Injector Upgrades - The Vectra Injector Mod is Dead!

Injector Upgrades - The Vectra Injector Mod is Dead!

Author
Discussion

combine04

71 posts

126 months

Wednesday 19th May 2021
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Hi folks, a brief bump of this thread to share some experience and comments. I'd like to call out immediately that I am not mechanically minded, but a fast listener/learner and happy to lean on friends with more experience (such as you lot!!) and pay for specialists.

I fitted these new injectors to an otherwise standard Chim 400. At the same time, I decat'd via a Clive F Y piece (precats, at the time, still in place). The car also had new spark plugs and an ACT induction kit fitted. The aim was to get a slightly under powered 400 up to healthy running figures.

Driving the car away, it was a little jumpy which I put down to the car relearning the cat removal with the new Y piece. However, the one hour drive home showed a fairly major misfire. Back home, checked the plugs and all were black, showing over fuelling. Cleaned the plugs up, drove it 5 miles, issue returned. Unfortunately I don't have a Windows laptop, so cannot run Rover Gauge.

Now, the car has been in having a lot of general upgrades with a well known TVR specialist on the south coast. They have adjusted the AFM and the car runs fine - perhaps a few flat spots, but again, it's had a few other bits added (new throttle pot, new throttle cable, plenum spacer) and is going to Joolz at Kits and Classics end of this month for an Emerald.

Interesting updates from yesterday - I spoke to another well known company, who specialise in developing V8 engine builds. He was interested to know which injectors I'd fitted and mentioned he'd had approx 8-10 other people state the same experience as above...

I hope this is useful feedback.




drcarlos

28 posts

191 months

Wednesday 19th May 2021
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I have these injectors fitted in my 400 along with some other fairly serious mods (Stage 3 heads, different cam, Stage 3 Intake package and a Megasquirt ECU system with wasted spark ignition) I am currently running it off tune when I drive it and it does jerk (massively on a trailing throttle) and overfuel, but it doesn't miss.
I put this down to the lack of Lambda sensor (prior to my acquisition it had a decat and sensor fitted but now I have a standard cat in place) and the car not being tuned for the way it's expecting to run.
I would expect that putting in larger injectors and pulsing them with the signal required for the older Lucas ones would have a severe impact on running and that your conversion to Emerald along with the requisite map will sort things out.
I learned a fair bit from modding my Impreza that every mod needs to be accounted for in a tune otherwise there are issues, the poor running you see in the RV8 is exponentially amplified in a BJ255 to the point it grenades itself because of forced induction.

BTW. Mine is only being run off tune lightly until the body is finished, then I can get to the workshop to fit the Lambda sensor and then it will be getting tuned correctly for the current build.

Belle427

8,863 posts

232 months

Wednesday 19th May 2021
quotequote all
drcarlos said:
I have these injectors fitted in my 400 along with some other fairly serious mods (Stage 3 heads, different cam, Stage 3 Intake package and a Megasquirt ECU system with wasted spark ignition) I am currently running it off tune when I drive it and it does jerk (massively on a trailing throttle) and overfuel, but it doesn't miss.
I put this down to the lack of Lambda sensor (prior to my acquisition it had a decat and sensor fitted but now I have a standard cat in place) and the car not being tuned for the way it's expecting to run.
I would expect that putting in larger injectors and pulsing them with the signal required for the older Lucas ones would have a severe impact on running and that your conversion to Emerald along with the requisite map will sort things out.
I learned a fair bit from modding my Impreza that every mod needs to be accounted for in a tune otherwise there are issues, the poor running you see in the RV8 is exponentially amplified in a BJ255 to the point it grenades itself because of forced induction.

