What is you opinion on this?

[ALS]

I have this reoccurring miss that is driving me nuts. Only does it on the highway after 5 or 6 hours. It comes and goes and I have replaced every possible electrical part, including relays,O2 sensor and the FPR and it still does it.
Now here's where I'm at, I went for my state inspection and had a very hard time getting the car through emissions. At idle my CO was off the chart and once the RPM's went above 1500 it settled right in where it should be. We played with the AMM (Air Mass Meter) and that wasn't the problem. From a Canadian Emission site I found high CO was caused by excessive fuel. I figure I'm looking at a leaking injector(314K miles)as the problem. Now the $64K question if that leaking injector was going bad would it be possible that it is causing this Miss once it is nice and hot and running for a few hours? Fuel mileage is fine at 20 around town and high 20's to 30 mpg highway. 1987 745 Turbo M46 and 314K miles on the injectors, 30K on the long block.

 

[Gary Allan]

I imagine that the leaking injector is your high CO problem ..but I can't figure it as the cause of your miss.

We had this in a Ford product (TBI) that we owned. No codes ..just no rhyme or reason to the occasional "buck" that would occure from time to time. We finally gave it to a trusted mechanic that had a Sun Interrogator and after running the battery of tests, did the "wiggle" test. He found the faulty connector that would break contact for no good darn reason from time to time.

Many scanners can perform the wiggle test. It merely polls all the sensors and you wiggle all the connections ..when it reads a loss of V ..it beeps (this is the effect anyway).

 

[TheLoneRanger]

quote:

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Now the $64K question if that leaking injector was going bad would it be possible that it is causing this Miss once it is nice and hot and running for a few hours?

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Yes, it very well could. If the injector is sticking open at idle, it could also be sticking closed when hot.
314K is a lot of miles on injectors, so you might as well change all of them. It'll be hard to find the lazy one, since the miss is so erratic.

Maybe you could listen to them at idle, and find the leaky one. (A piece of garden hose will work if you don't have a stethescope). Even so, it may be a different one that sticks closed when it's hot.......?

 

[ALS]

Ordered 4 new injectors today from my local foreign parts store. I almost hit the floor when he said they were expensive at $85 each with new seals.
I couldn't find them on line cheaper than $92 plus shipping.

I saw them as high as $140 and never went near the dealer parts counter.

 

[brianl703]

http://www.lindertech.com might have 'em cheaper, but those are rebuilt/reconditioned injectors, not new ones. On the other hand, they are flow-balanced.

From what I've been able to determine, most top-feed injectors are the same physical size with the same electrical connector, the only real differences are the flow rate (lb/hrs) and whether they are high impedance or low impedance injectors.

Side feed injectors are different, but few vehicles other than some Nissans and Fords used those as of the late 90s.