missing/hesitating under acceleration issue

hejira · Postby **hejira** » Thu Jun 03, 2010 7:19 pm

Hi all, tried a search but couldn't quite find anything similar.

Background is I have a '90 with a 1.8 engine (engine has done 50k & the rest of the car has done 200k), last time a service was done I wasnt the owner, & the fuel filter wasnt changed. The previous owner also supplied an aftermarket clutch kit he was planning on installing soon. I always feed it 95 or 98 fuel.

A week ago the car occasionally started missing under acceleration between 2000rpm & 3000rpm, it would hesitate badly & sounded like its running on 3 cylinders or like a boxer engine.
Since then, it has progressively become worse to the point where most of the time whenever im not extra gentle & slow with opening the throttle to accelerate, the same thing happens, between 1500rpm & 3000rpm, plus it now misses a fair bit any time in gear at any RPM, but it always idles perfectly.
I tried opening the throttle from the cable in the engine bay & the RPM rises as it should.

Anyone had the same before? Anyone know what is most likely the cause?

Thanks for the help!

StanTheMan · Postby **StanTheMan** » Thu Jun 03, 2010 7:49 pm

I'd start with some new leads.

silvermiata · Postby **silvermiata** » Fri Jun 04, 2010 3:23 pm

i had the exact symptoms, and it was the fuel pump...

DaveWA · Postby **DaveWA** » Fri Jun 04, 2010 5:00 pm

i put my money on the Fuel filter......

Guran · Postby **Guran** » Fri Jun 04, 2010 5:03 pm

+1 on the plug leads

viewtopic.php?f=18&t=39032

GP14 · Postby **GP14** » Fri Jun 04, 2010 6:08 pm

+2 on the leads

hejira · Postby **hejira** » Fri Jun 04, 2010 6:36 pm

any more votes on leads or fuel filter? I'll try what ever gets the most votes first.

RawSouth · Postby **RawSouth** » Fri Jun 04, 2010 6:38 pm

hejira wrote:any more votes on leads or fuel filter? I'll try what ever gets the most votes first.

Why not do which ever is cheapest first? or talk to one of the forum sponsors? They would have some leads you could probably borrow to eliminate that option...

hejira · Postby **hejira** » Fri Jun 04, 2010 6:47 pm

Yeah i probably will do whatever's cheapest first, tomorrow is the next chance ill have to look at it again..

Guran · Postby **Guran** » Fri Jun 04, 2010 7:10 pm

Of you've got a multimeter you can do the tests I described in the above linked thread. If the plug lead resistance is out of spec then you're pretty safe spending the $80 for plug leads knowing that it should solve the problem.

hejira · Postby **hejira** » Fri Jun 04, 2010 7:32 pm

I probably should buy a multimeter anyway, good advice there, cheers.

Guran · Postby **Guran** » Fri Jun 04, 2010 8:11 pm

If you're going to buy a multimeter, make sure you get one that is calibrated to measure engine rpm too. It's essential for setting your idle speed accurately.

93_Clubman · Postby **93_Clubman** » Sat Jun 05, 2010 7:02 pm

hejira wrote:it has progressively become worse to the point where most of the time whenever im not extra gentle & slow with opening the throttle to accelerate, the same thing happens, between 1500rpm & 3000rpm, plus it now misses a fair bit any time in gear at any RPM, but it always idles perfectly. I tried opening the throttle from the cable in the engine bay & the RPM rises as it should.

So it's breaking down under load, but not when stationary - plug leads again.

hejira · Postby **hejira** » Sun Jun 06, 2010 1:41 am

I havent changed the leads yet cause no where I rang in brisbane today had any in stock except repco who want $150. pulled each lead plug out & found one of them was slightly dirty/oily towards the bottom. then took it out for a spin & found that it barely does it when its cold, just a slight flutter with heavy throttle below 2000rpm sometimes in the first 5mins, but the longer the car has been running for the worse it gets, after driving round for 15mins it started missing & hesitating almost every time I accelerated. will find cheaper leads this week & post results.

Yeebus · Postby **Yeebus** » Sun Jun 06, 2010 4:16 am

I had this problem just a while ago. Turned out it was the leads.

The mechanic I took it to just taped them up as a temporary fix while I buy new ones (I assume the tape is around the rubber part that is closest to the spark plugs). Not sure what tape to use if you want to try that though.