3.5 efi wont start after running rough

Hi I have a 3.5 efi flapper from a range rover now in my 90. It was running great went a run in it for about 30 miles (had already been using it for a week or so 20 miles a day) then it started missing and cutting out. I cleaned all plugs and checked for spark (good spark). Plugs get soaked after cranking (so getting fuel) Took AFM off it was jammed open (Fixed and put it back in - No change). I checked all wiring and that is fine also - all solenoids are clicking. It is now cranking but not even trying to start all vacums are good.
Dizzy cap and rotar good.

What can i check next?

Cheers

i'll bet its flooded to ****.

i have had this quite a few times before i knew what the problem was. i was cranking the engine over one day to check the spark on all plugs, flooded it.

i was cranking the engine over one day to help me get a new set of fan belts on, flooded it.

the ony way i got it going was with a tow.

however i have had another very odd situation where i drove it to an off road day, hours drive, no probs. parked up for a butty, then set about into the site, within a few minutes it started spluttering, then began to cut out, then would not restart.

spent about 4 hours trying different things, towed it round and round like i did previosuly to get it running, nothing.

ended up giving up, caled rac. they couldnt figure it so got me a lift home.

got home, checked igntiuon timing, had gone WAY out. had only just checked it a few days before driving all that way to the off road site.

explain that one! (and then check your igntion timing!)

Thanks Mr Noisy will get myself out after work reset ignition timing and take spark plugs out and let it dry itself out then re try tomorrow night. Dizzy does not seem to have moved though? But will give it a go as how you describe is exact same as my situation!

i was under the impression that somewthing must have moved internally in the dizzy which had knocked the timing out a fair bit.

check it out anyway!

Will do thanks again will let you know how i get on

bryhp said:

Hi I have a 3.5 efi flapper from a range rover now in my 90. It was running great went a run in it for about 30 miles (had already been using it for a week or so 20 miles a day) then it started missing and cutting out. I cleaned all plugs and checked for spark (good spark). Plugs get soaked after cranking (so getting fuel) Took AFM off it was jammed open (Fixed and put it back in - No change). I checked all wiring and that is fine also - all solenoids are clicking. It is now cranking but not even trying to start all vacums are good.
Dizzy cap and rotar good.

What can i check next?

Cheers

Click to expand...

mines just done this, been a daily driver since fitted over a year ago, few issues but nothing major. drove to work friday morning sweet as a nut. start it to come home and it's spluttering and coughing, wont idle but runs with throttle so drive home. have a quick look under the bonnet, wiggle a few leads and stuff as you do, make sure everythings more or less where it should be and re-start it and it's sweet as a nut. used it saturday, no issues. monday morning, starts but maybe running on three at best. not good. changed cap and rotor, same. substite ecu, same. cleaned plugs, same, checked most electrical connections but not had time to do any continuity tests yet. will be weekend before i get chance to have a proper look now. :doh:

As i say will check ignition timming tomorrow let any fuel evaporate and will let you know my findings. 3.5 efi mine did same drove ok on throttle but felt way down on power was after a few steep hill climbs and through a few fields. I changed from carbs to efi for reliability its fustrating. Will post tomorrow

tbh i find the efi reliable, its the igntion that has always been trouble for me.

checked timing so thats bang on. Any other suggestions? Coughs after turning over for ages but not even close to starting?????

mine was regualr coughcough cough but nowhere near to starting.

one time i managed to get it started by having a mate crank it over and i simply slowly rotaed the dizzy back and forth untiul i found the sweetest spot and i slowly came to life. set timing and then it was perfect.

i also had a simialr scenario where it would only run with the dizzy in one position but it ran like ****. one of the wires had snapped to the ignition amp and would contact in one position, but then of course the timing was out.

im sure yoiuve done this already, but check everything.

have you got a nice bright spark at every plug? does fuel spray out of the plug holes if you crank it over with the plugs out?

if you have got fuel, you have got spark and yopu have got compression, then it can only be a timing problem stopping it from running.

could it be blocked exhaust ??? Put a bag over it and it only slightly inflated during cranking as i am on my own working on this tonight i have no one to crank while i put my hand over. My other car blows bag off and away!!!!

you would hear air bursting out of every crack and cranny in the exhaust system if it was blacked. only the cats could block up, most unlikely you have them though.

Ye good point and i dont have any cats(tubular manifolds). There is a sensor behind the dizzy on the inlet looks like a wire may be broken or bad contact will replace today. Annoying everyone says it has to be something straight forward. Tried moving dizzy while someone cranked it last night no joy with that either.

could it be a faulty coolant tempreture sensor???

Go back to basics.

If I understand correctly you have fuel and you have sparks. The ignition timing is correct.

You say you have a good strong spark - A nice fat blue one I hope. Have you checked the inside of the dizzy cap for evidence of any track marks? Check the rotor arm as well.

Check your battery is in good order.

Next I would suggest checking the ignition system, have a careful look at all the connections, corroded and frayed wires can cause certain maladies.

If all that checks out then I guess you're in to checking sensors. You say the flap on the AFM was stuck? is it now moving freely? Is you air filter blocked? Are your engine breathers clear?

If the cooolant thermistor is suspect you could try bridging across the connector with a paper clip to trick the ecu in to thinking the engine is hot. If you think it is flooded and it could well be, (as Noisey said) I have also had flooding issues in the past then you need to try advancing your ignition timing slightly then foot flat to the floor and crank it over - it might catch it might not.

Have you checked the throttle potentiometer? Stick a meter on it and check base setting (voltage) then check for smooth scaling from closed to WOT. The movement of the throttle pot should also be smooth with no notchiness.

That's all I can think of at the minute. Hope that helps.

found vacum hose to dizzy was split - it is now trying to start but back fires through inlet will need to re set ignition timing?

Cheers for the help so far!!!!!!!!!!!!!!!

bryhp said:

found vacum hose to dizzy was split

Click to expand...

I thought you said all vacumms were good:doh:

Hopefully that should mean it will fire up now. Good luck.

still not firing up!!!! trying but still just coughing aaaaaarrrrrrrrrggggggggghhhhhhh

If it back fires through inlet it seems that there is a spark when the inlet valve is open perhaps?

Does this point to the cam timing being out?

Guess you need to take the rockers off and check that tdc compression for each cylinder also has both valves closed.

If you have fuel, you have correct ignition timing then the only thing you are missing is compression/air.

Best check that maybe?

As been said before. These engines are VERY easy to flood.

Take all the plugs out and check their condition, dry off, and ideally replace.