Help! 1993 Honda Accord Surging. Honda shop cannot find problem.

[noah123]

My car is a 1993 Honda Accord running both Benzine and LPG. In the morning when I start the car it's fine, but after 10min of driving the check engine light comes on, then the engine shudders/surges. If I give it more gas pedal it smooths out, but if I let off slightly it starts to shudder again, if I let off all the way it idles down smoothly but shudders hard when going slow. It's like a bucking horse it shudders so hard.

I took it to one shop, I thought IAC valve, he removed it and cleaned it but same problem, they couldn't figure it out and suggested I take it to Honda shop. Honda in Lomsak, couldn't find the problem so they had a 'pro' (i use that term questionably) come from Phetchabun. He said it's the computer ECU. They got a 2nd hand ECU and tried it, still same problem. No they're saying it's a very old car so I should replace the engine or get a new car.

For anyone reading this, the 93' Honda is known to be easy to repair and keep going for many many miles...what gives?

Everyone I spoke to the first claim they make is 'you have a problem because you use LPG.' I really feel the petroleum company started a rumor that LPG is bad, so I disagree with the automatic LPG bad guy assumption. Either way, when I switch to Benzine or LPG I have the same issue.

At this point I'm struggling to get Honda to put my car back together. They said now it also has a leak...WHAT? It had no leak before I took it to them, now can I even drive my car away? They've had it for 1 week already.

Could it be possible that the switch for LPG to Benzine is broke and quickly switching on and off causing the shudder?

I'm not a mechanic, and I'm also on a fixed income, hence my buying such an old car to begin with.

Please, any help is greatly appreciated.

thank you in advance

[CharlieH]

Moving to MOTORS forum for better response

[IMHO]

Has it been on LPG for all of it's 21 years?

If so, it sounds like they've given you the right advice (change the engine).

[ozsamurai]

1. They would have checked your car's ECU, not the ECU that controls the LPG. Have a look at that as well. Honda will not be able to do this, you would best get it to the manufacturer of the LPG system and get diagnostics run. It may be a setting fault, overfueling etc. They do need maintenance every 2-3 years.

oz

[Ace of Pop]

Honda is renown for reliability, but they, like most dont like their product modified by nit wits.It wasnt made to run on rubbish.My Mates Benz has gone the same route.

[BSJ]

My first one back in Oz was the same year, but it wasn't on gas. Never any problems for me or the eldest daughter who I gave it to.

[seedy]

My car is a 1993 Honda Accord running both Benzine and LPG. In the morning when I start the car it's fine, but after 10min of driving the check engine light comes on, then the engine shudders/surges. If I give it more gas pedal it smooths out, but if I let off slightly it starts to shudder again, if I let off all the way it idles down smoothly but shudders hard when going slow. It's like a bucking horse it shudders so hard.

Does it do this on gasoline, or LPG, or both ??

[stevenl]

My car is a 1993 Honda Accord running both Benzine and LPG. In the morning when I start the car it's fine, but after 10min of driving the check engine light comes on, then the engine shudders/surges. If I give it more gas pedal it smooths out, but if I let off slightly it starts to shudder again, if I let off all the way it idles down smoothly but shudders hard when going slow. It's like a bucking horse it shudders so hard.

Does it do this on gasoline, or LPG, or both ??

From the OP "Either way, when I switch to Benzine or LPG I have the same issue.".

[noah123]

I want to thank the OP for moving this topic, as well as the various replies.

Tomorrow they are supposed to be getting in a 2nd hand ECU. Apparently the 1st one was for a F22A engine, mine is F22B. The one they will get tomorrow is for an F22B. Assuming they change it tomorrow I'll let everyone know if this fixed it or not.

And yes, whether I run LPG or Benzene same issue. However, if tomorrow its not fixed I'll be taking it to an LPG shop to have the LPG's ECU checked as a previous poster suggested.

The fact that its an automated switch from Benzene to LPG once the engine warms, and from a cold engine start the problem doesnt happen until around 10min after the engine has been running, would suggest to me its a bad LPG switch/ECU turning on and off.

Again, I'm not a mechanic, just guessing and going off input from those on this forum with much more experience than myself.

I'll let you know what happens when they change the Honda ECU. Hopefully my experience with this might help someone else.

Thank you again

[inzman]

Check your TPS, easy check easy fix. Sorry, it's throttle positioning sensor.

[Ace of Pop]

Dont hold Your Breath, its nackered. Hope im Wrong though.

[BSJ]

"The fact that its an automated switch from Benzene to LPG once the engine warms, and from a cold engine start the problem doesnt happen until around 10min after the engine has been running, would suggest to me its a bad LPG switch/ECU turning on and off. " Maybe. Normally the engine will be warmed up in 3 or 4 minutes.

[seedy]

Check your TPS, easy check easy fix. Sorry, it's throttle positioning sensor.

You beat me to it !!

Because it happens on either fuel, my first culprit.

[noah123]

Crazy, this morning they call for us to bring in our car to change the ECU. We did not drive for 2 days. The car drove perfect for 30min. We stop to get benzene, start the car, the engine light came back on and its surging hard again. The Honda shop changed the ECU, took it for a test drive, its as if the car is fixed. Turned off the car, turned it back on, the problem is back. ECU did not fix it, this is crazy.

