Cant go over 4000

darkstarsi · Post by **darkstarsi** » Wed Jul 30, 2003 4:32 pm

I have a p28 ecu with s200
on my 95 prelude vtec turbo
the ecu wont let me go over 4000 rpms.
also when hooked to computer the system cant connect
chipped wrong?
i put in old p14 ecu(non-vtec) and car goes to redline
whats the problem?

hack · Post by **hack** » Thu Jul 31, 2003 7:51 am

somebody please answer this guy... i have the same thing. '97 gsr with obd2b car is supercharged and is programed with a gm 3 bar map sensor. after improperly connecting the map i got it straight (after a new one cuz the original had been harmed somehow) now all conditions are correct ignition timing , vacuum , every apparent elect hookup. i'm now on my second chip programed for a 30 % incease in fuel across the board and it still shuts down and goe all the way lean at about 4000. i really believe it's more due to the throttle position - either the sensor or the fact that when open enough it's letting in more air til it says no way.
i'm getting a third chip with it programed for even more fuel to determine if it's even the fuel map at all. the car has jg 65mm tb which came with the tps (suspect) a skunk2 intake which removes the second set of runners , rc 440 injectors , vortech sc , msd sci plus , dc header and it is a manual shift. help

AndyE · Post by **AndyE** » Fri Aug 01, 2003 1:19 pm

If you're experiencing a fuel cut at 4000 rpm, then you almost certainly have a communication problem between the ECU and the Hondata interface box. This will likely be accompanied by a flashing LED on the interface box and a solid CEL, as well as a fuel cut if your manifold pressure goes above ~1 psi of boost. This is commonly known as "limp home" mode.

This is usually caused by a ROM that's inserted backwards, an incorrect ROM for the type of ECU you have, or a version mismatch between the ROM and the interface box (version 2.5 vs. 3.0). Less likely but also possible is faulty wiring between the ECU and interface box.

(Hack - you say your ECU is obd2b, what do you mean by this? A Hondata-powered GSR should be using an OBD-I ECU. Are you perhaps talking about a *stage* 2b? Just trying to clarify.)

-Andy

hack · Post by **hack** » Fri Aug 01, 2003 7:03 pm

yes sir thankyou for the evaluation ! that's exactly what it's doing ''limping home'' ...a very sharp cut in fuel right around 1 lb of boost and it feels like the ignition was cut right in the middle of an accelleration. my hondata ecu box says obd2a on the side.....just found that today ...so the interface box is wired wrong or something ? it's blue and about 3'' x 4'' with an orange , red , and black wires (3) coming from it.
please tell me what to check !!!!
hack

QUICKSILVER RACING · Post by **QUICKSILVER RACING** » Fri Aug 01, 2003 8:24 pm

TRY READING THE MANUAL FIRST.

hack · Post by **hack** » Fri Aug 01, 2003 10:15 pm

you know .... if i were programing my own hondata i'd most certainly have many problems....like not knowing how to do it ! fortunately i have a guy doing it FOR me.... he's in NY and i'm west coast i don't have a manual to read and wouldnt know what to do about it if i did.... i'm out here , and i'm trying to figure out what i can about what the cause of this is . i DID already screw up a 3 bar map by wiring IT backwards and i'm wondering if that may have something to do with the interface - like burning it in some way. you guys are a valuable resource for tech information !
thanks hack

QUICKSILVER RACING · Post by **QUICKSILVER RACING** » Sat Aug 02, 2003 2:11 am

I am not being rude. The best way to learn about it is to read the manual and discuss it here. You can read and download the manual in the Download section.

It is important for you to know everyting about it.

I am pretty sure there is a Hondata Dealer within 30 mins from your house.

It would be worth it when you know everything about the product.

hack · Post by **hack** » Sat Aug 02, 2003 8:51 am

ok thanks THAT IS CONSTRUCTIVE i thought you might be on my case. so just for laughs....what is it that causes the fuel cut like that ? it seems to me that would be a rather basic thing to get straight and mine is programed by a 'pro' who should know better.

AndyE · Post by **AndyE** » Sat Aug 02, 2003 9:00 am

My post above describes all the major causes of limp home mode. Have you checked the items described above?

hack · Post by **hack** » Sat Aug 02, 2003 8:33 pm

ok my ecu is P28 OBD-1 2a i guess is the fact that it can read boost ? anyway i'm definetly checking to see if the ROM is in correctly - and as i recall the interface has a red light always on...i thought that was normal...not blinking though. also remember i wired my map wrong the first go 'round and got another , but i'm still afraid it did something to the interface....is there a voltage i can test for to see if it's hurt ? let me know if there's something i can look for....my guy is checking into it too , monday. it is programed with version 3.0

hack · Post by **hack** » Sun Aug 03, 2003 8:51 am

what does CEL stand for ?

AndyE · Post by **AndyE** » Sun Aug 03, 2003 4:22 pm

Check engine light.

hack · Post by **hack** » Sun Aug 03, 2003 5:05 pm

yea of course it does.... it's been on since i started , i've not looked up a code in a long time. drove it a little today...not rpm related , but more boost related like you said. here's a small question....there was some concern that the o2 sensor to the ecu wasnt functioning ... so i put the second one in its place which came out when i went OBD-1 .... ARE THEY THE SAME ? it plugged right in , but i don't know if it's wired the same. answer ?

QUICKSILVER RACING · Post by **QUICKSILVER RACING** » Sun Aug 03, 2003 6:16 pm

MY guess would be to check if the boost function was enabled in the interfacebox.

hack · Post by **hack** » Mon Aug 04, 2003 9:19 am

boost function enabled in the interface box.... is that something programed into the ROM or is it something i can check on myself ? can voltage be checked on the interface connection ? what about that o2 sensor ? the same ?? it's monday here 9 am..... my guy is checking on what the fuel cut off could be....he has me programed to see up to 15 psi.
i'm checking to see if the ROM got put in backwards today - i just used the serial #'s , but now i know there's a mark on one end that goes toward the ecu plugs. sure would like to know if there's anything i can check about the boost interface....the wires were already coming from the ecu when i got it , and there was only one port that would receive the plug on the blue box......seemed foolproof.