16 replies to this topic

[Jackman]

Right im having a few problems with my SPI.

Engine Spec

1293 stage 3 with a Kent 274sp cam. LCB, single box rc40 and a k&n57i air filter.

Problems (All intermitant)
Occasional misfire, as in one miss and then carries on. Normally when cruising, never under load.
Hesatation, put my foot down to get out of a junction in example and it just bogs down but clears then runs fine again, also does this at times when accelrating hard.
Idle, its always had a lumpy idle due to the cam but recently its felt "rough" the engine vibrates and can feel it in the car, it also gets confused at times and idles just under 2k.

Took the plugs out and had 3 rich and one lean, number 4 was lean 1-3 rich. However this doesnt help much as i had a water temp sensor fault and it underread, that is now fixed so will re-check the plugs in a few days after normal driving conditions (only done small trips at the mo)

I have had the fault code reader on the ecu and it reads no faults, the temp sensors are reading correctly too.

I have checked all the connections, the gap between crank sensor and trigger wheel (its an external crank sensor as im not using a spi transfer case) and the dizzy is in good working order.

Any other places you can think of checking?

[SMP]

The evidence always points to the answer and should never be ignored. How many times after you find the cause of a problem do you find that all of the pieces to the jigsaw were there in first place - sometimes we just stubbornly try to make them fit a different puzzle!!

That plug is telling you something.

Have you set the valve clearances properly. Are the plugs all the same grade? Try moving the plug to a different cylinder.

Try a compression test. Have you got a colour tune - or better still two ( to compare between cylinders).

Has it ever run properly - has it been across a rolling road.

Just some thoughts

Steve

[Roo]

Head gasket?

Mine would act like it was miss firing when mine went... didn't want to go when moving off out of junctions etc. had to go down a gear and rev it a bit to get it going when driving normally.. on one occasion i had to stop, turn the engine off..wait 10 mins, restart it to get it to behave normally.

Worth a check?

Edited by Roo, 04 January 2009 - 08:06 PM.

[Jackman]

The plug cant tell me anything for two reasons.

1) The temp sensor was underreading making the ecu think it was colder than it was and overfueling
2) The locating ring was stuck in the inlet port (sideways) not sure if that would have caused anything or if id done that removing it.

I need to drive the car normally (ie to and from work) for a few days to then re-check the plugs.

Not had a compression test done recently somthing i shall check and its never needed to be put on the roller but it has ran properly before.

Forgot to mention in the first posts its got a 1.4 metro injector as when it last went on the rollers it was very lean top end, this injector fixed that. Its also running on once in a blue moon after turning the engine off... how this is possible i dont know.

If it was headgasket id expect it to do it constantly or use oil and water. However it doesnt.

Edited by Jackman, 04 January 2009 - 08:08 PM.

[Roo]

The plug cant tell me anything for two reasons.

1) The temp sensor was underreading making the ecu think it was colder than it was and overfueling
2) The locating ring was stuck in the inlet port (sideways) not sure if that would have caused anything or if id done that removing it.

I need to drive the car normally (ie to and from work) for a few days to then re-check the plugs.

Not had a compression test done recently somthing i shall check and its never needed to be put on the roller but it has ran properly before.

Forgot to mention in the first posts its got a 1.4 metro injector as when it last went on the rollers it was very lean top end, this injector fixed that. Its also running on once in a blue moon after turning the engine off... how this is possible i dont know.

If it was headgasket id expect it to do it constantly or use oil and water. However it doesnt.

Mine didn't... I didn't know it was head gasket until it blew on the A404 causing the first crash... Before it i had allsorts of issues.. and it would 'miss fire' at all the wrong places like at roundabouts.. when i wanted to pull out i could only go at 10 MPH cause it was having issues. Had no evidence of it being the head gasket with regards to oil and water loss.

[SMP]

We'll have to wait and see about that plug!! Why should only three of the plugs be affected by the temp sensor

Good luck.

Steve

[Jackman]

I dont know, its why im thinking the locating ring caused flow problems if that was the case. Aim is to check the plugs one night next week and see if they are the same, if so check the tappets.

Also best not be the head gasket, only did it in august when the new head was fitted.

[Sprocket]

I'll speak to you later about this but have you fitted a genuine SPi manifold gasket like I suggested

A single plug showing lean is a little worrying.

Compression test?

We really need to check the ignition advance is matching that of the diagnostic, to make sure the trigger is in the right palce, couil be out by 5 degrees perhaps, even though I did set it up with the DTI

Alternatively you could swap out the whole lot with the gear I have on the shelf not doing anything at the moment to see if this ghost disapears :S

[Jackman]

Tomorrow night im going to pull the plugs again and see what they are like then. Check the gaps again too make sure they are right.

I cant see it being the ignition advance as when the engine went in it was sweet as a nut so unless the wheel has moved somehow i doubt its that.

Ill speak to you about it tomorrow mate, but what gear do you have laying around?

Edit

Also ive not changed the gasket yet. Its too cold and such a pain.

Edited by Jackman, 04 January 2009 - 11:06 PM.

[Sprocket]

what gear do you have laying around?

Erm well You know I originaly ran the 1400SPi and you also know that I'm now running the 1275 16v. So, pretty much everything

[Jackman]

Update

Plugs 1-4 bob on. Perfect colour and gapped correctly. As for why one ran lean i dont know but i shall keep my eye on that.

Possibly fixed the idle at the same time. One of the breather pipes was not fully attached so must have knocked it when i did the temp sensor, idle seemed better on drive, will find out on the run to work tomorrow morn.

As for compression... i dont know... gauge is bust

Also Sprox... o yeah

[Sprocket]

Coolio and no worries

[Jackman]

Right Update time.

New plugs in (Cracked ceramic on one plug)
Re done coil connections.
Just above 16bar of compression on all cylinders, all near enough equal.

Random misfire seems to have gone. Was perfect on the run yesterday.

Problem left, according to my mate behind me at low revs it runs rich and it still hesitates at low revs when trying to have a spirited getaway, the hesatation is half bogging down and then it has a misfire so its obviously going rich when trying it.

[Sprocket]

you might be at the limits of that ecu. Do you want to try the Metro GTa one I have. Only a loaner mind

[Jackman]

you might be at the limits of that ecu. Do you want to try the Metro GTa one I have. Only a loaner mind

I thought that. Everything seems right, just think its confused with what to do.

I think that maybe an option for now, see what happens. Thinking more along the lines of changing to Vems if i cant get it sorted.

What compression did you 1400 have?