B18FT wont accelerate on boost

**Phil B** · Saturday 29th October 2011, 17:21

Ive just completed a B18FT swap on my 440 (previously b18u) and all is well. However, when using my MBC to wind up the boost, it will accelerate hard up to about 3.5k/rpm then it seems to really struggle to pick up at all after that and the boost drops off by a couple of psi.

Ive changed the fuel pump for the 4 bar out of the turbo, but none of the wiring or relays. Also, when i did the swap i had to swap the dash wiring loom which ment bypassing the immobiliser and wiring a direct switch to the starter, the fuel pump doesnt prime with the ignition and only runs when the engine starts, and seems a little noisy. is it possible the immobiliser is preventing the fuel pump from running properly?

Im pretty sure its a fuelling problem, the turbo is producing plenty of boost. What is the normal running/full boost fuel pressure supposed to be on this engine? i could do with testing it to see if its getting enough fuel on boost.

its really bugging me that it picks up so well up to 3.5k then just goes flat and sluggish.

Any help appreciated, Thanks

**Phil B** · Sunday 30th October 2011, 14:25

Bit of an update, refitted the standard boost regulating valve and its boosting straight up to 0.5bar and dropping off to 0.2 again, theres quite a sharp drop off in power at 4krpm and its using a hell of a lot of fuel. Also its cut out a few times at idle while ive been working on it today.

Took a friend out in it today whos an auto electrician and mechanic and he seems to think its an ignition system problem, either the plugs (new set already ordered) or the coil breaking down, or a connection in the distributor.

Alternatively i think it could be an air leak somewhere but i cant find one.

Any thoughts?

**T5frankie** · Sunday 30th October 2011, 14:57

not many owners of these cars on here mate generally a t4 or t5 forum

**smithy** · Sunday 30th October 2011, 15:18

Originally Posted by t5frankie

not many owners of these cars on here mate generally a t4 or t5 forum

and 1 940 lol

**T4Rick** · Sunday 30th October 2011, 15:40

Originally Posted by Phil B

Bit of an update, refitted the standard boost regulating valve and its boosting straight up to 0.5bar and dropping off to 0.2 again, theres quite a sharp drop off in power at 4krpm and its using a hell of a lot of fuel. Also its cut out a few times at idle while ive been working on it today.

Took a friend out in it today whos an auto electrician and mechanic and he seems to think its an ignition system problem, either the plugs (new set already ordered) or the coil breaking down, or a connection in the distributor.

Alternatively i think it could be an air leak somewhere but i cant find one.

Any thoughts?

I dont think the fuel pump is the problem.As for the imobiliser id remove it all completely,alsoid check the wiring from the fuel pump upto the fuel pump relay as well.I remmeber doing a mk2 fiesta turbo conversion and i had to graft a loom into the car and i got two wires wrong and it just primed constantly instead of cutting off.Do these cars have a maf?any pictures of this car?

**Phil B** · Sunday 30th October 2011, 16:32

The fuel pump doesnt prime with the ignition it just runs with the engine running as the wiring from the ignition switch goes to this immobiliser unit, could it be that its not getting the proper signal from somewhere and just priming constantly as you said? what were the symptoms when you drove the car like that? the pump does make a constant quiet high pitched whine when running.

Thanks

**T4Rick** · Sunday 30th October 2011, 17:50

Remove whole imobiliser mate and go from there.Some alarms are designed to cut fuel as well.Keep us up dated.I didnt get a high pitch noise i didnt run the car long because i didnt like the way it went lol.I stripped back to basics and started again and eventually got it right

**Phil B** · Sunday 30th October 2011, 17:57

I was afraid of that, the wiring to and around the immobiliser is a mass of wires going all over the place, looks like a right pig to sort out

Just been out fiddling with it and it seems like theres an air leak somewhere so i suspect that may be causing it, i cleaned out the idle control valve and now its ticking over at 1800rpm and occasionally hunting at regular intervals. seems like thats likely with the boost dropping off and the increased fuel consumption.

Thanks for your help, ill keep updating as i go along.

**T4Rick** · Sunday 30th October 2011, 19:51

Originally Posted by Phil B

I was afraid of that, the wiring to and around the immobiliser is a mass of wires going all over the place, looks like a right pig to sort out

Just been out fiddling with it and it seems like theres an air leak somewhere so i suspect that may be causing it, i cleaned out the idle control valve and now its ticking over at 1800rpm and occasionally hunting at regular intervals. seems like thats likely with the boost dropping off and the increased fuel consumption.

Thanks for your help, ill keep updating as i go along.

