280i running problems..
Discussion
1982 280i Have changed fuel filter, had to do it twice, Eventually stopped leaking,Starts and ticks over but when you accelerate it sounds like its starving fuel or lacking power.. Am going to change plugs, air filter, leads, rotor arm, distributor cap.. The fuel distributor cover has a small hole where pipe fits, Have blocked it but no different..ok if little bit o throttle.. more throttle and it sounds like a twin webber.. You know that burrr noise, I had something similar on a v6 toyota and that was head gasket.. Im hoping its not because i bought the car with an mot and it said driveable in ad.. any appreciated.. Thanks
Will it keep running on idle indefinately or does it die? If it dies it sounds like you might have an issue with the fuel pump wiring or run start relay. Can you give some more info like when it did run good, how long it has been since then, is it fairly stock or b
died wiring? Everything else working okay. This hole you describe, what goes there?
died wiring? Everything else working okay. This hole you describe, what goes there?I had it running for about half hour and did tick over although it was 1500rpm,I wouldnt say that it was eratic but isnt a totally smooth idle, Didnt show signs of wanting to die and on slight revs sounds great but when you rev it(standstill)harder thats when it sounds bad.. The wiring is a bit un tidy which i was gonna get it looked at but it starts, will try lifting plate and will pop on forum at mates this morn to let you know.. Cheers
Edited by mrzigazaga on Tuesday 20th July 09:25
mrzigazaga said:
started 280i.. put fingers in air box and lifted plate.. Car stalled.Could it be mixture.. Im really losing heart over this car.. Cheers guys..
Hang in there.Lifting the plate gives it more gas, that plate is lifted by airflow so the fact it stalled is not all bad at least you know it is having some effect:}
Next, put fingers under the plate and rev the car to make sure the plate is lifting by air flow, and not sticking
I'm not sure if you have knowledge of a CIS system, but basically mixture is fixed with regard to the Fuel disributor. It is more about flow (or pressure) The pump supplies a pressure which is them moderated by the WUR (warm up regulator) as air lifts the plate a needle vavle allows more flow to the fuel distributor and then the injectors. Which is proportional to the air flow.
While the car is cold the air is increased by AID (aux air device)activated by the thermotime switch
This can be ignored for now if it idles cold.
The pressure is adjusted with the pressure regulator, you should not adjust it (yet) but you could undo it and make sure it is clean. it is located on the front side of the Fuel distributor (horizontal), remove, clean, replace. It has shims, do not drop them, make sure they go back. The shims are used to adjust the system pressure.
To set up these cars it requires a CIS pressure guage, it is like a regular guage but has a "T" in it and a valve. So the system and control pressures can both be measured.
One test that can be done w/o a gauge is a flow test. It will give a good indication that all is well from tank to WUR, it will also maybe clean out some cr@p or at least show condition of fuel after the new filter.
I'll write up smoe instructions for this test and post later.
PS
That little hole that was giving you some concern is the Fuel dist mixture, that is a factory setting, best left alone. That is a specialist adjustment.
ETA CIS has residual pressure so as with changing the filter checking the Pressure reg should be done COLD.
Edited by jeff m on Tuesday 20th July 15:03
cheers mate, That sounds pretty easy to do. Will give it a try when it has cooled.. The tamper proof seal is missing from the fuel distributor so i dont know what the last owner has done to it.. I just noticed today there is a small patch of wet oil under the car and the sump looks a bit wet... Im trying to hang in there.. Not literally.. Cheers
mrzigazaga said:
cheers mate, That sounds pretty easy to do. Will give it a try when it has cooled.. The tamper proof seal is missing from the fuel distributor ..
I think most are
mrzigazaga said:
I just noticed today there is a small patch of wet oil under the car and the sump looks a bit wet..
.Are you sure it isn't a Porsche OK Flow test, this proves quite a lot, 'cos if you get adequate flow then you WILL have decent pressure.
These cars only pump with the crank turning normally so you will have swap a relay so the fuel pump opertes by the key.
On the US cars it is a cream relay, swap it for any four pin relay. 74 or 79 will do.(under passenger footwell).
Next you have to select the return from the fuel distributor.
I just tried to take a photo so I could put an arrow but it would have been bonnet off.....so you will have to select it by process of elimination.
The flow goes...in order Fuel filter into the F.D. out to the WUR and back to F.D.. Similar one for the Frequency valve (emmissions if you have it) and back to F.D. six top ones to injectors and one to the cold start injector. It's the one you have left.
It also lines up with the inner of the pressure regulator if that is any help.
Sorry that is such a terrible description.
You should get 750 ccs in 30 seconds.
Get a glass jar pour in 750ccs of water measured from wifes kitchen mearsuring jug, make a paint mark on glass jar.
Lets hope it's clean.
PS
It is possible the safty relay already has a four pin relay in it. Listen for the fuel pump with just the key first, that will eliminate the need for relay swapping.
Edit if you don't get lifting on the sensor plate when booting it, skip the flow test and we'll adjust the sensor plate first.
Edited by jeff m on Tuesday 20th July 20:27
I'd also print out a CIS troubleshooting guide to see what all is working and what isn't like the cold start injector could be firing, warm up regulator and aux air valve. It is a simple system but it is also a PITA system. Be patient. I have mine running sans a computer, sans the cold start valve and sans the pressure regulator return relay (I think they were a US thing though). Like I said, it is a simple system much like a carb that you can make work despite other issues.
For the CIS trouble shooting guide do a search on yahoo. There is one for the Capri that is pretty good also a Porsche 928 write up.
For the CIS trouble shooting guide do a search on yahoo. There is one for the Capri that is pretty good also a Porsche 928 write up.
Jeff M explanation is nice and clear. I have scanned the Fuel Injection system from my TVR manual and have the troubleshooting guides. Send your email address to my profile and I will send you them and also the ignition guide. If anyone else wants them do likewise.
It could be that the Auxilary Air Device which allows extra air through when it's cold. Sits at the front of the left hand head (looking from the front) It can stick open so too much air goes in. When engine is warm squeeze the pipe closed and see if the tickover reduces. Use carb cleaner.
It could be that the Auxilary Air Device which allows extra air through when it's cold. Sits at the front of the left hand head (looking from the front) It can stick open so too much air goes in. When engine is warm squeeze the pipe closed and see if the tickover reduces. Use carb cleaner.
Edited by MJG280 on Tuesday 20th July 21:27
One other thing that I just thought of, check the intake hose and the rubber cap ontop of the fuel meter for any cracks or leaks. Take them off and check real good on the bottom too. That could be a culprit as well. If you see anything suspect you can use some nice duct tape to test it. While your at it check the other vacuum lines.
There is a reason why it is idling at 1500 as 6-700 should be a good number.
There is a reason why it is idling at 1500 as 6-700 should be a good number.
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