Hey guys. I recently bought a civic with a jdm d15b vtec swap that wasn't done yet. since I've put in a chipped vtec ecu, new spark plugs and cleaned vtec solenoid as well as gettingthe tranny on and mounting up the exhaust and shift linkage . i got it running now but after vtec the tach isn't reading right? i redline at 8k but the tach still reads in between 5-6k rpm and around 2500-4300k rpm it lags and mis fires until vtec engages. I thought maybe the dizzy is bad? I checked to make its the right one and it is td42u. do i need a new one or could it be something else? Any help would be appreciated

 

What ecu are you running?

 

Chipped.... I would think you have a bad base map and need a tune.

 

you said that you put in a chipped ECU. What ECU did you put in? Also have you tried putting the ECU that came with the car back in? If so, do you have the same issue?

 

Its a chipped p28 from phearable its new so I'm sure that base map is fine on it. the ecu i had in before was an auto ecu. P28 for an automatic as the car was converted to manual. if i put the old ecu in it won't let me rev past 4k and i have a cel. The idle also goes up and down and cold start it revs to 2500 for a bit till its warm. that's the old auto ecu it does that. the new ecu doesn't , and no cel. but i have the current issue of the tach not being accurate after vtec and then the lag and misfire before.vtec. if i drive it normal its not problem but 2500 and i can press the gas all the way down and i can feel the lag. my buddies d16y7 runs way harder. from second gear at 2500 if i step on it, it just acts like it doesn't want to go anywhere and stumbles until vtec and then after the tach is off and idk where the rpms are truly at

 

My civic is also a ex. if that makes a difference

 

The igniter unit may be bad. It supplies the rpm signal to the tach. Also test the coil.

 

Also just so you are aware, you can convert your OBD1 P28 auto ecu into a manual ecu without needing to chip it. The CEL would be on being it thinks something is wrong with the tranny and would go into limp mode.

I'm sure there is something out of whack with your base map. It's a map provided to drive casually to your nearest tune shop and get the chipped ecu dialed into your setup only. It's not really made to be for everyday permanent use. And definitely not made to get on it prior to a tune.

 

Idk. I had a H22 with just a basemap from phearable. ik its not a permanent tune but it still had no hiccups like this motor is doing. I jjust got back from the junkyard, found dizzy from d16z6 there. only 18 bucks so ima see if it makes a difference after swapping it out here in the next few minutes. thank you guys for the responses i really do appreciate all the insight. HT is always helpful. i read about converting the ecu as well before. r17 and r18 and a jumper wire. i dnt know exactly off hand but ik its pretty simple. i didn't find out until i actually paid for the ecu. sucks but watever. lets see wat happens here.........

 

Ok so good and bad news. The good news is, the z6 dizzy in the jdm d15b works fine and no more hiccups, rpm band is smooth all the way till redline, chirped second slow shifting it. Bad news is the tach is still off after vtec. The tach doesnt go up as fast as the engine does. Would that mean the cluster just needs replaced then?

 

How do you know it's off? Video?

 

I'll make a video later today and post so you see what i mean. Im at work now so in a few hours ill put something on youtube and put the link

 

 

Tach ?? Anyone can clarify so thread can be closed

 

Video has been removed.

 

Put up a vid. Just a roll from second gear to redline. Tach says 6k but ecu was chipped for 8k and it does sound like its reving to 8000

 

I don't see a convincing tach problem. I hear misfiring near 6K rpm.

 

Misfiring? hmmmm.. I guess new cap and rotor, spark plug wires. maybe fuel filter too. i swear it sounds like a rev limiter.I'm doing over 60 in second its an si tranny. at 6k i should be around 50 mph i thought

 

Well i was messing around looking at the car and i remembered that the ground to the tranny i left unhooked. It wasn't long enough i had no where to put it so i left unhooked since my car still started and drove. Could that possibly be it? Im jus gonna get a longer wire same gauge and see if it makes a difference.

 

Connect the ground properly.

 

So, i connected the ground to the tranny, changed the cap and rotor, also changed fuel filter. Cant say there is no difference, its minimal. Still same thing, same rpm it cuts out. My mechanic told me that the fuel pressure regulator could be bad or i need a new and upgraded one, that it causes issues similar to my situation. Does that sound right? I was going to get a new fpr but wanted your guys opinion first. I need to get it at least running right before i can get this thing boosted. help?

 

also to add, i read the the tps can also cause hesitation and misfire as well if its going bad. i guess my only other leads are that and fpr then? Anyone can provide any insight? and can a faulty vtec solenoid also cause an issue like this as well? I cleaned my old one, i can hear vtec engage, but would it somehow cause me to not be able to go above 6k rpm? Im jus stumped rn

 

bump