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-   -   1.8 Turbo hesitation/stutter under full throttle (https://www.the75andztclub.co.uk/forum/showthread.php?t=305663)

JOHNDQ 18th June 2020 12:07

Quote:

Originally Posted by Mean & Green (Post 2819556)
Managed to find out for certain mine is over boosting, so not an ignition issue.

Plug wiring on my MAP sensor looks badly damaged. Going to swap the plug harness out and take it from there.

I not looked at mine to be honest yet but it's got the K Maps tune on it so not exactly sure what the maximum boost pressure should be

Mean & Green 18th June 2020 15:15

Quote:

Originally Posted by Ravinder (Post 2819560)
I remember you from the detailing world forum. Your ZR is lovely. Great you still have it.
What was the issue with the turbo then?

Thanks for the compliment on the ZR, yep still got it. Can’t part with it after this length of time. If you see my last post above yours it explains the current status with my turbo. :}

Quote:

Originally Posted by JOHNDQ (Post 2819603)
I not looked at mine to be honest yet but it's got the K Maps tune on it so not exactly sure what the maximum boost pressure should be

I wouldn’t know what the boost is supposed to be, to be honest. It was MarinaBrain who plugged his computer in and did a full diagnostics and viewed the cars data. He knows more a lot more than me on this subject, top bloke.

JOHNDQ 20th June 2020 15:08

Sorted mine swapped the 400 mile old denso plugs for a set of NGK iridium's. That's the 2nd set of Denso's I've had this problem with now other was on my ZS, again problem starting after a few hundred miles

Mean & Green 20th June 2020 18:15

Quote:

Originally Posted by JOHNDQ (Post 2820063)
Sorted mine swapped the 400 mile old denso plugs for a set of NGK iridium's. That's the 2nd set of Denso's I've had this problem with now other was on my ZS, again problem starting after a few hundred miles

I wish mine was as simple. Got myself a replacement wiring harness, just need to get some heat shrink from work so I can replace this...

https://www.the75andztclub.co.uk/for...e50ee86875.jpg

That can’t be doing it any favours. Hopefully when I’ve soldered the replacement in the issue will be resolved, but knowing my luck it probably won’t be as simple as that.

JOHNDQ 21st June 2020 08:41

Quote:

Originally Posted by Mean & Green (Post 2820088)
I wish mine was as simple. Got myself a replacement wiring harness, just need to get some heat shrink from work so I can replace this...

https://www.the75andztclub.co.uk/for...e50ee86875.jpg

That can’t be doing it any favours. Hopefully when I’ve soldered the replacement in the issue will be resolved, but knowing my luck it probably won’t be as simple as that.

Hate tho Delphi connectors the terminals pull backwards into the plug rather than slide into amount of times I've crimped on the terminals when replacing the multi plug and realised I haven't put the plug on wires first :duh:

Mean & Green 22nd June 2020 08:19

Quote:

Originally Posted by JOHNDQ (Post 2820178)
Hate tho Delphi connectors the terminals pull backwards into the plug rather than slide into amount of times I've crimped on the terminals when replacing the multi plug and realised I haven't put the plug on wires first :duh:

I’m just going to cut off the old plug and solder sleeve the replacement in line with the existing harness. Then heat shrink it up for neatness. I don’t have access to the correct crimp tool for these pins.

Mean & Green 28th June 2020 09:56

MAP sensor wiring replaced and it’s made absolutely no difference at all.

Car still judders on full throttle.

So far that’s new plugs at 0.6mm, new boost solenoid, damaged MAP plug wiring replaced.

I can only assume it must be a wastegate issue. The thing is I can hear it dumping at low revs, so don’t really understand how it’s over boosting.

I’ll investigate the wastegate actuator next as apparently they can seize, anyone got any photos of the actual actuator? Haynes isn’t any use whatsoever.

COLVERT 28th June 2020 13:53

Quote:

Originally Posted by Mean & Green (Post 2821578)
MAP sensor wiring replaced and it’s made absolutely no difference at all.

Car still judders on full throttle.

So far that’s new plugs at 0.6mm, new boost solenoid, damaged MAP plug wiring replaced.

I can only assume it must be a wastegate issue. The thing is I can hear it dumping at low revs, so don’t really understand how it’s over boosting.

I’ll investigate the wastegate actuator next as apparently they can seize, anyone got any photos of the actual actuator? Haynes isn’t any use whatsoever.

https://itstillruns.com/signs-symptoms-faulty-wastegate-8611638.html











:shrug:---Haynes.--4C.9---Pic, 17.12

Mean & Green 28th June 2020 15:35

I’ve managed to use a bicycle pump on the boost solenoid actuator using the cars existing tubing. It appears to be moving freely, so it mustn’t be a fault with that.

I can’t understand what’s causing this overboost issue. I’m becoming quite frustrated with it now.

COLVERT 28th June 2020 17:12

Quote:

Originally Posted by Mean & Green (Post 2821642)
I’ve managed to use a bicycle pump on the boost solenoid actuator using the cars existing tubing. It appears to be moving freely, so it mustn’t be a fault with that.

I can’t understand what’s causing this overboost issue. I’m becoming quite frustrated with it now.

I believe under certain circumstances it can possibly BOUNCE . ( And cause hesitation. )


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