Will not idle: Increased resistance on primary coil

[alwigley]

Currently waiting on a working 'test' coil courtesy of Alasdair, although thanks to the usual efficiency of the Royal Mail who seem to play knock down ginger every time they deliver anything fractionally bigger than an envelope, it is currently residing at a sorting office somewhere near here....... will let you know. Just wanted to say thanks to all who replied with friendly & decent advice. Also managed to take a couple of photos at the weekend [] Tried to put it up as my profiile picture, but no idea if it will work.

 

[Mike_Pollock]

Hi Many years ago I used to have a Lancia HPE 2.0ie which had a similar Bosch injection system and a similar problem which was the fuel pressure regulator - totally confused me (easily) and the 15 year experience of my Lancia indie. So if the coil doesnt work - I'd look at the regulator! Good luck Mike

 

[peanut]

any luck getting the car to run Alan ? post back and let us know how you are getting on. I have some Bosch guides that might be useful .

 

[alwigley]

No useful progress at all, I'm afraid - swopped the coil for the spare from Alasdair and it made no difference, so there goes that theory ! I then decided to pull off one of the injector leads and start her up, at which point she will just about run without me touching the throttle, albeit hunting terribly at low revs. This might indicate that the fuel rail pressure is wrong, so it could well be the fuel pressure regulator, so I either need to get hold of a pressure guage, or ask someone else to take a look for me. Will figure something out this week and let you know the result. Had to get the train to work this morning......... good incentive to get her fixed !

 

[alwigley]

She starts & runs ! Replaced the fuel pressure regulator and damper with known good ones from Alasdair (thanks again !) and she fired up first time. Idle is still a little erratic, and almost dies when I raise the headlights, so I have some electrical testing to do, but I managed to drive her to work today for the first time in a good few weeks []. Needs a little bit of throttle before she will stabilise on startup, and seems to be running fairly rich, but I can live with that for the moment. Has anyone else experienced the idle being heavily effected by auxillary electrics ? Thanks for all the help.......

 

[peanut]

ORIGINAL: peanut

ORIGINAL: alwigley Have heard that the fuel pressure regulator on the end of the fuel rail can cause this sort of trouble, which can be proven by the simple expedient of disconnecting one of the injectors, so will have a shot at that this weekend.

you've got that the wrong way round. if the fuel pressure regulator FPR fails to relieve pressure your fuel system will over-pressurize . It is the overpressure that shuts down the ECU and shuts down the fuel pump and injector pulsing. If you disconnect one injector and the car then starts it indicates too much fuel pressure. You can buy a simple cheap fuel pressure gauge off ebay for £10.00 just connect it to the fuel rail with a bit of garden hose and some jubilee clips.

don't wish to crow but isn't that precisely what I suggested you do a week ago !?[] Glad to hear that you've got it running anyway. I would now suggest that you get your injectors cleaned and tested including your cold start injector if one is fitted. You've not run the car a while so the injector solenoids will be sticky and fuel delivery will be irratic until you've run the car for a couple of hundred miles or so

 

[alwigley]

You were dead right - just took me a while to get around to looking into it properly. After a few people started mentioning it as a fault, and Alasdair kindly offered to send me replacements I though it worth a shot - before then I had reached the point of giving it to someone else to sort out........

 

[peanut]

well done anyway. its satisfying to find a solution yourself. The car will start to run better once you've been on a few long runs. The hesitation is only likely to be the injectors sticking. Get some fresh fuel in the tank and it will soon be back to normal.[]

 

[alwigley]

Have put a load of injector cleaner in the tank in the hope that will tidy things up a little, and may pump some air intake cleaner through over the weekend just to make sure everything is nice and clean. Will also start to replace plugs/rotor arm etc. over the coming months as I am not sure how much servicing has actually been done since the engine was rebuilt 4yrs/10,000 miles ago - I suspect not a lot as the air filter was filthy ! Need to think about checking the belt tensions as well.......

 

[peanut]

ORIGINAL: alwigley Have put a load of injector cleaner in the tank in the hope that will tidy things up a little, and may pump some air intake cleaner through over the weekend just to make sure everything is nice and clean. Will also start to replace plugs/rotor arm etc. over the coming months as I am not sure how much servicing has actually been done since the engine was rebuilt 4yrs/10,000 miles ago - I suspect not a lot as the air filter was filthy ! Need to think about checking the belt tensions as well.......

good plan. may i suggest that you only ever replace one thing at a time and test the car before replacing another. That way if anything goes titsup you know what caused it.[]

 

[barks944]

When did it last have an oil/filter change. Can make a big difference if the oil is in a poor state.

 

[alwigley]

Have no idea - probably when the engine rebuild was done ! Nothing documented in the last couple of years, so am going to work my way through the usual service items as and when I have the time, and hopefully when I get to the end she will be running sweetly []

 

[alwigley]

Problem with the idle dropping drastically whenever any auxillary electrics turned on is fixed - turns out the DME temperature sensor was faulty. Have to confess this is not wholly my fix, but mostly the result of the RAC chap who mentioned that all of this type of fuel injection system have one 'main' sensor in the loop that can have this sort of effect. Pulled the lead off when running and the idle returned to normal All credit to Euro Car Parts in Crawley who actually had one in stock, which is pretty impressive for a sensor for a 27 year old car ! All I have to do now is get the idle down to 800rpm rather than the 1200rpm it is currently at when warm..........[]

 

[zcacogp]

Absolutely. One temperature sensor that gives a lot of information to the ECU about the engine. Or rather, the ECU bases a lot on the output of this sensor, and if it fails then a lot will go wrong. The sensor is common to a LOT of cars; the fitment list will be very long. ECP would be daft not to carry quite a number of them ... Oli.