Reply With QuoteEFI temperature sender I believe. It should read around 300 ohms when hot. I lives under a 2 wire plug at the front of the inlet manifold, near the thermostat. If it is open circuit it causes the ECU to read "full choke needed".
Master
SupporterMy RR87 is misbehaving again, started to run very poorly and sounded as though it was misfiring. crawled home last night and replaced all plugs and leads and no change. swapped out coil no change. All plugs were blackened so running too rich.
Firstly how do you alter the mixture to make it run leaner?
Secondly, What else could be causing the poor engine running? I played around with the dissy location timing and that may little change as well so you get an indication of how badly its running.
Only thing I can come down to is the dissy cap although I wouldn't know a good one from a bad one unless it was cracked and obvious.
Any ideas would be greatly appreciated.
AT REST
EFI temperature sender I believe. It should read around 300 ohms when hot. I lives under a 2 wire plug at the front of the inlet manifold, near the thermostat. If it is open circuit it causes the ECU to read "full choke needed".
Master
SupporterThanks for the response bee utey, would this cause these symptoms as it sounds like it is only running on two cylinders, has no power idles at almost 300rpm but all over the place and lucky it doesnt stall. If its the temp sensor wouldnt it behave when cold as now cold or hot the car runs the same.
AT REST
Probably something different. I once had the privilege of doing a major fix on an '87 using the factory workshop manual, there were a lot of things that could go wrong. Can't remember all of them now.Originally Posted by PeterAllen
The main thing I would check for now is the fuel pressure regulator. It has a small vacuum hose connected to the manifold somewhere near the back. Pull this hose off and look for signs of fuel coming out. If there is any your regulator has failed and you need another one. I did one on a Falcon a few weeks ago that sounded much like yours.
Master
SupporterAre you refering to the little vacuum hose that attaches to the rear of the plenum chamber ?
AT REST
Yup.
Master
SupporterOk thanks for that, I will check that out.
Thanks for your help and knowledge
Master
SupporterPulled the hose off at back of Plenum chamber and no fuel. By the way should this be done with the motor running?
I looked with engine off and now battery is dead so will have to charge it before checking further. I will also check where hose attaches to regulator although that is a bugger to see anything down there.
Master
SupporterFurther to this have found no fuel at vacuum hose of regulator. All plugs and leads are working. Drained fuel and changed fuel filter. Ran high octane with repco injector cleaner and no real change other than can rev engine up a bit more and have flames coming out the exhaust when backing off. V8 super car looks but no action. Some black smoke coming out of exhaust as well on occassions. Seems to be eating the fuel like there is no tomorrow just sitting and testing but no visiable leaks anywhere. Noticed some plugs while testing were arcing from the side of the plug electrode rather than across the gap could this be a problem? All sparks were good.
Any thoughts on what to check out next as am running out of choices and dreading to visit the experts given current cash situ.
Wizard
SupporterG`day ,
Without seeing it , i`d say your right thinking it`s not an ignition problem because of the plug colours you replaced .
These are things that will cause rich no matter if hot or cold temps .
The fuel reg really needs a gauge on it to check pressure as the vacuum limits the pressure but if the pressure was to high overall it could run rich . Static pressure test would also show an internal injector leak ETC .
...............
Pressume you`ve checked the aircleaner and intake are are clear and the plasic pipe isn`t being sucked flat ETC .
The potentiometer in the airflow meter tell the injectors how long to stay open and if faulty can cause a rich running engine , can be checked with meter but easier to swap a known working unit .
There is another potentiometer linked to the butterfly (TPS ) it also tells the ECU how long the injectors should stay open and if not right can also cause rich running .
The crankcase vent system has an influence on how much air is inside the system and can cause rich running .
Check the filter on top of the rocker cover , check the pipe works not blocked , there is a passge inside the butterfly snout on inlet top cover that blocks on these flapper 3.5s needs a welch plug removed and the hole cleaned of carbon with a drill bit .
If the cold start injector has a major malfunction it could cause rich running but is pretty unlikely beacause of how it works . It may be worth disconnecting it to be sure , mostly the fuel side .
Most other things no working right like the actual cold start extra air bypass , should only be a problem when cold as it has no effect when hot .
One other thing that these models do is the ECU solder dry joints and can cause them to run as yours , though normally there will be some intermittance and some time they will run clean for a short time by gently tapping the ECU body .
As you can see there are lots of roads to take and elimination will solve your problem just may take awhile .
If you need specifics i`d need to look and i`m sure there are more causes than i remember .
Peter
Posting Permissions
| Search AULRO.com ONLY! |
Search All the Web! |
|---|
|
|
|
Bookmarks