If its hunting you defo have a leak some where,id remove all the alarm wires and solder the originals back up for time being.Id get a idle control valve from a n/a model as there be less chance of it being bunged up.When you say its ticking over at 1800rpm im guessing that this is with the choke stuck on?.If it is its a very common problem and i replaced mine today because i had the same issue

**Shadow** · Sunday 30th October 2011, 20:20

the fuel pump on my 480 turbo does'nt prime when you put the ignition on. that's the way they all are none of the 400 turbos do the pump only run when the engine is turning. makes them a pita to start if you leave them parked up a while.

**T4Rick** · Sunday 30th October 2011, 20:26

Originally Posted by Shadow

the fuel pump on my 480 turbo does'nt prime when you put the ignition on. that's the way they all are none of the 400 turbos do the pump only run when the engine is turning. makes them a pita to start if you leave them parked up a while.

Thats not a good set up lol.When i had my 440 n/a years back mine primed then stopped

**Shadow** · Sunday 30th October 2011, 20:59

yeh it is a stupid set up all 400 NAs prime the pump when you turn the ignition on but the turbo one's don't. don't know why but then again the 480 turbos have 2 ECU just to run the engine one to run all the interior electrics and the ABS ECU it mounted it the boot for some stupid reason.

**T4Rick** · Sunday 30th October 2011, 22:10

Originally Posted by Shadow

yeh it is a stupid set up all 400 NAs prime the pump when you turn the ignition on but the turbo one's don't. don't know why but then again the 480 turbos have 2 ECU just to run the engine one to run all the interior electrics and the ABS ECU it mounted it the boot for some stupid reason.

An abs ecu in the boot lol now thats different

**Phil B** · Sunday 30th October 2011, 22:25

Originally Posted by 850Rick

If its hunting you defo have a leak some where,id remove all the alarm wires and solder the originals back up for time being.Id get a idle control valve from a n/a model as there be less chance of it being bunged up.When you say its ticking over at 1800rpm im guessing that this is with the choke stuck on?.If it is its a very common problem and i replaced mine today because i had the same issue

Im not aware of a "choke" system on this engine, so i couldnt say but now you mention it that does sound plausible, that would explain the overfuelling. Is it possible the icv is sticking and allowing a boost leak under load? I dont know what the common issue is with rhe icv on these engines

**T4Rick** · Sunday 30th October 2011, 22:30

Originally Posted by Phil B

Im not aware of a "choke" system on this engine, so i couldnt say but now you mention it that does sound plausible, that would explain the overfuelling. Is it possible the icv is sticking and allowing a boost leak under load? I dont know what the common issue is with rhe icv on these engines

The icv is very common across the volvo range Phil from what volvos ive had any way.I wouldnt say your car is leaking boost because of the icv but i do no it will drink fuel lol if the choke isnt working to full effect.Engine conversions are a pain in the ar*e ive just converted from 2.5 n/a auto to t5 manual with an r ecu which i managed to savage from the scrapyard lol.I no what your going through mate but bare with it

**Phil B** · Monday 31st October 2011, 19:03

Sounds like a good project

Ill look into the ICV problem another time as i dont think its causing the issue im having.

Been pondering on this again today and i have to conclude that because the donor car ran perfectly for the 300 miles i drove it home, that the problem must stem from something ive done wrong during the conversion and setting up. This has led me to the conclusion that somewhere along the line there must be a sensor wire not connceted properly, it seems like the only logical explanation considering the other car ran fine before i pulled it to bits.

If theres a sensor not sending a signal to the relevant place then it wont run properly, so what sensor faults do you think would cause the fault im having? So far ive read that the lambda and knock sensors could directly cause this issue so at some point im going to unplug them individually and see if the problem gets worse or stays the same, any other important ones you think i should check?

**Shadow** · Monday 31st October 2011, 21:03

have you connected the vacuum/boost hoes from the manifold to the EZ210K ECU?

also make sure you got the air flow meter the right way round?

**Phil B** · Monday 31st October 2011, 21:05

The vacuum line to the ecu is fitted and working fine, and the air flow meter hasnt been removed since i took the engine out of the other car and it ran fine before.

Thanks for the suggestions though

**T4Rick** · Monday 31st October 2011, 21:48

What year is your car mate?Do you have a diagnostics plug?

**Phil B** · Tuesday 1st November 2011, 17:58

My cars '96 the donor cars '93, which i believe is too early for an OBD system, if only it were that simple.

Cant work on it during the week atm as i work til half 5 n its dark by the time i get home so i wont be doing any more investigation until the weekend, but one way or another itll be sorted then