BTW. Mine is only being run off tune lightly until the body is finished, then I can get to the workshop to fit the Lambda sensor and then it will be getting tuned correctly for the current build.
I'm almost sure that will be down to the fact the MS is looking for the lambda feedback to make its fine adjustments, I'm not sure what it does when it's not connected.

drcarlos

28 posts

191 months

Thursday 20th May 2021
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Belle427 said:
I'm almost sure that will be down to the fact the MS is looking for the lambda feedback to make its fine adjustments, I'm not sure what it does when it's not connected.
I agree, no way it can run correctly without the required inputs. It's pretty far from the way that the fellas above is but it was certainly showing a few of those traits the few times I drove it. Once we get the paint done (and it's pretty close, front end and bonnet done, just rear quarter and engine bay left now) I'll be driving it to the workshop to have the tyres swapped and we'll weld in the bung for the Lambda (I did attempt to get the Y off on the drive but the exhaust looks like it has to come off to get it off, so ramps and a second pair of hands needed).

spitfire4v8

3,990 posts

180 months

Thursday 20th May 2021
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combine04 said:
Back home, checked the plugs and all were black, showing over fuelling. Cleaned the plugs up, drove it 5 miles, issue returned. Unfortunately I don't have a Windows laptop, so cannot run Rover Gauge.
Sounds like you have other issues going on here to be honest .. there's no way a minor increase in flow of some 5 percent over the std injectors is going to give these issues.

I think I will be sending your new injectors away for flow testing to make sure they're what they say they are in terms of flow rates.

I put this in my emerald fact sheet that i send out to people because most people will rarely notice any difference in performance or drivability:

"In my experience the effect of changing injectors has previously been vastly over emphasised"





Belle427

8,863 posts

232 months

Thursday 20th May 2021
quotequote all
drcarlos said:
Belle427 said:
I'm almost sure that will be down to the fact the MS is looking for the lambda feedback to make its fine adjustments, I'm not sure what it does when it's not connected.
I agree, no way it can run correctly without the required inputs. It's pretty far from the way that the fellas above is but it was certainly showing a few of those traits the few times I drove it. Once we get the paint done (and it's pretty close, front end and bonnet done, just rear quarter and engine bay left now) I'll be driving it to the workshop to have the tyres swapped and we'll weld in the bung for the Lambda (I did attempt to get the Y off on the drive but the exhaust looks like it has to come off to get it off, so ramps and a second pair of hands needed).
No need to remove the exhaust, just loosen the y piece to exhaust clamp at the bottom and remove the 2 band clamps up top.
It then slides out from above.

Classic Chim

12,424 posts

148 months

Thursday 20th May 2021
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Belle427 said:
No need to remove the exhaust, just loosen the y piece to exhaust clamp at the bottom and remove the 2 band clamps up top.
It then slides out from above.
^^^^^^ this.
It might take quite a wiggle to break the seal between the exhaust and Y piece if it’s been on there a long time and I have to undo my exhaust clamp from underneath due to its positioning so give it a good shake there once the two bands clamps are off. Once it starts moving forwards a tad you have more room to wiggle it out from the top.
If it’s really tight some WD40 or similar at the exhaust clamp helps. Soon burns off later.


drcarlos

28 posts

191 months

Thursday 20th May 2021
quotequote all
Belle427 said:
No need to remove the exhaust, just loosen the y piece to exhaust clamp at the bottom and remove the 2 band clamps up top.
It then slides out from above.
I read that most came out like this so I did try, got it all moving easily then the cat bashed into the front chassis rail with a couple of cm of downpipe still stuck in the main exhaust and I couldn't see it being able to pass. So I bolted it all back up and thought i'd leave it for a workshop day (I basically have ramp access at my mates garage and either him or his other guy will help me out for a drink) as I have to go there to get the tyres fitted anyway.

spitfire4v8

3,990 posts

180 months

Thursday 20th May 2021
quotequote all
Yes you can normally get the slimmer decat pipes out, but the tvr cat is bulky and I *think* the only times i've been able to get one out without removing the exhaust is if you have a 500 with the front flexi pipe which allows some movement of the very first section of the exhaust system. Even then it's often easier just to undo the antiroll bar chassis mounts (but leave it attached to the wishbones) then unbolt the exhaust and slide it back (you can leave it then resting on the ARB to save you having to remove the bulky system if you're on your own)

combine04

71 posts

126 months

Thursday 20th May 2021
quotequote all
drcarlos said:
I have these injectors fitted in my 400 along with some other fairly serious mods (Stage 3 heads, different cam, Stage 3 Intake package and a Megasquirt ECU system with wasted spark ignition) I am currently running it off tune when I drive it and it does jerk (massively on a trailing throttle) and overfuel, but it doesn't miss.
I put this down to the lack of Lambda sensor (prior to my acquisition it had a decat and sensor fitted but now I have a standard cat in place) and the car not being tuned for the way it's expecting to run.
I would expect that putting in larger injectors and pulsing them with the signal required for the older Lucas ones would have a severe impact on running and that your conversion to Emerald along with the requisite map will sort things out.
I learned a fair bit from modding my Impreza that every mod needs to be accounted for in a tune otherwise there are issues, the poor running you see in the RV8 is exponentially amplified in a BJ255 to the point it grenades itself because of forced induction.

