Jump to content
SAU Community

Recommended Posts

One of the things that I hate most about my car is that sometimes it wont rev above 5,200 rpm. It starts of with hesitating a little above 5,200, but within a week it becomes much harsher - it just wont rev past that point and the car starts to splutter and jerk about. Oddly the car runs really sweetly at anything under 5,000rpm. You don't know the problem is there until you hit that spot. Sometimes the problem goes away, after tinkering with carbs, adjusting the timing, a change in the weather etc... but it always comes back.

When I tried swapping the engine and related parts from the rally car to my car I made a mistake. I shook up the carbies (twin 2 inch SU's) and fouled them, so I couldn't get the car to go. I pushed it to the nearest mechanic who rebuilt the carbies but wired up the distributor incorrectly, frying my Petronix electronic ignition module. So I forked out for a new one of those too, along with a new coil, just in case.

The car has never run right since then for more than a week or two. Z-spares had it going well for a fortnight after a carby balance and air-fuel adjustment, but the problem crept back again.

I decided to take the car to a carby specialist to be tuned but he convinced me that the previous reco of the carbs was a botch-up, and would need to be completely redone with all genuine SU parts by a dedicated carby professional, like himself.

After two weeks he calls me to let me know that he is finishing off the carbs and they are in immaculate shape. Unfortunately the car STILL doesn't rev above 5,200 rpm. He thinks its the ignition system. Ha. Ha. Ha.

Before I re-rebuild the ignition system to match my re-rebuilt carbies, can anyone think of something else that might cause this problem?

Thanks.

Edited by coupe72001
Link to comment
https://www.sau.com.au/forums/topic/187154-another-grand-12-down-the-tube/
Share on other sites

  • Replies 63
  • Created
  • Last Reply

Top Posters In This Topic

maybe try to supply fuel externally via seperate fuel hose from a fuel tin into the carbies feed line just in case it is a blockage from the tank or something silly like that.

just to eliminate that as a possibilty.

russ

like does it just stop all together. or does it just loose heaps of power?

what coil you using? your electronic igntion, are you sing the "electronic" type coil or the origonal one?

It doesn't cut out altogether - it just spasms violently between 5,200 and 5,300 rather than soaring all the way up to the red-line. You can keep your foot to the floor all day, but it wont go past that point.

I am running the original points distributor - but the points are long gone and an after-market electronic ignition module is tucked in their in place. I have borrowed a standard and working electronic distributor (from an R30) from a mate and Ill see if that makes a difference tomorrow. Maybe there is a nasty hidden in my distributor somewhere as J mentioned above.

I have tried a few different coils. At the moment it a fairly standard but new Bosch item - I got it when I changed from points to electronic.

Fingers crossed anyway - we'll see what happens tomorrow.

The distributor is officially off the hook.

The next suspect is fuel pump/fuel pump mounting arrangement; maybe its just not sucking hard enough.

Unlike this experience in general.

Have you checked the float levels in the carbs? (who was the "expert" carbie builder?)

I'm guessing you are still using the mechanical fuel pump. Try adding an electric fuel pump as a "helper" (should be mounted near the tank so it pushes fuel).

Ok- B+M Fuel Systems in Richmond Vic have provided me with;

Carby rebuilds including jets, needles, seats, gaskets, floats, shafts... the whole box and dice.

Went to the 280zx distributor and it works way better than my Petronix system... do'h!

Fitted a piersburg(?) a very German and very expensive electric fuel pump below the level of the fuel tank to help out the neikkei(?) Japanese fuel pump in the boot.

27 - no joke - 27 attempts on the dyno to get it all going.

Final result... she goes - all the way to 7,000rpm with 88 screaming horses at the rear wheels. The question is for how long?

Cost - $1,500. Bummer about that part.

Anyway, hopefully nothing to nasty will break for a while now.

Wow - What a shock! The car got halfway home - maybe 5 kms, before the nasty came back. Today's new rev limit is 4,000rpm. The problem seems to emerge when the car is forced to sit in traffic for a while, so maybe there is some relationship to temperature.

Then I got a flat.

And the rear brakes are still grinding away for no apparent reason - having replaced the pads, machined the disks etc etc...

Honestly I am sick of the car and out of money. The project has cost easily 10 grand so far for it to look and run like an absolute piece of shit. I hate the thing.

