Car Dying Under Load (Code P1200)

[RoadWarrior]

Hello all!

 

I've been searching away on the forum (and Google) and can't seem to find a definitive answer to the problem I'm having, so I'm wondering if anyone here can work it out.

 

For the past week I've been driving the car round and every time I try to accelerate it starts stuttering really badly (as though someone is slamming on the brakes). Accelerating gently has been ok, but it's like the car has the flu. I had a new fuel pump fitted in the summer and originally thought it was that, but today I've fitted an OBDeleven device and found error code P1200 (apparently the recirv valve). I've got a Split-R fitted and installed correctly with the right number of clicks... it's been on the car for around 5 years now.

 

Thing is, I've now cleared the code... which cut the engine out and now it won't start. It does try to start, but just as the engine is about to roar into life, it dies.

 

I've had a cursory check around the pipes and can't find any splits (mostly replaced by silicone and aluminium piping now anyway).

 

I just can't work it out - the car wants to start and get going, but something is stalling it.

 

 

Any help appreciated 

 

P.S. There were other codes found but they were silly things like oil sensors (missing due to shallow sump installed) so they aren't an issue.

[kentphil1]

P1200 primarily relates to the N249 boost control solenoid, with a secondary check of the diverter valve, but they are separate components that need checking.

 

http://wiki.ross-tech.com/wiki/index.php/17608/P1200/004608

 

Split r valves dont play well on vag stuff, but if it has been on for 5 years, that should not be the issue stopping it starting provided the valve has been serviced appropriately.

 

I would check your wiring connector to the n249 for damage or corrosion on the terminals, as a start, then try a substitute known good valve and go from there.

 

Hope it helps

 

 

Edited 8 January, 2021 by kentphil1

[RoadWarrior]

Ah ok that would make sense and explain why it was stuttering so much. 

 

Would that stop the car starting though? It was running before, but now it won't even fire... so possibly something else? 

[kentphil1]

It shouldn't, but if you have loom damage, it may be creating a short/noisy signal that is making the ECU move to a richer airflow mode. As it only takes 2 minutes to check the plug, it's a good place to start, especially as you already are recording error codes.

 

I take it that the battery has sufficient voltage?, as a failing battery will cause systems to selectively shut down and protect the ability for the car to try to run.

 

I notice you say you had other codes that you thought were unrelated, what were they?, as they may not be as unrelated as you think.

[RoadWarrior]

Ah... the battery did die when it was off the road from August to November. It recharged and has been fine, but maybe it's faulty. Might be worth a new one then, although it's only died the once and is only 2 years old. I've noticed the fuel pump isn't priming when I open the front door, so maybe that's a sign the battery is duff.

 

I didn't record the other codes, but they were nothing to do with the problems I'm having: [1] oil sensor missing due to shallow sump [2] central locking problem - not all doors lock when I press the internal lock button [3] air conditioning problem. I doubt any of those 3 would have anything to do with it as those problems have existed for years.

 

I've bought a new Forge 008 recirc valve just in case the Split-R is knackered (007p is no longer in production) and an N279 solenoid - both should be here in the next couple of days. When I go to fit the solenoid I'll have a look at the connections, etc.

 

Cheers for the help 

 

 

[RoadWarrior]

So, I've fitted the new recirc valve and a new Yuasa battery... I put the key in the ignition, the car fired into life and then immediately died. It's now throwing up a new code: P1602 - Power Supply Terminal 30 (low voltage).

 

I just don't understand why the car isn't starting up properly. It was turning over before (albeit very rough) but since I've cleared the original P1200 code, it just won't fire into life anymore.

 

 

[kentphil1]

The 1602 code is there because the battery leads were removed to change the battery.

 

You can clear that and it should not come back.

 

Have you checked all your fuses are intact?, in both the cabin fuse box, and the battery fuse box?.

 

It sounds like either the car immobiliser is trying to cut the car dead or your fuel pump is not fully priming.

 

Are you trying to start the car without using any throttle input?, if so, what happens if you use about 1/3 throttle?, does it rev and stay running or just die?

[kentphil1]

I just had a thought just now, do you have a spare fuel pump relay that you can try at all?.

 

If not, you could temporarily by pass the relay just to test if it is that or not.

 

 

[J.R.]

Immobiliser.

 

Do you have a second key to try?

Edited 13 January, 2021 by J.R.

[RoadWarrior]

On 12/01/2021 at 19:53, kentphil1 said:

The 1602 code is there because the battery leads were removed to change the battery.

 

You can clear that and it should not come back.

 

Have you checked all your fuses are intact?, in both the cabin fuse box, and the battery fuse box?.

 

It sounds like either the car immobiliser is trying to cut the car dead or your fuel pump is not fully priming.

 

Are you trying to start the car without using any throttle input?, if so, what happens if you use about 1/3 throttle?, does it rev and stay running or just die?

 

Ok so I've cleared that code and it's not come back. Today I've checked all the fuses (box and battery) and all of them appear fine.

 

If the issue is the fuel pump, would that not throw up a code? I've never messed around with fuelling and don't know where the relay is or how to bypass it - bit worried if I mess around with that I might do more damage 

 

 

On 13/01/2021 at 00:09, J.R. said:

Immobiliser.

 

Do you have a second key to try?

 

I did think that... but the immobiliser light only lights up briefly when the ignition is on (as with other lights) and disappears after a second or 2. If I try to start the car it stays off. I don't have a second key unfortunately.

[kentphil1]

The fuel pump relay is located in the relay panel that is accessed from the drivers footwell. Basically, if you put your head down by the pedals and look up after removing the felt trim panel there, you should see a panel with several relays on. Pump relay is marked 409

 

I have seen these relays fail without producing an error code, as they are really a high current switch to arm the pump. I only suggested temporarily bypassing the relay to try to avoid the expense of replacement items that you are unsure are the culprit. A bypass would run the pump all the time, but if the car starts and runs, then you know the relay is suspect, and you can remove the bypass and order a new relay. If it makes no noticeable difference, then the relay is not your problem.

 

As in all things, if you think you are out of your comfort zone with this, it may be time to call in a local specialist/auto electrician.

Edited 16 January, 2021 by kentphil1

[RoadWarrior]

[SOLVED] Posting this for anyone who has similar issues and arrives here from a forum / Google search!

 

Ok... so it turns out the issue was 2 things! The original issue was indeed the recirc valve - the old Split-R was knackered and not holding vacuum (hence the lumpy feeling when accelerating hard). Issue fixed with a new Forge 008 valve fitted.

 

I got the AA out to have a look at the car not starting and explained the fuel pump wasn't priming - the technician grabbed a hammer, whacked something underneath the car whilst I tried starting it and VRRROOOOOOM! So it turns out my 6-month-old "DeatschWerks DW65v High-Flow Fuel Pump" was a pile of crap and certainly not worth the £230 I paid for it! New OEM pump was put in by my step-brother mechanic and hey presto... car all good again.

 

Thanks for all your help Phil and J.R. - much appreciated 

 

 

For anyone thinking of getting the aforementioned fuel pump... AVOID!