BTW. Mine is only being run off tune lightly until the body is finished, then I can get to the workshop to fit the Lambda sensor and then it will be getting tuned correctly for the current build.
Thanks for this - always good to have the conversation and learn!

Interesting that the car now runs OK, having adjusted the AFM. Car ran fine prior to adding the injectors too and cannot see how the decat would affect the fuel mixture? But more than happy to learn!

Also interested that the (very well know v8 builder) had seen/heard similar stories, when changing to these new spray pattern Bosch injectors.

drcarlos

28 posts

191 months

Thursday 20th May 2021
quotequote all
spitfire4v8 said:
Yes you can normally get the slimmer decat pipes out, but the tvr cat is bulky and I *think* the only times i've been able to get one out without removing the exhaust is if you have a 500 with the front flexi pipe which allows some movement of the very first section of the exhaust system. Even then it's often easier just to undo the antiroll bar chassis mounts (but leave it attached to the wishbones) then unbolt the exhaust and slide it back (you can leave it then resting on the ARB to save you having to remove the bulky system if you're on your own)
Full disclosure, I have Belle427's old car that I'm putting back together after it's armco altercation, so he should know what does and doesn't work on it (I'm still learning it's foibles). It could be that if I was a bit more forceful with it I maybe be able to twist it up and out without the removal of the rest of the exhaust, I was being fairly careful though. Anyway my mates welder (along with him being more skilled at welding too) is a bit nicer than mine so it's another good reason to take it there, it's not as if it's undriveable at the moment it just needs finessing a bit.

combine04

71 posts

126 months

Thursday 20th May 2021
quotequote all
spitfire4v8 said:
Sounds like you have other issues going on here to be honest .. there's no way a minor increase in flow of some 5 percent over the std injectors is going to give these issues.

I think I will be sending your new injectors away for flow testing to make sure they're what they say they are in terms of flow rates.

I put this in my emerald fact sheet that i send out to people because most people will rarely notice any difference in performance or drivability:

"In my experience the effect of changing injectors has previously been vastly over emphasised"
I'd be intrigued again to understand what it could be. Yes, the car runs a decat now but there has been no overfuelling issues on the old injectors and it ran fine in the previous 6 years of the previous ownership. Injector change, (brand new) plugs go black and cause a misfire. Clean the plugs, runs great for a few miles then cokes up again. Having adjusted the AFM, it now runs fine (but yes, as has been said, needs to be tuned to take into account the modifications).

davep

1,141 posts

283 months

Thursday 20th May 2021
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combine04 said:
I'd be intrigued again to understand what it could be. Yes, the car runs a decat now but there has been no overfuelling issues on the old injectors and it ran fine in the previous 6 years of the previous ownership. Injector change, (brand new) plugs go black and cause a misfire. Clean the plugs, runs great for a few miles then cokes up again. Having adjusted the AFM, it now runs fine (but yes, as has been said, needs to be tuned to take into account the modifications).
Running a set of injectors originally designed for use in a 6 cylinder, sequential, Motronic application on an 8 cylinder, batch fired, 14CUX multipoint system requiring two squirts per inlet valve opening not one, may have something to do with it. Couple this with not making any attempt to adjust for dead time, latency, main voltage compensation, etc, let alone the fuel map and you probably have a running lean situation causing over-fuelling as the ECU attempts to compensate.

How did you adjust the AFM?

spitfire4v8

3,990 posts

180 months

Thursday 20th May 2021
quotequote all
Under the same pulse test conditions that the injector test machines use flow rate is flow rate .. these new injectors must be something like i don't know say 50percent more flow for you to outstrip the ecu fuel trimming and still have a rich enough mixture to foul the plugs. the black smoke out of the back should be very apparent .. but the fact you can adjust the afm and make a mixture change suggests you're not on a cat/lambda map anyway ? But you should be on a cat protection map if you still have the precats in, they will be useless / overheating / collapsing with such unsuitable mixtures.

any road up there's something very wrong with what you have there.

