EF Hatch / D15 Died – won’t start

My 90 Civic DX Hatch died on me while driving, check engine light came on. Wouldn’t start back up till it sat for a bit AND I had to disconnect the TPS. I had to tow it home after several more stalls. Started checking under the hood. I pulled a plug and I’m not getting spark. I pull the distributor cap and it smells like something definitely fried. I still had an older distributor so I put that back in. After cranking a few times to see if it would fire up. It did not, also the old distributer now smells like something has burned. I’m starting to think there is something seriously wrong in the electrical that is causing my TPS and Distributor to fail. I had a pulsing light issue and was going to replace the alternator anyway. I’m sure the voltage regulator was going out. It was only producing 12.9v with the motor running… sooooo I replaced the alternator.

On to the engine codes…

I got two upon first failure. The ECU is coding the TPS and the coil. I have DPFI with horizontal throttle body, which means right hand mount TPS. For any of you who know, this part is nonexistent – Honda never sold a TSP for the DPFI as a standalone and whatever aftermarket products there were 20 years ago, they’ve dried sense. If you needed to replace your TPS through Honda, you had to buy a new throttle body, also no longer available. So I ordered a replacement TPS through a source I found on line for $129.00 and also I checked my coil. I recently replaced the entire distributor (with NEW) so I thought it odd that the coil would fail. The forums say check for continuity across pos. (+) and neg. (-) terminals. Apparently my coil is fine, it passes a current with no issue.

So to date the things I have tried to correct this problem are:
1. I replaced my TPS (this makes the 3rd)
2. Swapped out NEW distributor for older known working distributor.
3. I replaced the Alternator (This took care of a pulsing headlight and instrument light problem I had)

I took the car to my local mechanic and he was able to get the car running again. He replaced the coil in the older distributor and it fired right up. Now running with new TPS and coil but there is something wrong. At 3k rpm or higher the motor starts to stutter and miss. Also my tack is jumping all over the place under load above 2500 rpm. That’s usually related to a voltage spike, dirty or corroded grounds or a failing coil – so I’m told. So last night after more tinkering, cleaning all grounds and searching for more clues. I took the car around the neighborhood to see if I had solved any issues. To my surprise the car ran even worse than before. I turned around after only 4 blocks and when I gassed it to come back the motor stalled and died and I couldn’t get it started again until I disconnected the TPS. It drove like crap back home and now it sits in my driveway. The check engine light came on again but I forgot to check the codes before writing this post. I'll check them tonight and update.

I don’t know what else to do. My mechanic friend is a great Chevy, Dodge, Ford truck mechanic but small older import cars… I don’t think he has a clue how to proceed from here. I need Honda Gold tech help here!

 

Tach bouncing is definitely electrical related going to the distributor.
If messing with the grounds had an impact, and in your case it was worsened, then you can make the assumption that you touched wires somewhere that aren't quite right.

To rule out ground issues, take some heavy gauge wire or a set of jumper cables. Hook up direct from the '-' NEG post on the battery and the other end to the distributor. Hook up from the '-' NEG post on the battery to the chassis of the car somewhere. Last, hook a wire from the distributor to the ground wires on the thermostat housing. See how the engine runs like that.

 

I was going to say grounds too. What kind of condition are the ground wires in? Did you clean the ones on the battery, transmission, chassis and engine? Have you looked at the ECU plugs just for kicks? Moisture can leak in, or a spill on the carpet, could wreak havoc in there.

 

Quick update!

I replaced all grounds with new wire. This seemed to help but I was still experiencing bouncing tack below 1500 rpm when throttle is opened up. Then it would smooth out till about 2200 rpm and then it would bounce really bad and the engine would miss. I ended up replacing the dizzy. I had a lifetimeer so I took it back and it was replaced with new. Aparently something in the lower end of the dizzy went bad. Car runs like a champ now.

As for the TPS issue... I determined that the throttle shaft was warn and the vibration was causing the brushes to wear the TSP contact surface. I opened up the 3 dead TPS I have and each one was the same thing. The after market TPS used a conductive material which once the brushes removed a section, would break the entire circuit = no throttle response. I searched and searched for a throttle body for the DPFI with no luck... then I founs a fellow in PA selling an entire intake on Ebay. I scored the intake for $25.00!!! The throttle body only had about 72k on it and the original TPS as well. This took care of my Throttle body and TPS issue.

I know if I have any more trouble with the DPFI I will be moving to a MPFI conversion and make my life a whole lot easier. For now the car is still original aside from the 3" cat back bolt on. And I'm back to $27.00 dollar fill ups with 40 to 42 mpg pump to pump! I love my truck and all but at only 19mpg... I REALLY love my Honda a lot more!

I hope were all just a little bit smarter for this solution.