Surging at speed

[David24]

Before I start off, I couldn't for the life of me find anything about my problem. So here it goes. I got a '95 Eclipse RS. No turbo. It will randomly surge while cruising in 2nd gear or higher. I've tried everything short of playing with the ecu. Replaced fuel filter, plugs and wires, o2 sensor, cleaned fuel injectors and it also has appropriate fuel pressure. I've also taken it to the dealer and they didn't find anything. This problem is very intermittent. I can't stress that enough....it happens at the most random times and sometimes it will not surge for months then will come back. A couple times it felt like it was running out of gas.

I've tried everything within my capabilities (unless there is a simple task I forgot to mention) so I'm wondering if I should try a different ecu. Or is that even possible? Go get one from a junkyard and plug her in.I'm just about to the point to stop trying to diagnose the problem and wait until something fails.

 

[Night devil]

I would check the alternator and the coilpack. My friend had close problem with his non turbo, and it ended up from his coilpack. Ran alot better after, two months later his alternator start doing the same when it was getting weaker. He changed it after and it ran good for a year till he sold it.
Hope this helps and good luck.

 

[David24]

ive already checked the coil pack but i will do it again for good measure. ive also replaced the alternator about a year ago so its still basically brand new

 

[Night devil]

I replaced a new alternator from the dealer, maximum 2 months it was bad. Had to wait little longer for another one. Also depends if oil spills on it, kills it faster. But, check the condition of the coilpack mostly from it, and if you can check the alternator also why not you know.

 

[David24]

well i just checked the coil pack. on the side terminals im getting zero resistance and on the plug wire terminals im getting 12.5 resistance. the haynes manual says .5 to .6 for the side and for the terminals between 11k to 13k. i tested with my volt meter set to 20k ohms. im not really sure about all that though.....

 

[David24]

Well I'm still unsure of my specs of the coil pack. I picked up a couple coil packs at a junkyard but didn't realize that the pins were different in the connector.

Does anyone else think my problem is due to the coil pack going out? I read somewhere that the insulation just wears out and then the fact that resistance increases with temperature makes me think it's the coil pack.

 

[boost97gst]

Ok, this is a long shot but i had similar symptoms on my 98 rs. The egt runs awfully close to some wiring. You can guess what happened, a large (white iirc) wire was very rarely htting the egt pipe and grounding, but not enout to pop a fuse. Funny thing was, it would suddenly miss just randomly and stall out but very rarely. Then the frequency of the problem increased until i popped one of those heavy 40A fuses. Thats when i figured it out and dug around under there. Belayed the wires properly and insulated them. Not a peep out of it til i sold her at 225k miles.

Its just one trouble spot that all 420a's had. If its not your problem i figured you should still be aware of it.

I was going to ask if it seems to happen after it rains, but your in washington so i guess thatd be about every other day . Coil packs dont like high humidity when theyre going bad. I would start looking through your wiring if i were you. Reconnecting plugs and checking for worn areas.

 

[David24]

I will look into that this weekend. I'll check just about anything right now. This problem has been haunting me for almost two years.

And yes it does rain quite a bit but we're in our summer dry spell right now. But now that I think about it, it seems like my car likes to surge during our warm months. It's been fairly warm and sometimes hot (like 90-95) a couple days and that's when the surging was at it's peak. Same time last year too. And if I drive it long enough it will start to do it (assuming the under hood temps climb while driving)

 

[David24]

Ok what is this "EGT" you are talking about? Is it a part on a turbo set up? Because I don't have a turbo.

I just bought a new coilpack so I'll have to see what that does when it gets here in the mail....