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Forum friends; I am in Desperate need of HELP/ Suggestions. After having replaced head gasket, intake manifold gasket, power steering reservior AND hoses, new KYB shocks All around, Fuel Filter, New Genuine Radiator and Thermostat and going to Mobil 1 syn. Oil...... I am getting "check engine " light and with terrible running (idle) and No power/accelleration (barely reaching 40-45 mph). After reading codes P0301, P0303, P1313, P1316; the first 2 codes being "misfire" on cyl 1 and 3 - I replaced the spark plugs (OE champion) and the ignition wires on these 2 cylinders Only. The truck idles VERY rough and has very little power and is way louder than normal. Upon checking spark- i am getting a strong blue spark on cyl 1 and 2 and a 'not as bright-purple' spark on cyl 3. Any ideas/suggestions are appreciated as my Land Rover certified mechanic has recently moved out of town and i Can NOT afford the dealer at this time(I'm unemployed)
Truck has 160,00 miles and i have pampered her since i have had her. Also has been converted to coil springs.
I would Appreciate ALL Help and Input from the forum family ....THANKS
 

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As misfire is on 2 adjacent cylinders have you done a compression check to make sure no problems there?
Also have you checked for vacuum leaks?
The coils are separate on the GEMS so you could swap them around to rule coils out.
The extra noise could be the head gasket or exhaust manifold gasket - both will affect running.

Finally it is a good idea to fill in profile with your location.
 

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THANKS AMcK...............For your reply !!! Is the compression test and vacuum leak test something i can do myself OR must it be done at pro shop. And YES i do have the GEMS engine; So am i able to remove coil pack WITHOUT taking off air intake housing/plenum??? Can You recommend any where that will give me DIY instructions for comp. test and / or vacuum leak test ?? Thanks Again
 

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compression test is a diy job.

Remove plugs or ht leads. Connect a compression gauge in the spark plug hole and turn over the engine using starter, the gauge reads the compression.

Vacuum leak test can be done with either a gauge or some have detailed on this site the use of a flamable spray on the engine inlets components while the engine is running (To see if the engine revs change with the addition of more fuel being sucked in)
 

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I find that most often times people forget about the injectors. If the compression checks "OK" I would look into the injectors. Dirt small cracks or a bad o ring can cause an engine to missfire
 

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Discussion Starter #8
2 Quick Questions.....????? !!!!!

2 'quick' questions RE: Misfire
Guys......THANKS for All the input and suggestions; It has really been useful in my diagnosis of my misfire on cyl 1 and cyl 3. I am currently awaiting arrival of the Magnecor 8mm Electrosport ignition wire/lead. Also have 8 new OE Champion spark plugs from dealer. Two quick questions;...........1) does anyone have suggestions for 'spark plugs' that perform "BETTER" than the OE Champion plug?? Please be specific of plug type (brand, model, and "gap" )..............and

2) On my 1997 RR 4.6 HSE; is it necessary to remove the intake plenum to change the Ignition Coil Pack on this model ???? While replacing wires/leads And spark plugs; I am tempted to Also replace Coil Pack "IF" it doesn't require removal of intake plenum(then i can DIY).........THANKS All
6RedRover9 is online now Report Post Edit/Delete Message
 

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The OE plugs are the ones to go for.
Def. a DIY job. The procedure within RAVE shows the coil pack being removed without removing the inlet manifold.
(enjoy sore knees while you peer over the inlet with your arse in the air)
If you haven't got it yet get a copy of Rave.
 

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10 mins to remove coil pack, no need to strip out top cover but it does help if you've never done it before.

Go genuine Champion spark plugs and leads, I replace these two items alone on many, many rangies and the difference is night and day.

Any new HT lead when new will work but its the time difference vs the the genuine ones that make the difference, 80 000km max and leads should be replaced regardless

You can use Champion EON series of plugs but they cost more but there's no benefit
 

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Discussion Starter #12
STILL Misfiring.....!!!! Whats Really Going ON???
First off; THANKS for All the Help, Advise and Suggestions from this forums Rover drivers....But i still have NOT got this 'Misfire' Solved.
So just yesterday i replaced ALL ignition wires and spark plugs using genuine plug wires(which actually DONT have a manufactures 'name' on them; used to be Lucas)and the OE champion spark plug. I also replaced the fuel pump "relay" under hood because it had the brown 'burn mark on it. The plugs came 'pre gapped and i verified ALL plugs to be .035 or so ;as per owners manual.
......Upon starting truck it idled a little better but still rough and check engine light still ON. I let it idle for 15-20 min. but No change in running or light.
So this morning i took truck to auto parts store to use their OBD II scanner. I got the following codes; P0301 P0303 P1313 P1316 ...All codes which i had Before BUT this time I also got code P0300 . I used the scanner to Clear the codes and the "check engine" light on the dash went OFF.
So on about the second mile of my 3 mile drive home; the "check engine" light comes Back ON !! I am truly at wits end!! I am pulling my hair out over this issue ...... new plugs , new wires( made sure i routed them properly) new fuel pump relay ... **** !!! Now what ?? Please HELP guys; I CANNOT Afford the dealer's labor rate. There is Only 1 Land Rover dealer in this town and they have 'raped' Me before so that is NOT an Option. THANKS; in advance for all Help from those who 'feel my pain'.......... :crybaby2: :?: /:(
 

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What where your results from the compression test - if cyl 1 and 3 are the same as all the others that will at least rule out the engine itself and you can concentrate on the fuelling and ignition.

