I recently swapped the 44IDFs for 48IDAs on short manifolds. The car goes about the same but is way cooler now (I'm talking style not engine temp).

The trouble is it doesn't like to restart. It starts first go when cold. Easy. But when the car has been running for just a minute to a long drive it won't restart. It doesn't even half fire, pop or attempt to start. It's as if there's no spark or as if it's flooded. I have to let it sit for about 3 minutes and then it will start

It never did this with the IDFs.

The 44IDFs had 36 vents while the IDAs have 37 vents.
The 44IDFs required 135 mains the IDAs need 140s.
I had 55 idles in both. Maybe the IDAs need 60s?

Any thoughts?

Thanks in advance.

CT

thats bizarre.......i can understand when its hot, but not after only a minute !

Or possibly 50 idle's CT ???

Not even a pop makes me think rich rather than lean.

Especially since you say it starts easy when cold... my engines with Weber's have always been a pain to start cold, but restart just fine when hot.

I can't understand it either. After a long drive I put my hand on the carb and it was onlly warm. I touched the manifold and I could hold my hand on it. So the fuel isn't boiling or getting a vapour lock.

I'm interested in getting bigger idles on the principle that a hot engine needs more fuel. It was lean down low when I was running the 135 mains. The 140s solved that.

Hmmmmmmmmmm

Oh and hot engines normally need less fuel !!!

That's why you have choke's on carbs (that block off air, so hence give more fuel) and Temp Correction tables on EFI that add in fuel when cold.

It had a stumble taking off from the lights when I used 135 mains and the idle mixtures wound in a bit more. I fixed it with 140 mains (the plugs were a tad white) and half a turn out on the idle mixtures.

I might try some extreme mixture adjustments tomorrow.

I don't have any other IDA idle jets at the moment.

Cheers gents.

Set your idle mixture on the rich side of the sweet window and see how the 'stumble' reacts, also useable info is how far out on average are the mixture screws and performance best nearest starting or after good warmup.

Are the float levels correct? If too high, that can happen.

IDA's like low fuel pressure below 3psi.

You didn't say what size air correction jets you are using.
What does it idle like ? Does the engine stall after a while if you it leave idling ?
Also what size are the idle jet holders or idle air jets ?

I made up a bracket to position the needle and seat where it would be if the carb top was on. Then I filled the float bowl up with fuel to get the float to it's maximum height. Then I made up a little plastic measure for the float with 5.0mm and 3.5mm measures.







I think the floats were a bit high at about 6 mm and 6.5 mm when they should've been at 5.5. I've reset them to about 4mm. Unfortunately I couldn't test this out because the battery was flat. The car's idiot owner left the lights on.

I originally set up the malpassi fuel regulator at 2 psi. But that was years ago so it wouldn't hurt to recheck it.

Thanks for the suggestions gents.

Col, can you send me some 60 idles and 145 mains to try please?

Cheers CT

Hi CT

Are the accelerator pump nozzles spraying?

Steve

have you checked out the spark when it wont start?........you mentioned it, but you did do the check yeah?

i had the same symptoms with a die-ing coil

Hi

Good point Damo.

It could be number of things.

Your ignition switch could have high resistance when it gets hot, check to see if you have battery voltage at the coil at rest with the ignition and when cranking.

You could try fitting relay in the ignition circuit.

Steve

Well, CT........did you find the problem? If so, what was it?

Yeah, CT's been a bit quiet on the solution hey... maybe he's busy working on Jak's "just mid mount it" fix ???

Nah, he's a away, he thinks that because the IDA's came off a V8 that they are just carsick from travelling backwards & need a 3 minute breather every time it's turned off.

Jak

And the Oscar goes to.............................Daimo.

No spark is the correct answer.

The MSD is cactus, caput, buggered and on the fritz.

There was no spark so I cracked open the MSD manual and got to point number 7 in the diagnostics which basically says it's fecked.

I rewired it as standard and it starts in a split second. Problem solved.

Yay, I thought. After the broken oil cooler, buggered clutch bearing, oil line dramas, dead battery, broken battery charger, and now MSD I can finally make it to a track day on my third attempt.

The car drove faultlessly out of the garage at 10pm tonight. Then up the street on 2 cylinders.

I know when I'm beaten

Thanks everyone for you suggestions. What's a good ignition system. So far I've been through the Jaycar CDI kit (twice) and a MSD. Maybe it's the plate in my head which destroys electronics. My computer constantly plays up and I throw out a lot of electronic gadgets which don't seem to want to live anymore after I've owned them for a while.

I honestly feel like pushing my beetle into Pittwater to see if it floats.

Fed up dot com

i don't know shiz.......and don't ever forget that!

you nut bag.......there is a dam here i can throw it in for you.....hell i will even come and pic it up and push it in ...........drive it here and i could take that metal plate out of ya head???? no guarantees

so where you at now............you got it running fine but then fell back onto 2 up the street?

mid mount or rex conversion is the answer!

Well the bright side is, it's easy to start....

guess she's down on power on 2 cylinders though !!!!!

It's purring like rocks through a blender.

Tempting Daimo if you didn't live so far away.

BROKEN you think or back to chasing air, fuel, spark?

I think the plugs are sooty or the gap is too big for the std ign.

A new CDI is probably the best place to start.

I'm going to have to look at the floats again. They were stopping at the needle body not at the point at which they'd stop during normal operation. So they're set a bit too low.

I've received some valuable advice via PM.

More tinkering.

race cars hey...........poor neglected thing just wants some luvin

keep us informed....

I couldn't let it rest.

Running on 2 cylinders, it's more likely to be fuel related. I looked down the carbs and 1/2 side accelerator pumps weren't squirting. What now?

The float bowl was empty. Maybe the new needle and seat was stuck or maybe the float level was totally wrong.

I've now learned to fill the fuel bowls via the needle and seat to get the proper closed point in the needle and seat (thanks Henry) and the exat operating fuel level and float height above the carb body. Now I realise how much the needle moves making my previous measurements way out.

The good news is that it now starts easily and runs on 4 cylinders. It idles beautifully. I still have to do the 3/4 side float height again applying my new found wisdom.

I did miss another track day today. Gremlines 3, me 0.