RIght,

I bought my car about a month ago.

Its a volvo 340 1.7 but with a F7R.

Couple of quick questions. Should it have a rev limit bounce ??

Because at the moment i get into second, put my foot down, it gets to about 40mph and it kinda does this big jolt and a loss of power. Whys this ??

Also when im going sideways in second it kind of rev's up and then bogs down loads! and then picks up again.

Im told the engine could of been cammed up because its quite dodgy idling, like it constantly wants to die. If its cold, i have to rev it a little to keep it alive, and then its fine.

Anyone know whats going on ?? Should i be able to get past 40 in second ??

HELP HELP HELP

defo should be able to get past 40 i think its 60 it limits the rev limiter should bounce yes and is it on carbs or fuel injection?

Is this the one from Southampton? If so, it was running a Megane ECU which I believe (happy to be proved wrong) no one else here is. I'd suggest it's the better system but a lot harder to get running, as such though things like rev limiters if they exist will likely be different.

Its fuel injection. Im almost sure of that haha.

Ahh i think ive had it past 40 a couple of times when its been running for ages.

Yer it is the one from southampton. What ECU's would people normally run with the F7R'S ?

Its got a mercedes sprinter fuel pump which is meant to put out 4.5 bar, could this be the problem ?

Cheers for the help guys.

Depends on the setup, there is a lot of variation possible.

I run an Evo VI pump on mine, so it's unlikely that, no matter what pressure is going in the fuel pressure regulator if set up right should only allow the correct pressure at the rail, the rest bleeds back to the tank. A bit like 80W speakers only being 80W if the amp pushes that power into them.

Where abouts are you and do you have a video of it running?

Im in Portsmouth.

What i was thinking is that the fuel pump might not feed the engine well enough ?

I could get one for you guys.

The stock FPR is set to 3bar on the clios, so I imagine the megane is similar. Certainly, unless you are flat out up hill at 11squillion revs it shouldn't need it.

I've no idea how possible it is, but diagnostic socket on the loom?

Yer thats the next step. The guy installed a 16pin diagnostic plug in the car. So ima plug it in and see what the score is...

It does seem like something is missing causing a vacuum leak.. ill get a snap.

I spoke to some mechanic and he said it seems like its hunting alot and could be caused by this ???

Could this be the source of my problems ?

hi did you find out what the problem was as my car has started doing this to

Yer my fuel pressure regulator wasn't plummed in :/ Its all sorted now...

Thread revival. Just bought this car back and it still backfiring under load. Anyone know why this could be. Changing plugs in the next couple of days to see if this fixes it

Get some decent photos of your engine bay up, given the amount of random bits that are possible to swap it could be a lot of things.

It's a shame yours is on a Megane ECU, I have no idea how diagnostics on that works. The info is likely out on the net though?

Tried plugging it in before but just threw up a load of random codes. Might see if I can get it redone. It does have a 16 pin diag plug under the dash. It's just proper weird. Almost like it hits fuel cut

Check the coil pack is any good, they are notorious for playing up on the meganes. They break down internally and give a missfire situation under load.
Adam