Have you tried swapping the coil sections around to see if misfire code follows?

Does disconnecting the MAF make any difference to the running?

Have you checked for any vacuum leaks?

Are you able to read values for O2 and MAF sensors

Could be injectors as previously said - have you checked O rings? You could try swapping injectors to different cylinders and see if misfire codes follow.
 

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Discussion Starter #14
AMcK said:
What where your results from the compression test - if cyl 1 and 3 are the same as all the others that will at least rule out the engine itself and you can concentrate on the fuelling and ignition.

Have you tried swapping the coil sections around to see if misfire code follows?

Does disconnecting the MAF make any difference to the running?

Have you checked for any vacuum leaks?

Are you able to read values for O2 and MAF sensors

Could be injectors as previously said - have you checked O rings? You could try swapping injectors to different cylinders and see if misfire codes follow.


THANKS AMcK....................I am Not able to do my own compression test. Can you briefly explain how to swap coils sections; I was able to get close up enough in engine well to be comfortable removing coil pack. I have Not tried disconnecting MAF. What would i be looking for by disconnecting MAF.(It was replaced about 20k miles ago with a Sagem unit). I do not know how to check for vacuum leaks. Please advice.... I dont know how to read values for 02 and MAF sensors. Rover tech who did my head gasket replacement and and replaced broken rod on cyl 8 had confirmed that O rings were OK. He has since moved 'out of state' ; Too bad for Me , huh??? So how difficult is it to remove fuel injectors?? THANKS again AMcK
 

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the coil pack comes in 4 sections each one is interchangable with each other you can just swap them around. You will see when you get the coil pack out.

The engine should run ok without the MAF connected (even though some including me find the car won't run at all with it disconnected) the car will go into basic settings setup and would show the running problem is not maf related. As said this test did nothing for me as my car seems to like the maf.
If yours runs better without the maf then your maf is the problem. clean and recheck or replace.

Vacuum leaks need a Vacuum gauge to check correctly. (Plug in the gauge and read the results)

O2 readings are read by diagnostic reader (such as mid ranged odb2 readers) (again plug into diagnostic port and read values)

hope this helps
 

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6RedRover9 said:
THANKS AMcK....................I am Not able to do my own compression test. Can you briefly explain how to swap coils sections; I was able to get close up enough in engine well to be comfortable removing coil pack. I have Not tried disconnecting MAF. What would i be looking for by disconnecting MAF.(It was replaced about 20k miles ago with a Sagem unit). I do not know how to check for vacuum leaks. Please advice.... I dont know how to read values for 02 and MAF sensors. Rover tech who did my head gasket replacement and and replaced broken rod on cyl 8 had confirmed that O rings were OK. He has since moved 'out of state' ; Too bad for Me , huh??? So how difficult is it to remove fuel injectors?? THANKS again AMcK
If you can change a spark plug you can do a compression test - the test gauges are less than $15 - have a look here - http://cgi.ebay.com/ebaymotors/CYLINDER ... 3550wt_924

Was the MAF definitely a genuine, new Sagem unit - if so should be OK.

Vacuum leaks, as already said earlier in the post, can be done by spraying a flammable liquid around any joins in the inlet, betwwen the MAF and the cylinder heads. Something like the spays that are designed to help start an engine - http://www.youtube.com/watch?v=Sc89tBlX ... re=related

Or the way I do it is to use propane from a cylinder via a regulator and hose or you could use a blow torch. After about 30 seconds of searching I found the following video that may help you - http://www.youtube.com/watch?v=YH6306zM ... re=related

The video shows carbs, but will work with any engine.
 

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Discussion Starter #17
UPDATE:Re: 1997 RR 4.6 HSE CONSTANT Misfire on Cyl. 1 and 3

..........UPDATE !!!!!!!!!!!!!!!!!!!!!

Still trying to correct my misfire issue; So today i completely removed entire Ignition Coil assembly. I tested each coil and each coil showed 'resistance' of 1.5 ohms. I cleaned body of assembly while looking for physical defects or ruptures; but found NONE. I also applied "electrical connection cleaner' to wiring connector and ignition leads slots. Reconnected coil assembly, made sure each wire lead properly positioned. Still Misfiring AND check engine light.
So Ignition Coil "appears" to be OK. ....Installed new genuine ignition wires And new Champion spark plugs (OE model)
......Well what should i test or look into Next ??? I desperately need to get this truck on the road as my "Daily Driver". Please HELP !!!
................................T H A N K S ! ! ! ...........................
 

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check the connections to the injectors, i had a missfire on one cyl and it was a loose connection to the injector.
Remove each one on cyl 1 and 3, clean replace and test.

If no,
The injectors have 2 poles which come from the ecu (box behind the battery). You could test continuity between the injector and the pin of the connector in that box.
I think one pole is common to all injectors.
Pin connections are within rave
 

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Just fixed a chronic misfire on #7

first step was swap plug and wire from #8, no improvement

second step, swap out with a known work MAF and reset values, no improvement

thrid step, replace injector and coil, since both require the upper intake to be removed I did them together, this fixed my misfire but I cant tell you which was problem

I rover specialist told me when the coils go bad you usually a pair of misfires, I have a bosch engine so I dont know if #1 & #3 share the same coil on a 97
 
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