Issue with accelerating past 40 mph...hiccups NEED HELP!

shebuilt · Post by **shebuilt** » Sat Jul 19, 2014 1:51 pm

Hard to explain as you can see by the title.

Baron has been running tip top. Went out last night on surface street and had a couple of hiccups while accelerating around 40. This AM on freeway we were cruising along at 80 or so and it was as if it lost power via acceleration? If I pushed him, he would basically catch up and keep going. No idle issue, no trans issues.

I am guessing fuel or?

I hope someone has had a similar issue and can help.

Sorry I can't describe in more detail. If we had a speed sensor I would guess this?

GripGreg · Post by **GripGreg** » Sat Jul 19, 2014 3:39 pm

Fuel pump or filter??

shebuilt · Post by **shebuilt** » Sun Jul 20, 2014 9:20 am

Hey Greg. No I can't really think these are fuel filter or pump symptoms. Seems to only happen on aggressive driving.

shebuilt · Post by **shebuilt** » Sun Jul 20, 2014 10:16 am

For those who may think fuel pump...would it be inline or main? What are symptoms on the one in fuel tank?

appreciate it.

Sev · Post by **Sev** » Sun Jul 20, 2014 6:09 pm

If the pumps, then its definitely not the one in the gas tank, my car turned off usually when i ran low on gas, even if i have gas in the tank. That was the cause, yours isn't that one. Maybe the the fuel pump (outside), if you haven't changed that, then wouldn't hurt if your keeping the car. Some relays, fuses. check those.

jkycia · Post by **jkycia** » Sun Jul 20, 2014 6:56 pm

I had a problem with an 1984 RX7 that sounds similar to what you are seeing.
It would start gagging when I was trying to push it at highway speeds.
In my case, it was the fuel pump. Maybe you should first change the fuel filter if you have not done that in a long time.

shebuilt · Post by **shebuilt** » Sun Jul 20, 2014 8:57 pm

New fuel pump (well within the last 6 months)...Can't hurt other than the price. I'll try that.

any other ideas, keep them coming! Thanks.

I knew I should not have cheated that one time and put ARCO gas!

GripGreg · Post by **GripGreg** » Sun Jul 20, 2014 9:02 pm

I use nothing but Arco,,,, but,premium only!!
Talk to one of the guys delivering gas about the different quality of gas.

CBradio · Post by **CBradio** » Sun Jul 20, 2014 9:15 pm

I have a question:

If you are in park and rev the engine, are there any hiccups through the range?

bizz · Post by **bizz** » Sun Jul 20, 2014 10:01 pm

Sounds like clogged fuel filter or injectors - both symptoms of dirty fuel. Definitely replace the fuel filter and put some better fuel in before changing the pump.

shebuilt · Post by **shebuilt** » Mon Jul 21, 2014 9:20 am

If I am in park or neutral it revs very high with no hiccups. Stutter seems to happen when I try to push him to speed a tad faster than normal. Honestly I putter around the streets at 40 and let him increase without much on the pedal. No issues when driving this way. The minute I try to floor it - hiccups stutters almost oddly seems to cut off (still on) and I push it further down and he picks right back up and shoots out like a rocket.

I can change the filter again but can't imagine the two fill ups of Arco did that much. Stranger things have happened.

For those who have had issues with the in tank fuel pump, do you think I can rule this one out completely with my symptoms?

shebuilt · Post by **shebuilt** » Mon Jul 21, 2014 1:04 pm

Sorry I stand corrected. When I rev it in neutral / park it stutters as well.

CBradio · Post by **CBradio** » Mon Jul 21, 2014 3:54 pm

Mine seems to have the same issue exactly at 3000 rpm but only with vacuum advance connected.... When i disconnect the vacuum advance there is no stutter whatsoever.

This tells me either my vacuum advance is sticking or something (not really sure how this capsule gets serviced!) .... OR perhaps my overall timing is just too advanced but Im leaning towards the former.

I think, and maybe some more experienced e12ers can confirm or disconfirm, that you'd be safe disconnecting it and revving if your stutter is under 4000 rpm, but take what I am saying with a grain of salt...

CBradio · Post by **CBradio** » Mon Jul 21, 2014 3:58 pm

Wait: also are you using the 530i distributor?
If so, you only have vacuum retard...

These distributors not only use vacuum retard/advance but also there is a centrifugal force advance inside the distributor. Could be your centrifugal advance sticking too. This gets serviced by making sure the felt pad under the rotor is oiled with some motor oil. If you suspect its really stuck, you can spray some PB Blaster under the felt first..

shebuilt · Post by **shebuilt** » Thu Jul 24, 2014 8:54 am

So can't be fuel pump (purchased unfortunately).

it won't rev past 2500 rpm without kicking down. I can rev higher past it but it chokes again. This happens in neutral or driving.

Anyone?

I have new distributor with electronic ignition installed about 6 months ago and it has been running great with no incident.

What could have happened? I took vacuum line off and it drops in idle so I believe this is working.