Drew

I just got thinking about a previous post. Just because my coil is new doesn't mean its right. Should I be running a resistor type coil with a ballast resistor with the electronic distributor, or should I go for the non-resistor type (anyone got an R30 they can check?). Will a standard coil do, a GT-40, or will I need a "performance" coil of some sort? Could a faulty ancillary (eg taco) to the coil be causing me this bastard of a problem? (Not that the taco or anything else is obviously malfunctioning, for the record.)

To be honest, I think the fuel system has been pretty well sorted. Maybe I need a pro to look at the electrical side. What else can it be short of kids having stuck a banana up the exhaust?

D

SHIT!

for the price of all that you could of got a L24 EFI with a turbo setup.....

sometimes you gotta cut you losses and just drop the lot, but if it means this much to you just take it to a dat rally shop of somesort and give them a few weeks with it... let them know you'll pay by credit card adn just pay off the debt...

id fkn burn the shitter if it was mine.

SHIT!

for the price of all that you could of got a L24 EFI with a turbo setup.....

sometimes you gotta cut you losses and just drop the lot, but if it means this much to you just take it to a dat rally shop of somesort and give them a few weeks with it... let them know you'll pay by credit card adn just pay off the debt...

id fkn burn the shitter if it was mine.

I hear you... it's really starting to hurt now. I squirm to think of what I could have if I had dropped the 10G in one hit off the bat... an L28 tripple-webbered screamer, something nice through J-spec, 3,800 Big Macs...

If the coil experiment doesn't work out the car IS going of to Dat Rally Moorabbin and its staying there till its sorted. Ill never get back all the cash I've blown, so Im basically stuck with the the old girl till Im rich enough to consider another never-ending project (read basically never). You never know, maybe she's only another 2-3 years away from being all sorted.

Also I am going to replace all the rubber sections of fuel line in case there is a hidden flappy bit on the inside that is opening up and restricting the flow of fuel sometimes. Maybe $10 worth of hose could solve all my problems!

Also I am going to replace all the rubber sections of fuel line in case there is a hidden flappy bit on the inside that is opening up and restricting the flow of fuel sometimes. Maybe $10 worth of hose could solve all my problems!
Clean the fuel tank. There might be something in there that's blocking the pickup.

My R30 is just running a stock (black) Bosch ignition coil (no ballast resistor) - runs fine.

(If you want a going L24E engine, call round and take it away.)

Clean the fuel tank. There might be something in there that's blocking the pickup.

My R30 is just running a stock (black) Bosch ignition coil (no ballast resistor) - runs fine.

(If you want a going L24E engine, call round and take it away.)

hey i still got a few window motors here for ya!

what head do you have on the L24e????

and km??

hey i still got a few window motors here for ya!

what head do you have on the L24e????

and km??

Had given up on those, thought you'd forgotten :rolleyes:

Stock as, had about 285k on it. Still started first time, every time (unlike the prissy R32)

Ok thanks - that's great news that the ballast resistor is wrong as its an easy fix. That's also a really generous offer in relation to the L24E, but hopefully I won't need to consider it if I can finally get mine up and running right.

