Miss/ hesatation problem please help !

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bman68, Oct 8, 8:51pm
I have a 96 ford laser with a 1.6 dohc fuel ejected motor it idles good and runs alright until about 3500rmp it kind of cuts out and there's no power and the rpm drops any help cheers

franc123, Oct 8, 9:12pm
Buggered HT leads or oil leaking into the plug wells was the usual cause of misfiring in those but in your case I'd be checking and changing the fuel filter first and making sure the fuel pressure and flow is to spec, if the filter is blocked the pump is likely well on the way to being nuked. Filters were on a 80k replacement interval for that model but rarely ever get done.

bman68, Oct 8, 9:19pm
thanks I am going to check this out ill let you know how I get on :)

m16d, Oct 8, 9:31pm
Air filter.

gazzat22, Oct 8, 9:42pm
Got a Rev Limiter on it? What gear is it in when it cuts out?

intrade, Oct 8, 10:11pm
yes first thing i was thinking was mechanical rev limmiter gone week spring
so find out what rpm limmiter they use a old golf vw use exactly such spring centrifugal divise
when warm rev it in idle to 4800rpm to see idle fuel consumption is low
but rpm limmiter woul kill it at your 3500 to 3800 each time it cuts ignition di-di di di sound if you ever heard it vw limittrer of gti 1.golf is 7000rpm or so
this test goes with pos t #2 post the results

mm12345, Oct 8, 10:40pm
I agree on the HT leads there for those engines. Not sure of reason (something to do with wasted spark system?) , but when the leads were rooted, they'd have symptom that felt like hitting a fuel starvation brick wall under load at about that RPM, yet seemed to run fine at lower load/rpm.
Even if the stalks are clean, it's very hard to see where they've been arcing through.

bman68, Oct 8, 11:27pm
just been for a drive up and down the road. the first time it reved to 4000rpm in first and didn't stop I went to second and it died at 2000rpm and the died in third also. if your very light on the gas it goes alright. I guess it doesn't just cut at 3500rpm its all over the show. you put your foot hard into it and there is nothing at all it like its lost fuel completely.

jmma, Oct 8, 11:41pm
So did you change the fuel filter? If not it will be a good place to start. (o:

intrade, Oct 8, 11:45pm
change your fuel filter soonest might be a bit tricky diy . you would need to mesure fuel pressures with a gauge , but if you change the fuel filter for a new one fitted correctly usually has large and small bungs and a arrow of flow direction.
that will eliminate the most probable cause of hesitation.
under load the engine injects more fuel and then it runs out of fuel and hisitates its what your test drive just confirmed to about 85%

franc123, Oct 8, 11:53pm
One other thing, check that the large rubber tube between the air filter and throttle body hasn't got any cracks in it, especially underneath.

intrade, Oct 9, 12:00am
if fuel filter did not fix it report back it will get more tricky for diy test with no tools but i have some tricks you can use before you need tools.

fordcrzy, Oct 9, 1:20am
these motors eat leads and plugs. change your leads with NGK leads only and NGK plugs.

bman68, Oct 9, 1:36am
its not always when under load its sometimes when in first and when just reving the engine .

bman68, Oct 9, 1:47am
do you have any idea what the resistance values of the leads should be ?

franc123, Oct 9, 2:23am
Now you've revealed that, REMOVE AND CHECK THE INTAKE TUBE. If there's a split in between the convoluted areas that's opening up when the engine tilts slightly when accelerating the air flow meter readings go haywire and thus fuel injection quantity does too. If it is cracked, tape it up and refit it until you can get another one. Very common on injected Lasers and similar Mazdas.

bman68, Oct 9, 2:53am
I've give it a good inspection and there are no cracks but there was a few age cracks but nothing that went all the way through taped it up any way but its made no difference. it drove fine when I drove it home the other night 100km ish but since pulling the gearbox out its started doing this.

tamarillo, Oct 9, 3:25am
So only did it since gearbox out. Ok so what else needed removing doing that? Gotta be connected surely?

fordcrzy, Oct 9, 3:41am
just replace them. no point measuring them it means nothing. if it started doing it since a gearbox pull id check your earths first. make sure your airflow meter plug is in properly as for plugs and leads. haveing owned a b6 motor for 16 years i can say replace you plugs and leads with quality NGK ones or youll be back with the same issues within 24 months.

bman68, Oct 9, 4:16am
I have replaced ht leads but it makes no difference :( cheers for the help guys but no luck.

andy61, Oct 9, 4:35am
It was common for Lasers and 323 to do the ignition module.

mm12345, Oct 9, 4:53am
Yep. I give up with any suggestions since OP waits until #17 to announce that "minor detail". Not just what else needed removing, but what else was done?

bman68, Oct 10, 3:42am
put a fuel pressure gauge on it today and drive it around the block when it lacked power the pressure was low. turns out the fuel pump pick up was damaged and was sucking up air with the petrol creating a low pressure all sorted now runs sweet as thanks for the help guys .

jason_247, Oct 10, 3:48am
your first though on a fuel injected engine was a centrifugal rev limiter?

jason_247, Oct 10, 3:49am
nice result, ive seen similar on a car that would miss badly under half a tank of fuel. same issue, crack in the pump pickup