Mi 16 Wont Rev Past 5k

[Guest rich1977]

right took the Mi 16 out yesterday foor a good run as I have finnaly taxed her after tidying the interior up since buying her, problem ive got is she wont rev past 5k at full throttle I can get her up to 6k on half throttle but she is hesitant with it, Ive changed the plugs recently and double checked the firing order I have even swapped the rev counter as I thought that might be playing up, when it does it its like it looses spark (like when you turn the car off while still running) on one occasion she chucked a massive flame out the zorst due to the unburnt fuel lol, I dont think its rev limiter as she is on carbs and used to rev to 8k (bottom end is ballanced)

 

now engine is 9k old after full rebuild is running Webber 45's but she has been off the road for nearly a year but was started daily by previous owner due to moving it in and out of his garage, is this likely to be ignition amp or should I change the leads which is the only thing I havent done as I think i might be getting one sparking out onto the cylinder head. if I do change the leads do I get 1.9 gti 8v ones or 16v ones bearing in mind it has the 205 dissy.

 

thanks for any help.

 

rich

[Anthony 1,003]

Try a different ignition amp first, as these can give a rev limiter like misfire at high revs when they fail (or overheat due to poor contact with the heatsink)

[Guest rich1977]

right then ive took leads out yesterday to check them to find the insulation that sits around the plug had all cracked due to the plugs sitting in water, so i have dropped plugs out and turned engine over to get rid of the water, ive now cleaned the plugs and swapped the leads. this made it alot better and she was pulling alot better although still seemed a bit rough but seemed more like a fuel problem so I adjusted the fuel pressure reg by a 1/4 turn and that has made it alot better.

 

still a little hesitant but not like hitting a brick wall, the ignition amp is 6 months old but I have found this morning that the plug from the dissy to the amp has started to fall apart so I will re-wire this today. I have noticed that when I aint accelerating the rev counter is bouncing slightly is this a bad earth or becuase the insulation around the ignition amp plug has started to come away leaving bare wires exposed?

[Miles 331 1 Cars]

Is the amp a OE Bosch one or a crappy Intermotor etc, I've had loads of problems with the pattern one, Best getting a S/H Bosch one at any cost

[Guest rich1977]

will have a look 2morro

[Guest rich1977]

right then this car is really beginning to test my sanity.

 

I bought a known good ignition amp and coil from a forum member this week and fitted it took her for a drive and all seemed fine.

 

I took her for a longer drive today and all was fine for first 10 mins on half throttle and would go over 5k I came off a island and decided to give it some beans when a chav in a corsa was trying to take my rear end off while overtaking car behind me all was fine untill i let off the car then just cut out and wouldn't re-start unless i clutched it (similar to running out of fuel) i parked up and she would start but not pull away under load.

 

so far ive replaced plugs,leads,dizzy cap,rotor arm, gearbox and coil earth, ignition amp and coil so almost all the ignition system bar the actual dizzy have been replaced and i cant see it being that tbh as theres no movement in it at all, whcih brings me to the carbs and fuel regs she is running injection pump with the 2 regs now up until last week the first reg would whistle when pump was on although recently it has stopped whistling so fuel pressure could of got screwed up somehow. is it possible that the above symptons are fuel pressure orientated and shes being starved of fuel at full throttle or even possibly getting to much fuel and choking itself up?

 

any opinion welcome before I crack ebay the car and go and build another rover turbo

[welshpug 1,657]

check the ecu temp sender

[Guest rich1977]

wheres that and will it have one seeing as its on carbs

[davev 1]

it will still have a temp sensor but i would have thought it would be redundant because of the carbs.

 

im watching the post with interest as althought i dont have exactly the same problem im sure i have similar issues.

 

dave.

[taylorspug 7]

You wont be running an ECU temp sender if you are on carbs. But just so you know its in the side of the head, under the dizzy!

[Jonmurgie 2]

It will be the crank position sensor or related wiring breaking down... the EXACT same thing happened with my Mi on the dyno and we traced it to the CPS so I'd look there

 

Here's a link to a vid of the problem we encountered on the dyno:

[jonnie205 1]

No CPS he's on carbs.

 

i would try the dizzy next, maybe it has broken down inside and is giving a vary bad timing after 5k

Edited February 19, 2007 by jonnie205

[Guest rich1977]

right then just had a look at car again today as i had 5 mins and decided to check the dizzy which is fine, but i have found that she wont fire when leads are set up via this config.

 

 

basically it will turn over then spit a massive flame out the back

 

she will only fire and run right with leads keeping the corect fireing order but number one being where number 3 is on above pic

 

shes booked in to get carbs checked 2morro but guy said he doubts its the carbs as its sounds like ignition side and for what its worth my car does exactly the same as in the dyno vid above only worse

[Guest rich1977]

right then took it to be set up today but guy couldnt get it done due to the petrol crissis atm and hes snowed under with cars that have ecu faults ect. he had a quick look though and took it for a spin and said carbs are slightly out of balance but its not a carbs problem its def ignition (guys been tradeing for 45 years so knows his stuff).

 

now hes suggested i try and find problem as he will charge 40 quid a hour to fault find on the dyno so to re-cap I have checked and cleaned the dizzy cap, rotor arm, and distributor, all new leads and plugs ignition amp swapped for a known good one aswell as the coil.

 

The problem occurs at around 5-6k and she will now get past that but it will kangaroo and hold back (kind of misfire but rev counter stays as it is) then clear around 6k and shoot off.

 

now hes told me to check the fuel pressure is around 3.5 psi, How do i do this i tried to check last weekend with a gauge i bought off ebay but it wasn't reading anything full stop i put it between the first carb and the 2nd fuel reg.

 

I noticed the other day that the lead that goes between the ignition amp and ecu has some damage to the screen could this be the cause?

 

he also said that a dodgy alternator could cuase the problem aswell at high rpm as i might be getting weak spark now while driving normally guage says 13-14v if i boot it it drops to around 11.5v

 

any other suggestions greatly accepted Ive had the car now for 8 weeks and havent been able to drive it in anger once which after selling a 240bhp turbo to obtian the pug its getting me down and considering selling up and going back to turbos

[jackherer 543]

11.5v definitely sounds like a dodgy alternator.

[welshpug 1,657]

now you've mentioned the low voltage reading it definitely sounds like a dying alternator.

 

I had a few flat spots and the odd occasion of unwillingness to rev before i replaced mine, now it pulls the redline sweetly.

[Guest rich1977]

so if i disconnect the alternator will this be a suitable way of testing if its the alternator causing the problem? bassicly run it off a fully charged battery as dont fancy buying yet more parts that might not solve the fualt

[taylorspug 7]

No you will need to get a good alternator on there, the lack of charge will be causing weak spark so no charge at all will only make the problem worse. If the voltage is 13-14 volts at idle and then dropping away to 11v, then its almost certainly an alternator issue, as its obviously all connected up properly to be charging in the first place.

[Guest rich1977]

wasnt the alternator in the end i checked it with my meter rather than relying on the amp guage on head unit and im getting 13v-14v and iddle traced it to running on 3 cylinders but cant find out why all the leads seem fine and all the plugs spark and it isnt doing it on a specific cylinder either its jumps between although seem to isolated it down to 1-3, ive noticed king lead might be broke just now in the dark as if i disconnect a lead the king lead arcs to the coil reconnect the lead on either 1-3 and it no longer does it, going to get a new one 2morro and see what happens

[djinuk 2]

im having very similar issues with tu engine, but believe it or not it sorted itself out :S, which was strange.