Expert: Dan Liddy - 9/24/2009

Question
Hi,

I have been troubleshooting my sons car for about 2 weeks now. Still can't find answers. Several mechanics are as baffled as us. In researching I found one of your posts so I hope you can help.

Background. Car: 95 Acura Integra B18B1. Head, Intake and Exhaust: 1.6 Honda Civic Del Sol Vtec.

My son had this car for 2 weeks not problem. First, it started running a little "off", possibly misfiring, only under heavy load (high Rpms).  About a week later it starting running rough. One cylinder did not have combustion occuring. Checked Injector, no change so changed injector. This worked. Approximately 60 miles later, it happened again. Same cylinder (#3). Changed injector again and fixed. For short time again. Then, son found loose sensor on Intake. Fixed sensor and fixed car. Short time again!

Starting rough again. Misfire on cylinder #2 and #3. Son unhooked all injectors, Swapped 3 with 4 and 2 with 1 (inside to outside) put all back together and it fixed it. Drove hard (high rpm) about 15 minutes and it happened again. Unhooked and removed injectors again and put back. Fixed it again!

not sure at what rpms problem starts, but from putting miles on it myself, if you never go over 3000 rpms, no problem, I drove it for 2 days just to prove a point I was trying to get across, grin.

BTW: has new intake/head/exhaust gasket. And we have perfect compression at 165 across the board.

Seems as though something is maybe signaling a problem to the ecm at high rpms and it resets it when we take everything apart??

When the problem happens, the injectors are all ticking and there is fire to the cylinder. So don't understand why we lose the combustion.

Any help would be greatly appreciated!

Thanks,
Angela

Answer
My short answer is "I don't either" .  I had some baffling EFI problems with another son's Nissan Max, and finally took it to aguy who agreed to make a 'spare time' project out of it.  It took him a few days to discover that the front pully we had installed (an underdrive pully) had come set up to fire a 4 cylinder and that was why we couldn't get the other two to fire. All he had to do was change the trigger magnets and it was fine. This was AFTER I spent $700 on a remanufactured ECU- - -you can imagine how I felt.

In a word Angela, if I can't find the problem with an EFI system right away, I send it out myself.

I can build race motors, race cars, weld roll bars, fabricate neat stuff to mount your fuel cell, and stuff like that.  The electronic gadgetry sometimes leaves me talking to myself.

Sorry I don't have a better answer ! I wish you the best of luck !!

Dan Liddy
Sarasota, Florida