Its almost like a temperature issue it seems, at least to me.

By the way, they said they checked the TPS already.

I really hope they know what they're doing. Today again they sent their 'pro' from Phetchabun.

[Ace of Pop]

Strange you got any cooperation from Honda, they dont like aftermarket stuff. Overheating was the prob on mates Benz.Might find the valves are burnt out.Benz wouldn't even look at his 6 Cylinder, and now hes had to replace the unit .Interesting post, good luck.

i

[noah123]

Thanks I appreciate it, the 'pro' they sent seems quite nice.

He said, now they think the IAC is getting hot causing the solenoid to malfunction.

On a sidenote, He also said the engine is not from Thailand. I assumed that already as its a 1993 Honda Accord with an F22B motor and a Vtec head on the engine.

[noah123]

Latest update.

Okay, they said car fixed. I drove with mechanic no problems. I then said, I still think my old computer is okay.

After speaking with him a while I think he wanted to pacify me. He said okay we'll put your old computer back in. We drive it again no problems, he's stumped. We stop, and turn it off then back on, no problem. Just before we get back to the shop we turn it off then back on. ..boom, it has problem again.

He was so happy, he said it's the computer.

We change back to the other computer, problem is gone.

We go to the store 10mins up the road. Finally, getting some foreigner food. After shopping back out to the car and boom, same problem.

We go ahead and drive to get more LPG with the car surging and check engine light on. I turn the car back on, no problems. We drive 30min, get home. I used LPG halfway and benzene halfway no problems. I put the car in park and the Tachometer starts bouncing but no engine light. I switch to LPG it quits bouncing. I switch back to benzene and the tach is bouncing then smoothed out.

I don't understand this and I feel like I just paid for a computer I didn't need to replace.

[kartman]

Get them to put another coil on the car and see what happens.

[Ace of Pop]

Sounds like the Valves are glowing. Take the head off before you spend anymore.

[noah123]

Thanks guys. Regards valves I'll ask, but I believe he said he adjusted them a couple days ago. I'll check coil, going back to the shop tomorrow.

[Ace of Pop]

Years ago I had a share in a Gas Conversion Co, before ECU s n Fancy Inj Systems, hence my interest here, sold my share after 2Years. Got pissed off with Complaints about misfires. Normally burnt Valve seats, overheating , and reluctance of folks doubling up on oil changes as required back then. Unless the engine is a Factory Gas id take the crap off.All the ferang folks I know here waste their money, their millage is too low to ever get the conversion costs back., plus I hear the Nohas tale far to much even with todays developments. The Honda City Gas seems to be O.K though.

[ktm jeff]

Have you checked for inlet leaks (at manifold / sensor / valve gaskets) as excess air causes surging. Could happen more when engine gets warm and expands , causing a gasket to leak.With engine running , hot and cold , spray carb clean around all inlet joints / components.Carefull !.

[noah123]

Today, first day after ECU/computer replaced, the car ran decently all day. Yesterday the light came on once, today not at all. However, when stopped or put in Park, on occasion the Tachometer had a slight up and down fluctuation.

I will check Friday as you said ktm jeff.

And thank you again everyone for the suggestions.

[noah123]

Well, we switched out the new computer to our old one. The mechanic said we need a new IACV. And now the power steering rack has gone out. Yay I love cars lol.

So we are looking for a 2nd hand IACV and steering rack.

[WarpSpeed]

Air in the coolant system can cause idling problems as several sensors for the fuel control that attach to the intake are cooled through the cars water system and so can the idle control solenoid just behind the intake manifold, tap on it with the heavy end of a screw driver while the car is running, if it causes any fluctuation in idle speed it is faulty. The change in computer sounds good, hope it actually does solve the problem, but sometimes just the change is a reboot and works temporarily until the fault shows up again, if it does? Try the things I suggested to confirm or eliminate as issues.

[noah123]

We changed back to our old computer. I believe its as you said, the reboot created a temporary fix. We drove 20min, after shopping then starting the car back up same issues as with old computer. Then, it didn't act up again for 3days. When we took it back to the mechanic it didn't act up again...until he was just about to hand the car back over to us and it acted up every time he turned it off and on. After putting back in our old computer, it acted up also, behaving the same way. We drove 5min to put in more LPG. After filling up, turned the car back on and not a single problem for the rest of the drive (40min).

I will give the IACV a tap like you suggest.

Please forgive my ignorance, but how do I check for air or remove air from the cooling system?

[lust]

to remove air from the coolant you can start the car with the radiator cap off and let it reach normal operating temperature. if there is air you will see airbubbles coming up and it will bubble a bit and you might need to to top it up. dont worry its safe, wont spray everywhere

[noah123]

Thanks mate

[transam]

to remove air from the coolant you can start the car with the radiator cap off and let it reach normal operating temperature. if there is air you will see airbubbles coming up and it will bubble a bit and you might need to to top it up. dont worry its safe, wont spray everywhere

It might...................

[noah123]

Lol