- This topic has 38 replies, 6 voices, and was last updated 12 years, 8 months ago by
.
-
Topic
-
-
Replies
-
Welcome to the forums!
First off, does the vehicle has a check engine light on?
If you don’t have a scan tool that can view data PID’s, you can test the ECT by using a DVOM. As the coolant temperature increases, the resistance of the sensor should decrease or increase dependent on sensor design.
I would also be doing a injector leak down test too.
If you remove the spark plugs, do they smell fouled?
You could try a clear flood start which is cranking the engine over with the accelerator pedal depressed.
Hope this helps.
Thanks for the reply
No check engine light on, ran on board diagnostics on car and no fault whatsoever.
Tested the resistance of coolant tempiture switch and seems to be fine increases and decrease according to tempiture.
Now not too sure about the injector test i manually took each injector out and cleaned them and tested them with a 12volt batery and spray seems fine although
im no expert!!!! And would’nt have the proper tools just applying hand preasure to the injectors for the spray.
The engine will start first turn but very poorly running. Just barley ticking over untill it gets its barings and runs normal.
If you disconnect the fuel pressure regulator from the vacuum, and crank it, there shouldn’t be any fuel shooting out the vacuum port. If there is then you have a bad regulator causing fuel to fill the intake with fuel..Doesn’t hurt to check.
Just the fuel Regulator vacuum port disconnect ya i will do that and let you know how i get on. Maybe Dreamer was on about the injectors leaking aswell
that could be causeing the problem……
Quoted From bälon:
If you disconnect the fuel pressure regulator from the vacuum, and crank it, there shouldn’t be any fuel shooting out the vacuum port. If there is then you have a bad regulator causing fuel to fill the intake with fuel..Doesn’t hurt to check.
That is a good point. You can also run the vehicle without the vacuum hose attached as some FPR may take a minute or two to show signs of leakage as shown in this video –
http://www.youtube.com/user/ScannerDann … KtR_yF7bi8
Ok i have checked the fuel pressure regulator against the video that Dreamer has shown me thanks for the example too and ran the engine for 5 minutes
and no fuel came out. Apparently if i start the car when the coolant tempiture switch is telling the ECM of cold condition its starts first turn but rough
idle and then after 5 or 10 seconds runs fine and wont cut out. Every morning except during the summer when the weather is warm in the mornings and starts up
fine. Thanks for the help so far its great. In the winter it wont start first turn due to freezing tempitures and usually takes a second turn of the key and rough idle
then 5 to 10 seconds cars runs fine………………….
I think that one might be old enough that it uses a ‘cold start injector’ meaning they have another fuel injector mounted in the intake to add more fuel during cold start up. This injector often runs on a separate circuit than the main injectors in that it has it’s own coolant temp switch and fuel supply. Sometimes the switch will fail and cause the injector to be on when it shouldn’t but I’ve also seen situations where the injector itself was leaking. Try looking at the intake plenum to see if you see anything that might resemble this part, it would have it’s own fuel line going to it.
It’s something to check for anyway.
Na this does not have a cold injector its the newer engine or its the 4AFE engines thats more fuel to the injectors their is 4 Injectors but i think that Dreamer and
Eric the Car guy might be on to sumthing about a leaking injector because when i took out the injectors to check them individually i might have misdiagnosed the
problem i watching for the spray and did not know much about them anyways that they might be leaking so im going to have to do this again any easys of
checking my tool are prehistoric cuz i dont have tools……………………………………… thanks guys and love the website its cool out. Forgot to mention that car was
laid up a while too because i could see signs that the car was not used for a long time and the throtle bodys are fine because i cleaned them out……………………………
I Just tested the injectors and they seem fine no leaks i dont think unless i have to leave them sit for a while but i do know i could nearly put a bet down that when
i put the injectors back and all the parts and dont start the car till the morning, it will start perfect and i have no idea what is wrong. Is their such a thing as too much
preasure in the fuel line cause i find the car runs ok if i release the fuel pump relay or is it a wiring problem??????????????????????????????
Well i took each injector out and had a 12 volt battery with two leads one to the positive and the other to the negative connected to the injector only stricking the
negative every two seconds. Had small amount of petrol in a hand pump connected to the injector holding the preasure with my hand for the spray. Only done
each injector for about 20 seconds test each… Or maybe i should Have sumone else have a look at them with the proper equipment.
A fuel pressure gauge is a good place to start as far as ‘proper equipment’ is concerned. To check for a leaking injector all you need do for starters is to run the engine with the pressure gauge connected and then shut the engine off, if the pressure drops significantly after shut off there is a leak somewhere in the system, it may not be the injector but to help narrow that down you can crip off the fuel return line while doing the test to help eliminate that. Also it’s a good idea to check the fuel pressure regulator as well as the fuel ‘pulser’ if you have one, it’s normally a round plastic part that’s located on the fuel rail that is NOT the fuel pressure regulator, both of those parts can leak causing fuel delievery issues.
Ok lads their is another issue that may not be quiet clear to me i have replaced the coolant temp switch with a second hand one and has’nt improved things but
if i plug in the spare one and heat it up with a lighter and start the car it will rev up fine are these two coolant sensors faulty????????????? Also i have a fuel
preasure gauge and do not have the proper fittings yet to connect it to the direct inlet to the injectors but connected it to the fuel return line and checked the
preasure i griped the return line and the preasure held in the injectors but as for not gripping it the preasure droped straight away after shutdown.
As the ECT sensor indicates to the ECM that the coolant’s temperature has risen, it will also change the fuel ratio’s and will adjust the fuel trims by take away fuel.
Did you ever ohm out the injectors or use some Noid lights to check the integrity of the injector circuit?
It will be interesting to see the results of an injector leak down test.
- You must be logged in to reply to this topic.