1.4 only running on 3 cylinders

Post by **Jason B** » 18 Apr 2008 12:54 am

timing?

Post by **Pappa** » 18 Apr 2008 07:50 pm

Could be, but it seems very complicated to check, and i don't have a strobe lamp

But the timing is probably off, better fix it.

Anyway. Today i changed all the plugs once again, this time to NGK BPR6ES plugs, which are supposed to be good. The ones that were in there were cheap-o-rama's (Eyquem or something).

Also i replaced the ground wire on the renix since it measured 7 ohms or so. Now i have a 0 ohm ground connection as i should have. All the other tests in the green book seems to be okay except for the timing test (don't have the equipment).

It runs a little better and smoother now. Sometimes it actually runs really smooth for 2 seconds then back to shaking and "putt"-"putt"-ing.
If i apply throttle up to about 1500rpm and so and yank the plug that don't work at idle then it runs a lot worse, so it seems to ignite okay at speeds above 1500 or so.

I don't know if this might be due to some problem (dirt?) with the flywheel sensor (what does this actually do?) or the flywheel? Or maybe something with the vacuum to the renix?

Anyway I am replacing the clutch so I'll look at the flywheel and sensor really soon to see if there's something there that might need to be cleaned or whatever - does the renix get timing information from the flywheel?

Post by **jtbo** » 18 Apr 2008 09:49 pm

Yes, renix gets timing information from flywheel, there can be all sort of trouble if that information is not correct.

Post by **Pappa** » 18 Apr 2008 10:37 pm

Okay. Since my clutch is worn out i can only assume there is lots of clutch plate dust and whatnot in there. It'll be interesting to say the least

Post by **Jason B** » 19 Apr 2008 12:35 am

definitely take the flywheel sensor off and give it a good clean, its very easy to get to on a 1.4 anyway (360 is harder as the heater box has to come out unless you have ultra flexible arms)

Post by **classicswede** » 19 Apr 2008 11:52 am

I've always found acess better on the 360.

The fact that the missfire is worse at idle to me indicates an air leak rather than ignition problem.

Post by **Pappa** » 19 Apr 2008 11:51 pm

Yes i also thought about an air leak or something like that, but I've replaced nearly all of the vaccum hoses in the engine. However the hose from the fuel filter to the carb appears to leak a little where it mates to the fuel filter, but i don't know if air can get in here and screw things up..

Post by **morgan105** » 20 Apr 2008 11:37 am

If you have a leak in a fuel hose it can suck air in and cause running problems, if it gets to big a leak the car could also refuse to start.

Post by **jtbo** » 20 Apr 2008 12:08 pm

classicswede wrote:I've always found acess better on the 360.

The fact that the missfire is worse at idle to me indicates an air leak rather than ignition problem.

Yes, at least in Mk3 it is quite ok to access, two bolts and then just pull it out, don't know how it is different in 340, but I would think it is similar job.

Is carb base warped, or did that happen on 1.4 too?

To check that one needs to remove carb, check with ruler surface that is against manifold, it should be absolutely straight so that there is no gap at all when checked with ruler.

Post by **Jason B** » 20 Apr 2008 11:35 pm

If its useful - Flywheel sensors across the range are exactly the same, the change in part numbers only dictates the length of cable they have. 1.4 340 and all 360's are the same, 1.7 340 apparently has a different cable length.

Post by **Pappa** » 21 Apr 2008 03:04 pm

Well i think my sensor is just fine. It looked clean, and measures 222 ohms with an ohmmeter (spec says 220 ohms +/- 60). It's just a black plastic cylinder with a very small protruding tip right? Nothing more?

I think the problem might be an air leak like classicswede says. Gonna change every hose, air/fuel filter, new exhaust from the manifold and recondition the carb and see how she goes.

... edit

And I just played around trying to find vaccum leaks and i think there might be a leak where the carb meets the intake manifold. The area around the two bolts nearest the rocker cover is kinda wet. Also spraying WD-40 or similar here revs the engine up.

In addition the studs to mount the carb here was loose giving me a hard time getting the mounting nuts off. So that's probably why it's been sucking false air. The gasket seems fine.

I'm gonna try taking the studs out and putting epoxy steel down the holes and screw the studs back in and see how it goes. I'm having a hard time cleaning the outside of the carb as the side where the gas hose goes in is packed in greasy dirt (used to leak around the gas inlet). If anyone has any tips on getting this crap off please let me know.

Post by **Pappa** » 22 Apr 2008 09:05 pm

According to Haynes the float height should be 7mm from bottom of float to top of gasket when holding the lid upside down, but green book says 22.7mm from float centre to mating face of lid. Are these pretty much the same?

I replaced the float, needle and seat and stock it's at 7mm from bottom to gasket, which is what haynes says, so i guess it's okay stock then?

And getting the choke lever back on with the spring correctly is impossible

Any tips?

Post by **Pappa** » 28 Apr 2008 05:25 pm

Well everythings sorted, still sucking air somewhere it shouldn't. Wonder if it could be the intake manifold. This is driving me crazy.

Post by **morgan105** » 01 May 2008 02:44 am

Is the base plate tight to the bottom of the carb? Screws are located underneath the base to the carb and can come loose and are easily overlooked. And are all the vacuum hoses clean and securely connected?

morgan105

Post by **Pappa** » 01 May 2008 11:06 am

morgan105 wrote:Is the base plate tight to the bottom of the carb? Screws are located underneath the base to the carb and can come loose and are easily overlooked. And are all the vacuum hoses clean and securely connected?

morgan105

Yes, very tight. I also replaced the gasket on it.

All the hoses are new with new clips except the renix one, but if i plug the hole to the renix on the carb with my finger and spray carb cleaner it still revs up, so i guess the leak isn't there.

I think the manifold may be leaking, it's pretty much the only thing i haven't tried to tighten the nuts on. Long shot but i guess it's possible.