Honda heads..b18 problems

[EP82JM]

Posting this for a mate trying to get his car sorted for him

He has a b18c4 swapped em1 civic coupe

The swap was a bit of a botch job and it has a few problems

No crossover at all

And it has a random limiter at 4500 rpm but only sometimes,other times it won't do it,seems to be once it's knocked off for a few minutes it will then do the limiter for the next few minutes,as if it's a cold protection system even though the car is warm.

So when driving in any gear for a while it will bounce the limiter at 4.5k

Also when on the spot it has a lower limiter,4k for example like the k20s etc have,I didn't think the b series had this?

Any ideas what all it could be?

Changed his Vtec solenoid which made no difference

Tried to run a diagnostic check,car has an obd part as opposed to the old count the flash check,must be because it's a 2001 but when an obd is plugged in to the port it can't communicate,I'd imagine that's another botched part of the conversion lol

Bit of a **** box but would still like to get it going well at least

Anyone any ideas? It could all just be limp mode but don't know how we can find out with no possible diagnostic test.

Thanks

 

[ace275]

Is it a standard honda ecu or aftermarket?

 

[ferrett]

could be oil temp sensor as this allows when warm for vtec to activate so if its not working could cause the limiter as 4500 is round about when oil pressure increases ready for vtec

 

[ferrett]

also should flash a fault code on ecu on pas side floor well

 

[EP82JM]

Is it a standard honda ecu or aftermarket?

P28 rings a bell,would that be right?

 

[EP82JM]

also should flash a fault code on ecu on pas side floor well

Tried that mate

It has an obd connection as opposed to the eml flash check.

When plugged in it cant communicate with the ecu,whether thats down to the ecu being the wrong one for the port due to the conversion or if it has even more terrible wiring.

Nothing on the clocks worked when he got it fue to wiring so all had to be left in to get them working.

 

[moorsojr]

@Kavna knows his way around a B18.

 

[ace275]

P28 rings a bell,would that be right?

That'll be a Honda ecu, but could still have an aftermarket board fitted.

 

[Mont]

I have no clue about the limiter but is the thermostat working ok?

Mine wouldn't cross over to VTEC and it was down to a dodgy thermostat.

 

[Steve]

Crossover on a C4 is at 4500, IAB's open at 5800. When did it last get an oil change?

 

[stuart-civic]

P28 rings a bell,would that be right?

If it is a p28 does it have a b18 map on it? P28 is a d16z6 ecu.

 

[EP82JM]

Crossover on a C4 is at 4500, IAB's open at 5800. When did it last get an oil change?

A few weeks ago,all good that side. I get the feeling its just going into limp mode sometimes but as theres no way of doing a diag check on it I cant figure out why. No eml light on either which id put down to the conversion.

Ill need to double check which ecu is in it as im not entirely sure,the guy made an absolute mess of the wiring side of the conversion,loom was cut abd spliced so id imagine its probably whatever the cheapest option was regarding the ecu.

It was originally a d16 @stuart-civic could the priginal ecu still run the b18c4 and maybe that could be the problem if it hasnt had a b18 map?

 

[EP82JM]

Another thing im just thinking...it will limit at 4.5k as ive said...but it doesnt actually have a high rpm limiter lol,it really is a a **** box! Just revs and revs

 

[stuart-civic]

If the car was originally a d16 then its not an em1, an em1 is an ek vti coupe (b16). It may start with a standard p28 but would run like a pig.

 

[Gaz]

Long time since I had any b-series car but I vaguely remember removing my speedo one time to fit new dials, taking the car for a test drive while there off (as I had also fitted a manifold and wanted to be sure it was 100%) and the car not engaging past 4500rpm. Something to do with the clocks?

 

[EP82JM]

If the car was originally a d16 then its not an em1, an em1 is an ek vti coupe (b16). It may start with a standard p28 but would run like a pig.

Same thing lol its an 01 civic coupe,theyre ***** so I dont know their names lol,just broke a vti one thats why it was in my head.

This one runs dead on bar the obvious no vtec and the random limiting so not too sire,must have a look next time I see it. He sent a video so ill upload it shortly

 

[EP82JM]

Long time since I had any b-series car but I vaguely remember removing my speedo one time to fit new dials, taking the car for a test drive while there off (as I had also fitted a manifold and wanted to be sure it was 100%) and the car not engaging past 4500rpm. Something to do with the clocks?

Thought that myself as tye clocks werent working at all. He got them fixed last week but no change so that was that idea out the window

 

[B20DC2]

P28 ecu don't have an output for the iab solenoid. This shouldn't stop the engine revving. Vtec won't work unless it sees a speed input to the ecu, high enough oil pressure in some engines. This sensor is the one on the vtec solenoid. It also needs the coolant temp to be warm. If any of these are not met it won't vtec.
If ur p28 is running a b18c it probably has been chipped and had launch control. Launch control is normally set around 4000rpm and is only active when the car is stopped. I'd suggest checking all your vss wiring

 

[martybelfastsri]

seen a similar problem with a b18 in a civic turned out to bee a loom problem must have been damaged during removal/refitting new loom sorted it wouldnt vtech ect or communicate with brain

 

[Garethb18]

Refitting a new loom seems like quite alot of work,if this turns out to be the case, itll never vtec lol

 

[Rooneyrocket]

It will Vtec, have faith

 

[B20DC2]

Check your earth is on the thermostat housing. It the earth for the ecu. Seen this cause problems on a civic that some tried a wire tuck n removed it

 

[Garethb18]

It will Vtec, have faith

Haha hope so rooney bai work your magic [emoji1]

 

[Garethb18]

Check your earth is on the thermostat housing. It the earth for the ecu. Seen this cause problems on a civic that some tried a wire tuck n removed it

Thanks lad ill check that its really pissing me off was rooneys del sol today and made me hate the car a wee bit [emoji23]

 

[Garethb18]

Check your earth is on the thermostat housing. It the earth for the ecu. Seen this cause problems on a civic that some tried a wire tuck n removed it

Does anyone have a pic of this?