VanhireBoys

Hi Guys

Hows it going...? My '87 944 Turbo is misbehaving very badly at the minute !.

I was diving to my homeplace in Donegal - 150miles away when after 100 miles or so the car just didnt feel right. I was just tipping along at 60 mph or so no problem. I put the shoe down and the car started to hesitate, pop and bang and generally be bold. If you just tip around gently then no problem but once you try and gather a bit of pace or face a hill the misbehaviour starts

I shut down the engine and restarted on the run but no difference. I had myself conviinced that the fuel pump was the culprit - Checked fuel pressure 2.5bar at idle and a rise of 0.3 under load

Checked all the plumbing for the turbo and induction .. No leaks

Checked the recirc valve - no problem

Checked the security of the reference sensor and crank sensor - No problem
Apparently a duff crank sensor manifests itself as bad above a certain rev regardless of load

The throttle position sensor I am going to check tommoro when I get some leads from work

Ive gone off the fuelling as its showing 1.6% co at idle and 3.15% at a decent rev !

I am convinced now its electrical. Its as if the sparks are being fired in all directions ... I took off the dizzy cap - No dampness or cracks. The rotor I checked but seems fine.

Ive ordered up a new dizzy cap, rotor and coil ... just for piece of mind

Sorry for the length of the post lads ... I am looking for suggestions of where to go next with this. No suggestion will be disregarded .. I am willing to try anything to get the old girl back to health once again

blown 944

Have you changed the spark plugs and what is the gap? That is a very common issue if the plugs are old and are gapped to wide. I reccomend .025 gsp

mudbuddha

Also check for grounds...any water leaks onto electrical wirings?

XR4Tim

Check your spark plug wires. If there are cracks or even pin holes in the shielding, they will arc out under a load, and you will lose your spark.

JohnKoaWood

With the car running at idle in the dark look for sparks around the plug wires...

Tom M'Guinn

I'd just buy new plug wires for peace of mind, unless yours are virtually new. The problem you describe is consistent with a classic weak ignition, and the wires are a surprisingly frequent cause. No guarantees that's it based on reading your post, but odds point to the ignition.

dillon410021

the 4 strokes of an internal combustion motor are suck, squeeze, bang, and blow!

VanhireBoys

Thanks for the tips lads...! Very much appreciated

I repalced the plugwires in Sept. 2011 and I had a good look around the earths and plugs and stuff.. Nothing untword found.

I replaced the plugs last night and ran the car in the dark.. again no difference !
Wife thought I was crackers as the lights in the garage were off and the car was running....

I am waiting on a rotor and dizzy cap now as the next step. I am also going to check the throttle position sensor.. just to rule it out

I happened to talk with an elderly neighbour and he said the coil may be breaking down so for the piece of mind I have ordered one of them as well !

I'll keep you all informed as to how it all goes once the parts come...!

Thanks again chaps !

Bri Bro

I had a cracked cap and another time a bad speed sensor (melted the wire) that caused those problems.