed to stepper screw - controls how much air is available to the stepper, located at butterfly
Air leak from brake servo - Had this on my S, took weeks to work out the issue
Fuel filter (been a lot of dodgy fuel reports around the forums lately)
Have you still got all your cats in the exhaust, blocked?
Air bleed to stepper screw - controls how much air is available to the stepper, located at butterfly
Air leak from brake servo - Had this on my S, took weeks to work out the issue
Fuel filter (been a lot of dodgy fuel reports around the forums lately)
Have you still got all your cats in the exhaust, blocked?
Reading afew posts on here as My idle has been an issue... The stepper motor can check out righ (volts / resistance etc)... but may still not work... There is a company who makes a bypass or some alternative for this problem part and it was only about £20... would be worth a try... Was it ACT??
This is it....
This is a common problem with many TVR V8 engines. If the problem persists after checking everything, SC Power sell an air restrictor to the plenum that controls idle speed. This works fine and is not expensive.
This is it....
This is a common problem with many TVR V8 engines. If the problem persists after checking everything, SC Power sell an air restrictor to the plenum that controls idle speed. This works fine and is not expensive.
Edited by TVR Beaver on Friday 7th August 11:00
Temp sender changed by Neil Garner as a precaution. No change.
Will look into the brake servo leak, would have thought that would affect braking though, which is fine.
Not so sure the stepper is at fault, remember it hunts at 45, so that would neglect any stepper issues. Accepted it could be the cause of teh low rpm problems though.
Will look into the brake servo leak, would have thought that would affect braking though, which is fine.
Not so sure the stepper is at fault, remember it hunts at 45, so that would neglect any stepper issues. Accepted it could be the cause of teh low rpm problems though.
I know its obvious, but check that the ECU multi-pin connector is completely dry. Rain water has a nasty habit of travelling down the loom. I had a complete stall the other day, split the ECU connector and gave it a good flick and there were droplets of water. While you're down there in the footwell also check the fuel pump and injector relay sockets are dry.
As for your misfire problem, a diagnostic session on a rolling road might solve it.
As for your misfire problem, a diagnostic session on a rolling road might solve it.
Edited by davep on Friday 7th August 12:45
Have you had the plenum off ?
Just wondering on a trumpet having come loose and sat on top of another, severely restricts air flow and on mine gave idle issues and running issues, although not as severe. Mines a different set up however and my ECU won't be making changing based on narrow band input and chasing the mixture, it just didn't work right
Just wondering on a trumpet having come loose and sat on top of another, severely restricts air flow and on mine gave idle issues and running issues, although not as severe. Mines a different set up however and my ECU won't be making changing based on narrow band input and chasing the mixture, it just didn't work right
Edited by Johno on Friday 7th August 14:30
Do the faults relate to movement of the car?
Mine drove me crazy with similar symptoms.
A Kent TVR specialist kept having the car in and giving it back with a big bill. A few miles later this intermittent fault reoccured.
We later discovered they were past the limits of their abilities. Having run out of ideas, they weren't actually doing any work at all, just parking it for a few days, then billing me.
If you're not DIYing the repairs, make sure the garage is actually doing the work.
When I took it away and sent it somewhere with rollers, it still didn't disclose the root cause on the rollers.
The rollers don't replicate G-forces on the car.
It was Carl Baker who finally pointed to the culprit.
He said loom fault and recommended engine loom replacement. I thought about it. A new loom as a possible fix, or replacing everything with an aftermarket ECU. Not using a loom adaptor to plug into the original loom, but a complete new custom engine loom for the new ECU.
I was past taking prisoners, so I had everything removed and the new loom fitted.
When the old loom was being removed, two things were found. A break in the loom down between the back of the block and the bulkhead. The other was that the parts you need to remove to get at that section of loom hadn't been removed in years.
Carl had specifically advised checking that part of the loom, so I had paid the Kent specialist to check it. Had the lazy git done what he was paid for, the fault would have been found. I wouldn't have ended up spending out on a new everything.
Anyway, the broken end of an earth wire was touching the block and making a good earth. The natural springiness of the wire was holding it in contact.
The motion of The car would sometimes break the contact briefly, of make it high resistance.
