s2 2,9 lumpy running

[oldtrev]

here we go again ive a 1989 s2 2.9 starts and ticks over fine through the gear box goes like a bullet,but between 1000rpm & 2000rpm like driving a pogo stick very lumpy when trying to cruise
ive changed the plugs ,dizzy cap,leads,ignition coil still no joy whats the cure?help please

oldtrev

[phillpot]

From your description would think ignition problem (all the bits you've changed) unlikely, that wouldn't cure itself over 2000 revs ?

My guess is fuel ratio and or air leak, and while I'm all for doing my own maintainance whenever possible unless you do know what you're doing (and I have no idea of your skills, experience or knowledge) its possible to spend a small fortune on the "I'll try changing that bit next" scenario ?

Might be worth asking on here for recommended garages in your area, not nesseccarily TVR, but somewhere with a mechanic old enough to have worked on Granadas and Sierras, where these engines came from ?

Hope you get it sorted soon, if you think the cars fun now just wait till its running right

[tozerman]

Welcome to the forum, open this link about 2.9 ford diagnostics it helped me hugely when I had the same problem, setting the throttle stop screw was the single biggest improvement I have done to my car

http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

Good luck with it.
Cheers.....Tony..

[ketvrin]

At those revs I would go for the ISCV and the TP as the main culprits...

K

[tvrgit]

Had to check that link above because I've been moving stuff about my webspace, but it still works!

I suspect Kevin is right - I would go for the ISCV personally, before the throttle pot, but it could be either. Could be an air leak on the inlet side, but I think the symptoms of that would be slightly different.

[ketvrin]

Another useful link (that you can find in the "Useful Links" wiki) is this one...

http://www.fordscorpio.co.uk/faultfinds.htm

K

[tvrgit]

Good reminder there Kevin.

I see on that page, it refers to "engine loom" (although it says for the DOHC 2.0L engine) but that reminds me - there is a loom connector that sits on top of the RH rocker cover (under the coil) and that carries all the signals (ISCV, TP, coolant temp, etc) back to the ECU, and it's prone to corrosion. Because those signals are low voltage and very sensitive, dirty connections can really screw up what the ECU thinks it's doing (and what it tells the engine to do).

It's maybe worth pulling that connector apart and cleaning the terminals with electrical contact cleaner, and see how that goes - it can make a difference.

[jimed]

Hi oldtrev - as I said on your other post these guys on here are the mustard - really helpful. Good luck.
Jim

[ketvrin]

And welcome to the forum... dont forget to add your details to the Owners List (or let me have them and I'll do it for you.

Jim is looking for a way back I reckon, along with Graham and Tom and Dale

K

[jimed]

I don't think I'd go back Kevin - the Griff is rather nice but I did love having the S which was easy to live with and great fun.
Jim

[Spathodus77]

I had a similar problem and it turned out to be the electrical connections on the air flow meters, bit of emery paper to clean them up and some wd40 sorted the issue. Its a cheap fix and these connectors are easily accessible. Because they are close to the wheel they do tend to get hit by water/salt etc...

Ralph