No start after Injector swap Bosch 0 280 156 045 HELP!

[StuVT]

Hi all,
I decided to bite the bullet and install the Bosch 4 hole injectors as recommended on the injector thread on here, but I have major problems and the car is blocking my other car in the garage so not ideal.

I've just fitted these injectors and now it massively over fuels and will only start from cold for 30 seconds then dies. It will start with my foot on the floor but will only just idle at WOT. Eventually it'll sluggishly start to rev and then pick up and rev quickly but won't idle and then won't restart. It seems if I remove stepper and leave it open to atmosphere, open the idle screw all the way out it will just about maintain an idle but isnt happy and the garage stinks of unburnt fuel. So I think I've narrowed it down to not enough air

Stepper is working, I even bought a new one from Land Rover, has a nice fat spark from the king lead and again at the plugs, fuel pumps priming and runs when the engine is running. No codes in Rover Gauge. TPS range is 10% to 97%, no leaks that I can find. Occasionally after a session trying to get it to work I get a code 'lambda out of trim' which I assume is due to flooding. When its cranking the injector duty is 2% to 4% and when I finally get it to catch the duty cycle increases as it revs.

Summary - Original 14CUX ECU, main cat, no pre-cats and running fine before the work (yes I know if it ant broke....)
Changed injectors, added plenum spacer and sealed correctly, no air leaks
Will only fire up from cold off the key and wont rev just dies when peddle pressed
After its initial cold start it will eventually fire at wide open throttle and nearly 30 seconds of cranking
Idles only at wide open throttle, can gently close throttle but wont idle.
Once idle at full throttle the revs sluggishly start to come up until about 3k rpm when it revs a bit quicker. Garage full of fumes, no idle cuts
out.
TPS 10% closed and 97% open
Stepper new but new and original both work the same way.
After a while of trying stepper stops adjusting and sits at 37% - 40%. ECU confused with rich mixture?

Here's a vid, you can see the tps at 97% as the throttle is wide open and its idling at around 1000rpm. I've never yet been beaten by a problem on a car but this one is looking to be the 1st. Either TVR specialist and many many £££'s or I sell as is at an incredible loss.



And one with the MAF set to Direct

Edited by StuVT on Friday 26th February 12:27

[hoofa]

Have you checked the maf ? For correct reading

[Italian450]

Did you try unplugging the MAF ?

[EddyP]

From what you describe I think it might actually be under fuelling. It starts on the cold start, where there'll be more cold start enrichment so more fuel. Not sure what the TVR map is but often this will tail off as the RPM increases hence it dying as you increase the throttle.
Any chance you got the injector wiring mixed up and have the wrong wiring connected to the wrong cylinder?

[blitzracing]

This is a bit unknown territory readings wise, as you have the throttle wide open at idle speeds- but Id say when the fuel cells are at the top row, its in the correct position for idle, but I cant account for the map jumping to the bottom row with no change in AFM output plus this is not changing the injector pulse width. The AFM reading is way too high for idle airflow, but as you have the throttle wide open just to get it to run its not a valid condition anyway. Can some one do a quick check with RoverGauge for the injector pulse width at idle on a running car? (Mines winterised at the moment) to check this is in the ballpark? If it is then id say on the surface the ECU is doing what it should- so two steps backwards time--- Drop is plug out, is it soaking with fuel? Double check your part numbers- are you 100% sure they are the correct injectors? Also check you dont have a collapsed pipe to the AFM, its quite common and causes some really odd readings.

Another thought- make sure you have not pinched the fuel return line from the regulator in some way, as this causes a massive boost in fuel pressure that will cause severe over fuelling.

Edited by blitzracing on Friday 5th March 10:01

[spitfire4v8]

If youve changed something and now it runs badly, and you can't figure out why, surely the most logical thing to do is put it back to how it was originally and see if the fault remains or goes away. Until youve eliminated the new parts as faulty stop looking for faults elsewhere. if it still runs like poo after you swap back then you know it's you that's introduced the fault. If it runs fine on the old injectors you've found your problem.

In my workshop I would never fit a part, find out the engines barely runs, and go looking for faults elsewhere .. I'd always go back to the original part (if possible) to eliminate it from the investigation.

[combine04]

Interesting thread, sorry for the bump and revival.

I installed the new injectors at the same time as decat'ing (Clive F Y piece and pre cat removal). I'm massively overfueling and this is causing a misfire as my plugs are fouled up. When out for a blast recently, having cleaning the carbon off the plugs, it was fine, then misfired, then cleared. As soon as I slowed in traffic it fouled up again leading to a misfire.

Hoping it's a case of MAF misreading, but it's going into Joolz at Kits and Classics soon anyway...

[davep]

Sequential injector deadtimes compared with OEM batch and the values set in 14CUX maybe? IOW wrong injector for the application, 4 squirts per cycle not two.

[blitzracing]

Interesting point- I don't know how much the open and close time vary between injector types. If the injector opens faster it will have a much greater effect given a set pulse width at a small opening time like idle . Mind you his symptoms are so bad this is not a just +/- 10% fuelling error.

[davep]

Wide open throttle, 0 road speed and RPM stuck low is going to send the ECU into a frantic search for fault conditions while attempting acceleration enrichment. Plus the TPS sense routine blocks the incoming spark related fuellng interrupt while error checking, etc. Hence the erratic fuel cell movement.

blitzracing said:

Interesting point- I don't know how much the open and close time vary between injector types.

The only people that really know that are injector designers and manufacturers i.e. Bosch. And they aren't going to tell you any time soon.

Just a thought, if you are into 4 hole injector nozzles and keeping 14CUX then perhaps these would be a better choice than 045s, which were specifically designed for a 6 cylinder sequential FI and Motronic 2.8 EMS application:

https://www.fiveomotorsport.com/lucas-range-rover-...

Edited by davep on Tuesday 9th March 13:13