Hi,

My friend just bought a 1991 civic dx DPFI, bone stock, even had the oem snorkel
The car was slow as hell, and I mean reaaaally slow. I have had 3 dpfi civics EF and they were in much worse mecanical shape but they pulled much harder. Just now we did the dpfi intake mod (took out resistor plate, mesh grill, and the plate over the TB), and installed a cone filter. The car is quite a bit faster but it is hesitating at about 4000rpms, like if it wasnt getting enough fuel (spark plug wires and cap rotor is new). When we reach the rev limiter in first gear, the car doesnt rock back and forth like it should, it just gradually stops accelerating from around 6200 rpms to 6800rpms. I say this because I know the rev limiter is supposed to cut fuel out but it doesn`t seem like theres any fuel to cut.
Does anybody know what the cause of the problem is, fuel filter? fuel pump?timing too retarded?
we just ressetted the ecu and we`ll see how it goes,

thanks for any advices.


Modified by vtec8200 at 3:13 PM 2/27/2007

 

change the fuel filter if it hasnt been changed .... how many miles on the engine?


also take the pugs and wires off check the plugs see what condition there in, also chekc to see if the wires are pluged into the cap and are locked onto the plugs

 

ok a little update, I advanced the timing on the distributor and the engine felt much stronger but in 3rd gear, the car accelerated fine from 60-90 km/h, but at a 100, the car stops accelerating and hesitated, even if he keep his foot down for 5 seconds, the car doesnt accelerate...he will check and reset the timing as soon as he can!
its his first honda. Hes had a 300zx 88, eagle talon 95, volks 90, and now he loved his honda like crazy, he regrets not buying one sooner and he used to absolutely hate civics

 

i would change the fuel filter then check your fuel pressure. if it is good, check the timing

 

Well it sounds like a fuel problem to me. I would pick up a new filter. Then I would check your plugs + wires. Could even be something as small as your air filter...

 

Air filter is fine.
let me brake it down a little more:

1000-4000 rpms, its slower than its supposed to, but accelerated smoothly.

4000-4500 rpms, car hesitated a lot, feels like its on every revolution of the engine. If we`re in third gear, the car wont even accelerate past 4500 rpms

4500-6000, feels very sluggish, almost no acceleration but less hesitation.
After another ride, I noticed we couldn`t even reach the rev limiter. Not even in first gear.

tonight, I will try putting my spark plugs from the beater, aswell as the wires, fuel filter and distributor, we`ll see how it goes.

 

BTW by hesitating, I mean that it feels like the car skips 1 explosion out of 2 at 4000 rpms. Kind of like an MSD spark controled rev limiter at very high rpm, know what I mean?

 

sounds like timing might be off

 

hope its just that.

 

tonight I put spark plug wires and spark plugs from my beater since I know they work. First thing we noticed is that the wires weren`t put on the correct firing order. it was 1-2-3-4 instead of 1-3-4-2 (or something like that, used the search function to find the correct order).
That took away a little clicking sound there was at idle. Im surprised the car ran fine with the wires put on incorrectly. It helped a little, but didn`t take away the hesitation.
Since I advanced the timing (twisted the distributor towards the firewall) yesterday, I tried twisting it towards the radiator. That made a big difference, the car has much more torque, and accelerates smoother, but in third gear at around 110 km/h it still stops accelerating all of a sudden, like if it was pinging (or pinking?...detonation). I`m almost certain thats what its doing. So my guess now is that the timing is way too advanced. Any opinions?

by the way the cap rotor and dizzy looked new on the inside.