v6mike

i have a 1993 3rd gen twin turbo, every now & then there is hesitation & lacking from the engine, it is inconsistant, my boost guage & automixture guage are saying nothing is wrong, can anybody help me please im running out of ideas

by the way i have changed the fuel filter, spark plugs, air filters & checked all the vaccum hoses

FDAsh

Do you have open filters? Could be hot air being sucked into the turbos.

When does it happen usually - is it from being at a standstill to getting moving again?

1QWIK7

iTrader: (33)

Check TPS measurements.

How about your grounds? Did you check those?

Ernesto13B

iTrader: (4)

sounds like the good old "3000 RPM hesitation." Try using the "search" to find out more info about it, and Look on FD3S.net. I had this problem, and for me it was a missing engine ground. As soon I installed the missing ground, the hesitation was gone.

v6mike

thankyou for getting back to me

it happens from cruising to putting your foot down, stutters around 2500-4000 put seems to lack power in general when she is running well
(my automixture guage & boost guage reads all ok)

i will check all my grounds in the mean time, im also putting new ht leads on 2day

would you know what the tps gap should be??

yes i do have open filters, recently replaced but it was fine with open filters before

--- it has also starting running inconsistant on tick over too, & takes a few secs to settle herself, could this be part of the same problem?

your help is much appreciated

dgeesaman

iTrader: (7)

The 3k hesitation pretty much happens at 3k only and around 0psi of boost. More boost or any other RPM and it's something else.

If you see boost on the gauge and you're not getting the power consistently, then you should check into fuel and ignition. Put in new plugs first off, use the 9s and 7s like the manual recommends.

What boost are you seeing when you aren't getting good power?

Dave

v6mike

im still getting top boost of 8psi wether its lacking power or not
so i know the turbos & intercooler are operating fine

dgeesaman

iTrader: (7)

I forgot to mention you should pull the ECU codes, if any.

I would put in the new plugs because plugs don't last long in FDs and this is a new car to you. There are numerous other maintenance items I would do as well but they aren't relevant to your problem at the moment.

If the plugs don't solve it (and they probably won't), I would check fuel pressure per the FSM. Then, I hate to say it, check the injectors.

v6mike

i have fitted new plugs & leads, & just been out on a test, seemed to be running fine for a good 30min, gave her a good thrashing in that time & all seemed good, until i came into the town,cruising at 30-40 mph in 4th gear & the running of the engine slowly got worse & worse of hesitation at low revs, & a very unhappy idle

i gave her a small blip on the throttle at stand still & the idle drops dramaticaly to about 500rpm, then slowly levels herself back to normal

any suggestions?

your help is much appreciated

(i have done all the matenance needed - oil & filter, coolant change, trans oil change, new belts, air filters, fuel filter, plugs & leads

chuckdog_5

is there a shop around you could take it to? not a normal one, a rx7 shop

dgeesaman

iTrader: (7)

You just bought the car, so I'd change the fuel filter and do a fuel pressure test next. The fuel filter needs to be changed on this car more regularly than most cars. It's also a minor pain in the butt, which can lead to it being skipped from the routine maintenance and further problems.

Dave

Blaen99

iTrader: (1)

How often is 'more regularly', out of curiousity?

dgeesaman

iTrader: (7)

Whoops, you said you already changed it. I would go straight to a fuel pressure test.

IMHO, 15k or 30k for the fuel filter. Clogged filters cause major trouble on these cars and for the small added cost I think it's best to err on the very conservative side. You definitely aren't doing yourself a favor by waiting a full 60k.

Dave

v6mike

thankyou all very much for your help

i changed the TPS sensor
added a couple of more grounds
& reset the ECU

problem solved

Big Hugh Ness

Whoa! Have you seen where that rotten fuel filter is located? Man, I'd be changing it once every hundred years at most, and thank God I am not a turtle because I wont live that long, which means, I will only have to do it once. Fact is, I haven't done it yet. The (friendly local) mechanic who freely admitted his lack of experience in these things told me the filter was a completely different thing to the oem unit I had, so he blankly refused to install it. I reckon he might be pulling a fast one just to avoid the job. Such is the fear and trepidation changing a fuel filter causes. I actually have no excuses and your post has made me think about getting under there and doing the damned job.
Good luck.

v6mike

its not too difficult, when you know how...
the trick is to have the car as high as possible, (preferbly on a 4post ramp) i did mine laying on my back with the car on axle stands
each side of the diff there is a plastic guard & a metal guard -- remove them both.. this makes it alot easier for getting both hands up & around the diff,
the main thing is .... patience
mine took about 2 hours by learning the hard way, and i would change it every 10,000 miles
GOOD LUCK

94fdrx7

as **** poor as fuel quality is these days, i'd recommend replacing it every 10-15k miles...

Big Hugh Ness

Mmm. I knew you were gonna say something like that.