#5 cylinder

[rlibraman2k]

I recently had my injectors cleaned by removing them on my 94 Q because my car was "spitting" at high speeds every now & then--After the mechanic replaced the injectors and mounting the intake, my car would idle very poirly with a bad bad miss--I then replaced the injectors with some other injectors and the car ran the SAME way--I had a foreign car mechanic check it out and he said that all of my cylinders are running like new except #5 cylindr shows NO COMPRESSION--M y car was running fine before this whole procedure was started---The guy did remove #5 and #6 tubes to access the rear gas rail screw---Also, I noticed that after he did this, I could not find a couple of the plastic fuel rail washers --would it cause a problem if he dropped these washers in # 5 cylinder and why is this cyclinder showing NO Compression all of a sudden? Please Help--

[maxnix]

Gosh, who knows?

Washed by gasoline?

"#5 and #6 tubes"?

Sounds like someone who had no clue about the VH45DE.

[92Q45guy]

I would not take the mechanics word that # 5 has no compression. I would check it myself. Compression gauge is 20$ at autozone.

[92Q45guy]

Also, You said he had tubes 5 and 6 off. Maybe he reused the gasket resulting in a leak at the tube. That would result in poor compression. Maybe with the car running spray some carb cleaner at the #5 tube (If you can get to it. to see if there's any change in RPM.

[Q45tech]

Measure the #5 injector resistance at harness connector.

Technican or worse mechanic who don't work on Q engines daily are apt to make mistakes.

NO COMPRESSION ...............absolutely zero................is almost impossible.......if the piston is still in the bore.

Low compression is more common.............a true technican would record the levels in psi for presentation to you...............we normally just do one side to speed the process since a power balance tells us which side might be defective.

If a shop doesn't have a few old Q parts cars sitting out back you know they don't do much Q business and should not be allowed to touch the car except maybe an oil change under your supervision.

Much more damage is done by incompetant mechanics than owners [except incompetent owners who fiddle].

[ScottJackson]

Yup, ohm the injector first. If that checks good, go to the spark plug hole and check compression yourself. If it comes in really low, bring that cylinder to the compression stroke and hook an air compressor hose up to that compression tester hose to blow air into the cylinder. If you hear air coming out the intake, it's an intake valve. Out the exhaust is exhaust valve. Out the oil fill cap is piston/rings.

[carfrk666]

umm yes it would be a huge problem if he droped the washer or anything down the tube because it would bend the intake valuve or go into the piston and get knocked around (possibly damage piston) or come out and bend the exhaust valve, but small chance of this, most mechanics are better then that, all though i have seen it, i wouldnt worry about some plastic washers because as a mechanic myself i say that i loose lots of small little things like that when doing big projects, i usualy try to replace them all tho, but i would deffinatly go and check that gasket on the tube and the ones on the injectors first.