volvo 760 2.8 gle engine problems

[gordyctill]

hi I have a 2.8 v6 it is a 1988 I am having engine issues idle is low and lumpy won't rev and when I get it to rev it backfires I have run out of ideas please help

[Laird Scooby]

Originally Posted by gordyctill

hi I have a 2.8 v6 it is a 1988 I am having engine issues idle is low and lumpy won't rev and when I get it to rev it backfires I have run out of ideas please help

Many things to check! First, is it a B280E or a B280F? Second, have you done anything to the engine/underbonnet area recently? Have you checked the intake trunking between the MAF and throttle body?
Have you cleaned the PCV system including the oil filler cap? Any air leaks on those? Are the "O" rings intact and in good condition on the oil filler cap and dipstick? Do the check valves on the pipework for the Climate Control all work as they should? Is the brake servo working as it should? Is the throttle butterfly adjusted correctly and never been touched? Is the TPS correctly adjusted?


I could go on but that lot will keep you busy and give a few clues!

[gordyctill]

hi I have checked the following new idle valve checked all pipes new radio relay new coil new mass air flow 2 years ago new knock sensors checked the in tank pump and is working and relay is working I am at a loss

[Laird Scooby]

Originally Posted by gordyctill

hi I have checked the following new idle valve checked all pipes new radio relay new coil new mass air flow 2 years ago new knock sensors checked the in tank pump and is working and relay is working I am at a loss

What make is the MAF and was it genuinely new or just new to the car?

Also is it a B280E or a B280F? Second, have you done anything to the engine/underbonnet area recently? Have you checked the intake trunking between the MAF and throttle body?

[gordyctill]

my engine is b280f. the mass air flow sensor I got new and I have checked the trunking and its fine I think something has failed but I don't know what

[Laird Scooby]

Originally Posted by gordyctill

my engine is b280f. the mass air flow sensor I got new and I have checked the trunking and its fine I think something has failed but I don't know what

Originally Posted by Laird Scooby

What make is the MAF?

Also how did you check the trunking?

[gordyctill]

I checked the maf and the trunking by putting my hand over the end and the engine stopped mite not be the right way but it stopped the engine

[gordyctill]

I forgot to mention I have cleared the throttle body and the tps is working

[Laird Scooby]

Originally Posted by gordyctill

I checked the maf and the trunking by putting my hand over the end and the engine stopped mite not be the right way but it stopped the engine

WHAT MAKE IS THE MAF?????

Have you still got the original?

That won't give a conclusive result, testing it that way. You need to remove it and examine it closely, particularly around the points where the stubs join it for the AICV and breather hoses.



That's 50mm wide self-adhesive aluminium tape wrapped and overlapped to cure a similar problem on mine. I couldn't find any holes, cracks or otherwise but it cured it. A side benefit was it keeps the incoming air cooler so it's more dense - better power and economy.

You could also have a blocked cat, i don't have a cat on mine thankfully (B280E) and you can legally decat yours as the 760 wasn't made long enough to mandatorily have a cat.

It could also be the ECUs CTS, located on the 'stat housing but that usually shows as a rough idle and high fuel consumption.

Another thing it could be is the Fuel Pressure Regulator (FPR), that can do similar.

Everything so far is pointing to the MAF having failed, if it was a Bosch unit then it shouldn't have failed so quickly but if it's a cheap Chinese one, it could well have done.

I'm asking a lot of questions because they need to be asked so please don't ignore them, it will make the process slower than it needs to be and in my case painfully slow because i'll have to keep repeating questions and my hands don't like typing!

When were the plugs last changed, also dizzy cap, HT leads?

[gordyctill]

I have changed the spark plugs the the maf is a lucas make I have look at bosch but dam expensive