Under bonnet temperature, age and some really dubious manufacturing techniques by TVR, that Carl described mean that looms must be increasingly suspect in elusive faults. No wiring lasts forever.
If anyone gets their car worked on in Kent and doesn't know who I'm talking about, PM me.
Mine drove me crazy with similar symptoms.
A Kent TVR specialist kept having the car in and giving it back with a big bill. A few miles later this intermittent fault reoccured.
We later discovered they were past the limits of their abilities. Having run out of ideas, they weren't actually doing any work at all, just parking it for a few days, then billing me.
If you're not DIYing the repairs, make sure the garage is actually doing the work.
When I took it away and sent it somewhere with rollers, it still didn't disclose the root cause on the rollers.
The rollers don't replicate G-forces on the car.
It was Carl Baker who finally pointed to the culprit.
He said loom fault and recommended engine loom replacement. I thought about it. A new loom as a possible fix, or replacing everything with an aftermarket ECU. Not using a loom adaptor to plug into the original loom, but a complete new custom engine loom for the new ECU.
I was past taking prisoners, so I had everything removed and the new loom fitted.
When the old loom was being removed, two things were found. A break in the loom down between the back of the block and the bulkhead. The other was that the parts you need to remove to get at that section of loom hadn't been removed in years.
Carl had specifically advised checking that part of the loom, so I had paid the Kent specialist to check it. Had the lazy git done what he was paid for, the fault would have been found. I wouldn't have ended up spending out on a new everything.
Anyway, the broken end of an earth wire was touching the block and making a good earth. The natural springiness of the wire was holding it in contact.
The motion of The car would sometimes break the contact briefly, of make it high resistance.
Under bonnet temperature, age and some really dubious manufacturing techniques by TVR, that Carl described mean that looms must be increasingly suspect in elusive faults. No wiring lasts forever.
If anyone gets their car worked on in Kent and doesn't know who I'm talking about, PM me.
Plenum has been off recently and all ok. I have done majority of things myself. only used neil as last resor as I cant find a thing. Happy to mend it myself, if I could just locate teh bloody problem, grrr!!
I am tempted to just change teh fuel filter anyhow, they are prey cheap and I dont think it has ever been done. Might not cure it, but it is one mor ething ruled out.
I am tempted to just change teh fuel filter anyhow, they are prey cheap and I dont think it has ever been done. Might not cure it, but it is one mor ething ruled out.
The other things Carl had found was that when TVR soldered their wiring into the loom, the quality of the soldering was variable.
Sharp peeks of solder were just taped over, and then wires bundled together and taped again. Over the years the sharp peeks penetrate the insulation and into the next wire. The resulting short circuits can cause all sorts of trouble.
The other problem was water ingress. Water leaking onto the wires, particularly in the passenger footwell travels within the insulation and collect at the lowest point. Carl found that the insulation contained little but green dust of oxidised copper in places.
Leaks from the heater pipes and valve seem to be the usual source of the water as these run down the heater pipes and drip onto the ECU loom.
When you have verified all the parts, it comes down to the wires that join them.
Hopefully it’s not in your case, but you seem to have covered the usual suspects.
Sharp peeks of solder were just taped over, and then wires bundled together and taped again. Over the years the sharp peeks penetrate the insulation and into the next wire. The resulting short circuits can cause all sorts of trouble.
The other problem was water ingress. Water leaking onto the wires, particularly in the passenger footwell travels within the insulation and collect at the lowest point. Carl found that the insulation contained little but green dust of oxidised copper in places.
Leaks from the heater pipes and valve seem to be the usual source of the water as these run down the heater pipes and drip onto the ECU loom.
When you have verified all the parts, it comes down to the wires that join them.
Hopefully it’s not in your case, but you seem to have covered the usual suspects.
Same sort of problem on 3.9 V8 plenum. The butterfly was actually getting stuck in the body, it didnt happen by just flicking the throttle whilst stationary, it appeared that the induction (if thats the correct term as I am no mech) on deceleration slammed the butterfly down and it was getting stuck!
Lifted the manual throttle stop a turn to hold it away.
Lifted the manual throttle stop a turn to hold it away.
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