OK I bought a 91 civic hb race car this year with no engine. I bought a ZC engine that came from Japan. the guy i bought the car from said it had a Zc in it last and i know it was for sure. I paid to have the engine installed and it runs fine but (its hittin the rev limiter at 6500)its runnin on a pr4, ive been told its for a integra. Ive read it should be a pm6 or pm7 with higher rev limits. BUT they dont work right and i know there both good cause ive tried them in a friends race car and theres in mine and i have the same problem.
The pm6 idles up and down and when i gine it a bit of gas it runs rough and then just goes to full throttle while only a 1/8 to1/4 pedal?
The pm7 idles a bit better but when gas is applied it just dies?
Any body have any thoughts? as the guy that but the engine in moved out west before i got it to the track.
I just bought another pr4 on ebay and the guy put a rev chip in it for 9000 rpm but all it does is do the exact same thing as the pm6:banghead:
Ive opened both up and they look the same except for the chip in the new one.
the pr4 that dont work says on the side 37820-pr4-a60 431-219467AS code on board in side is U1Y-E 02DO1620-1500-1

the pr4 that works says 37820-pr4-ao1 430-101420AC the board says
U1Y-E0 02D01250-1500-0

Now is there a OBDO pr4 and a OBD1 pr4? and i just got the wrong one. if so could i just get the rev chip swaped from one to the other or will i have to get a new chip put in the one thats working.

So sorry for the novel but im lost and hope to have it figured out by thursday.

Ps. if any body knows of a shop near the Toronto area the does swaps please let be know.

Thanks.

 

do you have the engine up to operating temperature? the ECUs have a cold start rev limiter which could account for the 6500rpm limit if it is not warmed up - if the engine is stock, the PR4 won't work as well as a PM7 or PG7 ECU - the PM6 ECU will also not work as well and has a lower rev limit than the PM7 or PG7 - if the PR4 ECU you bought on eBay plugs into your harness, then it is OBD0 - OBD1 ECUs have different connectors and won't plug in - either the PM7 or a PG7 should work fine - sounds like your problems are not in the ECU, as you have proven by trying a known good ECU - do you have any codes showing on the ECU?

 

Thanks for the opinion jlicrx. It made me think and u were right about the ecus not being the problem. The first thing i went to check was the TPS. I read some where that they were riveted on and mine had screws? So i took it off to see what it was about. and found out the the rivet heads were stuck to it witch hindered the adjust-ability. Popped heads of , started car adjusted the tps and it ran great with all ECUs.

So now i have way to many ECUs so i anyone wants to buy 1 pm me.
PG7, PM6, PM5, and PR4 . im keeping the PM7 and PR4 with 9000 rev chip.

 

Took the car to the track this weekend and came up with a new problem. Had the pr4 with chip in car, was fine till i mashed the gas and then coughed and had no throttle responce. the car would idle fine but just bog when gas was applied. I shut the car of and restart and all is fine. when to the pits changed to pm7 same thing. then i tried eazing into the gas had a few coughs but was ok till i drove i deep in to the corner then herd a rev pop and no throttle again.
The engine is fine as long as its not under a load. i unpluged the tps to see what happenes and its the same as when car craps on the track. so im thinking tps right.

So just for ***** and giggles i put the pr4 in with no chip and go start scratch in the b-feature and it runs all 20 laps ( well 19 i got laped cause of rev limiter)

Im thinkin of changing the tps and the fuel pump cause my so called mechanic left the fuel pump runnin the the night before i left and killed the battery ( so maybe the fuel pump is week???

Any thoughts? im open for any thing.