There has been a delay in operations though... I've lost my damn car keys! Arrrrgh!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • So, I started this repair and got as far as "fixing" the holes with some fibreglass. God all those years working on boats came back quickly. I decided I'd reach out to some rust guys just to see what they would say about it. I came across a guy about 40 mins away and went to see him. He said the windscreen needs to come out, that there might be some more bits around the windscreen and he'd quote them at the time. But his quote was $300 to remove and replace windscreen and $3k for the damage he can see. He said he could respray the roof for $1200 and the bonnet for another $800 (somebody has previously rattle canned it, its horrendous). This is $5300 + any small additional bits. It's a lot, I get that and the name of one of my fave youtube channels 'Not Economically Viable' comes to mind.  I'm not being financially rational, but I've taken him up on the quote. He's opening a new shop in November with more room, so we're waiting for that. I'll leave the currently missing headliner out until then. I'm looking forward to it being fixed and having the paint looking nice again (lots of clear coat issues on the roof too). / flame suit on.
    • Oh and some up-and-comings; New rear drivers wheel bearing. I'll do that this weekend while the diff is out. The car is already up and the d/c axles and missing exhaust will help with space. This is the last bearing for me to do and I've been dragging my feet on it. I also have some new EBC blue stuff pads for the car and some new brake fluid. I haven't ever flushed the fluid in this car and looking forward to it. I have 600 degree fluid to put in. Not exactly "race fluid" but better than the typical stuff I have been using.
    • A proper clutch/plate type mechanical diff with quite a lot of pre-load and high locking % is better for drifting. Much more consistent in its behaviour. A helical can be annoyingly vague and inconsistent in how it responds under the sorts of abuse found in drifting.
    • Some updates here. I pulled the entire interior out, minus some trim to respray the seats with Colourlock dye. It turned out really nice though I accidentally let the dog in the car after and she scratched up the front seat.  This is what it looked like before, the colour was just washing out everywhere but thankfully the leather was in good nic. Then after the respray   And after the bloody dog jumped in The headliner is out waiting to be retrimmed, but it will stay out now until Nov - see why below. I replaced the stereo/headunit with a period-styled Android headunit. I have no after pics, but I'll get some. This is because of the missing pixels. I tried to fix this twice with replacement ribbon cables but couldn't. Also the bluetooth interface I'd bought for this was crap. Then there's the rusty roof. Pics and info in this other thread. I have decided to get this repaired professionally, but I'll update that thread. This is why the headliner will stay out for now. I'll be getting the roof and bonnet resprayed at the same time the rust is fixed. I also had an interesting issue with my drivers door lock.  For a small period I was having issues getting any 12v power to the car - I mean *any*. It would have no dash lights, nothing. It happened while I was at the shops and I couldn't get in the car. So, we had 2 problems. The most pressing here is that I was locked out. I have only a single physical key hole on the car, the drivers door and no amount of turning would unlock the car. Surely it doesn't need power for this? The second issue is why am I losing all power periodically, The battery isn't dead, its almost like the battery isn't even there. Two issues that were surprisingly easy to fix. You fellow BMW over-engineering lovers will appreciate this. The lock in the door has 5 states; mechanical lock, electric lock, neutral, electric unlock, mechanical unlock achieved at -90 degrees, -45 degrees, 0 degrees, 45 degrees and 90 degrees. Although, the unlock is towards the front of the car, so opposite for LHD countries. Sticking the key in and turning 45 left or right is what is used 99% of the time. It activates the central locking etc. 90 degrees is for dead battery access and, obvs, only un/locks the one door. But because the mechanical lock is never used and is 27 years old, it seizes up. I was totally unable to turn the key far enough to get to the mechanical unlock (At the time of locking myself out, I didn't even know this was a thing). I eventually did it with some vicegrips and teflon spray.  I made a quick vid for other E39 peeps.   The battery issue is totally new to me also - It wasn't making sufficient contact between the post and the terminal. The terminal was bolted on tight, but the car wouldn't have power. After checking the battery with my multimeter I accidentally contacted the terminal and the battery post and the car got power. The battery was only a few years old and in good condition. I cleaned the post and the terminal with a wire brush, bolted it back on tight and never had the issue again. I'm still surprised that despite having solid contact it didn't work. Also, the car was getting Warragamba sized pools of water in the back when it rained. My initial concern was another rust problem. But when I went out on Weds while it was raining and while I had no headliner in I could see a steady stream of water coming through the roof mounted aerial. As this aerial is for the (now removed) car phone I pulled it out and whacked a blanking grommet in the hole. It seems fine now. I'm thinking I might get the hole permanently filled when the rust is fixed. Moving forward and things in progress; The tailgate needs some attention. I have taken all the trim off to clean it all and address some small rust spots. I have partially done all of this but I'll finish it up hopefully this weekend. As all the trim are now entirely devoid of trim clips I have bought a heap of strong velcro and I'm hoping it does a good enough job as any of this trim in good condition is super expensive and usually in Europe as we dont have many of the wagons here. Suspension and brakes!!! This is exciting. In the front; New control arms New sway bar links New lower Eibach springs (the only modification I'm planning on this car) M Sport shocks (these came with the car and will replace the longer shocks in the car) New top mounts Used 540i calipers (stock brakes suck!) New 540i disks and pads (22x296 mm for 528 and 30x334 mm for 540i) New front wheel bearings (thank all that is holy for bolt on bearings!) Annnnd in the back; New control arms New sway bar links Adjustable air suspension arms (fool the car into what the current height is so the self levelling suspension can match the new front ride height) New ball joints I'll also be doing a brake fluid flush while I'm in there. I'm planning on switching the car over to the 16's that came with it so I can clean up and respray the M Sport 17's. They've lost a lot of colour over the years and have some gutter rash. None of this will start until the E90 is back.
    • You mean you will regret it for drifting duties? I don't quite follow.
×
×
  • Create New...