Are people actually buying the correct injectors ? Has some odd info been published ? are there different flow rates of the same part number ?

My advice is (unless you have a good reason to change) leave well alone. The last thing a standard 4litre needs is more injector anyway.

davep

1,141 posts

283 months

Thursday 20th May 2021
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spitfire4v8 said:
Under the same pulse test conditions that the injector test machines use flow rate is flow rate ..
Joolz, just out of interest, have you tested the flow rate of the 045s dynamically and static? I'd be interested to see the comparison results of the dynamic testing of the OEM Lucas against the Bosch 045s.

spitfire4v8

3,990 posts

180 months

Thursday 20th May 2021
quotequote all
Never done it, I don't have my own injector test/clean machine I've always sent them away or bought from MrInjector or Injectortune who are both excellent. Maybe I should buy my own machine but really for the price those guys charge it'd be decades before i'd get my money back!

combine04

71 posts

126 months

Thursday 20th May 2021
quotequote all
davep said:
Running a set of injectors originally designed for use in a 6 cylinder, sequential, Motronic application on an 8 cylinder, batch fired, 14CUX multipoint system requiring two squirts per inlet valve opening not one, may have something to do with it. Couple this with not making any attempt to adjust for dead time, latency, main voltage compensation, etc, let alone the fuel map and you probably have a running lean situation causing over-fuelling as the ECU attempts to compensate.

How did you adjust the AFM?
Thanks Dave. This concerns me and sounds like I perhaps need to look at removing and reverting to either originals or the Vectra injectors?

My presumption here has been following the comments in the OP, i.e. better spray pattern for efficiency could only be a good thing for the old engine, as long as flow rates and fit are accounted for. To the point made above, 5% increase in flow rate resulting in overfuelling does sound strange (based on basic common sense here, not mechanical knowledge).

I have been informed there is a adjustment screw on the AFM.

combine04

71 posts

126 months

Thursday 20th May 2021
quotequote all
OK gents, good timing for my visit to Joolz for the Emerald anyway (good to speak to you - always a pleasure sir, see you soon). Will report back (or rather, Joolz will!!) with flow results.

davep

1,141 posts

283 months

Thursday 20th May 2021
quotequote all
combine04 said:
Thanks Dave. This concerns me and sounds like I perhaps need to look at removing and reverting to either originals or the Vectra injectors?

My presumption here has been following the comments in the OP, i.e. better spray pattern for efficiency could only be a good thing for the old engine, as long as flow rates and fit are accounted for. To the point made above, 5% increase in flow rate resulting in overfuelling does sound strange (based on basic common sense here, not mechanical knowledge).

I have been informed there is a adjustment screw on the AFM.
The adjustment screw on the AFM is for adjusting the CO Trim voltage and only has an effect on TVR ECUs running Fuel Map 2, i.e. precat Griffs. Your car should be running on Fuel Map 5 if it is set up for Closed Loop fuelling, i.e. Lambda sensors fitted and connected. So I assume you are running Fuel Map 2, which is known for being fuel rich. I think you do need to verify which fuel map you are running, open or closed loop, before swapping anything else!

combine04

71 posts

126 months

Friday 21st May 2021
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davep said:
The adjustment screw on the AFM is for adjusting the CO Trim voltage and only has an effect on TVR ECUs running Fuel Map 2, i.e. precat Griffs. Your car should be running on Fuel Map 5 if it is set up for Closed Loop fuelling, i.e. Lambda sensors fitted and connected. So I assume you are running Fuel Map 2, which is known for being fuel rich. I think you do need to verify which fuel map you are running, open or closed loop, before swapping anything else!
Valuable advice, Dave - thank you. I sadly can't check due to only "running" Macs at the moment, so cannot access Rover Gauge. However, pleased that timing is such that I'll be up to Joolz very soon for him to a/ check the car over including the injectors and b/ fit an Emerald with all mods and parameters taken into account!