Blue sender changed, throttle changed, still hesitant

[Rustynuts 0]

Water temps on the move don't even register on the guage, oil temps about 88 on the motorway. This is about 10 degrees down on what I would expect.

 

Anyway when in traffic it rises up to the 90 mark and fans kick in. I have read the VR cooling guide and suspect that the thermostat is stuck open.

 

I also have hesitation, it seems to be flat between 3500 and 4500 rpm, after that it goes beserk! I am guessing that the cool running is not helping things and that it is running in warm up mode. However, having sat to let it warm up and then see if the hesitation clears, it does not suggesting something else (I guess MAF).

 

Has anyone experienced this combination of issues before, or can shed some light?

[hodaz 0]

Had a similar problem with mine. Previous owner fitted a one of those low temp thermostats (presumably to mask an over heating problem that was wiring related which is now fixed) and car always stayed in "cold mode" meaning the temp would barely even register on the dash and the car would run rich - hence the increased performance when driving hard, but lumpy running when idling and normal town driving. Sounds to me like thermostat as you say. MAF problems usually present themselves as bad idle/stalling so I dont think thats a problem.

[CazzaVR 0]

I'd go with stat first too. Prob worth changing the blue temp sensor too- only a tenner from Ford, literally takes a couple of minutes to change. Unplug the sensors in the stat housing. Prise off the wire holder from above them. Just pull the old one out, stuff a rag in the hole, get new one ready to go in (remember a new o-ring), remove rag and quickly put the new sensor in. Top up any lost coolant- shouldn't be much at all if you're quick. Remember to only do this when the engine's cold ;) .

[Rustynuts 0]

Cheers for the advise, yeah done a Golf VR stat, quite easy to get to in terms of location, quite a fiddle to get at the allan key bolts.

 

Will pick up a stat at the weekend.

 

Idle is quite good, not lumpy and generally smooth, so maybe not the MAF

[Rustynuts 0]

Right well car now runs to temp.

But still got hesitation: I am suspecting that the TPS is suspect as it basically gets confused. Sometimes goes likes a bastard, but seems slow to respond to open throttle.

 

So far last owner swapped:

Fuel pump and filter

Lambda

MAF

leads, plugs, cap and rotor arm

 

I have swapped:

 

Blue sender

 

Next plan is to swap the throttle body and TPS.

 

I will also check earth connections in engine bay.

 

Failing this it could only be FPR and coil.

 

I figure it can't be timing because I don't really get a consistant hesitancy, when driving on part throttle and then booting it, car will respond slowly but will go eventually. Whilst going up gears though having finally got a response it will fly. I also get a little bit of low end rev judder. All this makes me conclude the TPS.

 

Ah well - one on order so will soon see.

[Rustynuts 0]

Right, well I needed to change the throttle, that was clear as the TPS was cracked and I also found that the original was missing it's throttle spring loaded return stop was missing.

 

The result, well a car that does not occasionally hunt, any low end judder has also gone.

 

However,

 

It still hesitates a bit on acceleration, so there is something else still to do. Off to see a mate on Sunday that has a whole ruck of OBD1 gear for sale so hopefully some of the simple swap stuff will sort it.

 

Going to try the FPR, another MAF, and even an ECU.

 

Must check the earths though, still not done that.

[buttles 0]

Funny, just had my FPR go on me. Luckily managed to get car home. Had a spare and was second thing I checked. Thank god for simple and cheap fix. The car is charged so don't know if diaphragm likes vacuum and pressure cycles too much? It was a Chinese made one that came with the Vortech. VW one back in now so fingers crossed.

[Rustynuts 0]

Still got to do my FPR, but did do the MAF, no difference.

 

This time of year is so pants, when I get home it is to dark, cold or wet to do anything.

 

Anyway off to a mates garage tomorrow where VAGCOM comes into play

[millerman 0]

just read all this and i was gonna say have you vagcom'd it :D so you have not changed your plugs or leads ??

FPR is doffo the next step i would have taken but it does sound like its running rich

will be interesting to hear what vagcom has to say :gag:

[hombre_paulo 0]

If you havent done so yet I would check your coilpack. I had a similar problem in the run up to winter, tried all sorts to get it fixed. Had to change the thermostat last weekend and when taking off the coilpack noticed a few sizeable cracks and a massive portion of rust. I stuck a new coilpack on this morning (ebay job) and she runs like a dream again. It is worth checking as it so easy to take off.

[Rustynuts 0]

It is a dizzy model.

 

VAGCOM:

 

Camshaft Position (Hall) Sensor - Open or short to plus

Engine Coolant Sensor - Implausible signal - intermittant

Oxygen (Lambda) Sensor - No signal - intermittant

Engine speed sensor - No signal

 

OK, well the lambda sensor is new, had 3 different blue sensors on the car with the same result. How the hell is the car running without a crank sensor signal?

 

Anyway, changed the ECU 021 906 258 B for an exact replacement off an early Golf VR6. No different.

 

So have I got the wrong ECU on the car, ie should it have originally been a B coded ECU? Or have I got a problem with the wiring as blue senders and lambda suggests I have.

[Rustynuts 0]

Correction, ECU replacement came off a Corrado

[buttles 0]

Change 1 and 2. Fix wireing to 3 and ignore 4. (assuming engine not running durind test) Camshaft sensor will cause very poor running if duff. On Number three sensor now. Have you retested after clearing codes?

[Rustynuts 0]

Change 1 and 2. Fix wireing to 3 and ignore 4. (assuming engine not running durind test) Camshaft sensor will cause very poor running if duff. On Number three sensor now. Have you retested after clearing codes?

 

Blue senders were changed, fault codes cleared, run and then checked. I wil say that all of them were old senders and at least 2 were GSF ones.

 

Thanks for your help.