I've got a 88 Civic 1.5L with dual point injection(throttle body). The car idles fine, and if I accelerate very slowly, it accelerates. But, if I press the throttle quickly, the car bogs down and backfires. I've replaced the plugs, wires, rotor, distributer cap, distributer, and the fuel filter. I've had the fuel pump tested for volume and the fuel regulator checked. I've swapped the entire throttle body and eacv. Nothing has made the problem go away. I've also changed the MAP sensor. Anyone have any ideas of what else to check? Help please.

Forgot to add that I also have checked the main relay as shown in the shop manual. It's fine according to the tests.

 

Battery, alternator and your battery wires going to the main fuse box under the hood. Mine looked fine but were corroded. A resistance test (Ohmeter) shoul do the trick. They should have very very low resisitance if you read more than like... maybe half an ohm then replace them. The ground is cheap maybe 7 bucks but your positive wire is best from the dealer because it will fit perfectly. Up to 50 bucks, talk about getting boned, but the wire replacement is usually a good idea.

 

Thanks. I got bored last night and pulled out the wiring harness in the engine. It included the wiring to the tps, injectors, altenator, sensors, etc. The highest resistance was .09 ohms. I did not check the wires to the battery and only 1 to the fuse box (it was in the harness). I'll check the rest today and see what we get.

 

No joy. All wires checked out and had the battery and altenator tested at Autozone and O'rielly's. Both are good. Any more ideas?

 

Look at the secondary fuel injector. (this problem was written up a couple of years ago in this forum)

 

Replaced the secondary injector with a new one. Still got the same problem. Any more ideas?

 

Double check the wire and all the connections to the secondary injector. Just because you got a low resistance reading doesn't mean enough current gets through the wire and makes the injector work correctly; if there's a resistor pack connected to the injectors, check ohm reading for both resistor; check all the engine ground connections.

Take Care,
ChrisS

 

Especially the transmission ground cable. I've heard horror stories where a loose ground caused bad running conditions. Hundredsof dolars later a scoket wrench solves the problem.

Otherwise... Could your TPS be going bad? Possibly the IACV (Idle air control valve) or even a sticky throttle plate, check for deposits around the flange (round thingy inside the throttlebody)

These are shots in the dark by the way but might help narrow it down some.

 

You just wrote up most of those things, however there should be an injector resistor (if I'm thinking correctly) on the upper driver side of your engine bay. Small box maybe 1 inch deep 2x3 with fins to dissapate heat. I replaced mine and noticed a marked increase in throttle response.

Mechanically, is you clutch slipping at all? RPM's jump when you try to accelerate? Or a strong neck jerking stutter when you stomp on it at speed?

 

This problem sounds very much like a bad ground.


none of these could be the issue.