Topic: Desparate To avoid auto repair shop incompetence

[TwoTired]

So, I got a fuel pressure gauge.  It idles at 35 psi and goes to about 42 when you stomp the gas pedal.  Holds steady at about 41 psi with the engine off.  Pressure stays there with the engine off.  I checked 5 min. later and the press was the same.  Looks like book values to me.

So, I guess it's on to the cleaning the injectors... Monday or Tuesday.  Have to remove the plenum to get too it.  And, heal some from my last work encounter with it.  (Bruises come really easy while on Coumadin.  And, my creeper has NO padding.) 

Oww.

Just thought I'd add that the car seems to ignore both curses and cajoling.

Well the car needs paint.  Any suggestions for colors of Yellow?  It was a beautiful Metallic red when new.  But, of course, the paint was even crappier than the reliability of the car.

Wah

[scunny]

Just thought I'd add that the car seems to ignore both curses and cajoling.

haha
good luck there TT. I will stick to carbs and points thank you

[edbikerii]

Well, did you try cleaning the MAF?  It takes about 5 minutes, its basically free, and you don't need to crawl under the car. 

So, I got a fuel pressure gauge.  It idles at 35 psi and goes to about 42 when you stomp the gas pedal.  Holds steady at about 41 psi with the engine off.  Pressure stays there with the engine off.  I checked 5 min. later and the press was the same.  Looks like book values to me.

So, I guess it's on to the cleaning the injectors... Monday or Tuesday.  Have to remove the plenum to get too it.  And, heal some from my last work encounter with it.  (Bruises come really easy while on Coumadin.  And, my creeper has NO padding.) 

Oww.

Just thought I'd add that the car seems to ignore both curses and cajoling.

Well the car needs paint.  Any suggestions for colors of Yellow?  It was a beautiful Metallic red when new.  But, of course, the paint was even crappier than the reliability of the car.

Wah

[kghost]

NO YELLOW....bananas are yellow.

[tonycb650]

How about candy gold ?

[masonryman]

I bought a 90 firebird new and kept it for 14 years, before I got the bird we drove a 88 IROC with 10,000 miles on it and the 305 bird ran better even though it was not nearly as cool as the IROC.

It has always seemed to me that the TPI engines did not breath well enough to perform properly, not enough air in and to much back pressure on the way out.

I fitted the firebird with Summit SLP headers, exhaust and  cold air intake.

[TwoTired]

Well, I healed up enough to do more work on the POS. 
What a pain to get those injectors out.  You know they want you to drain the coolant for that.    It's far easier to get sardines out of can intact (perhaps even alive).  The car was clearly built sequentially.  And, everything that was put on after a part was installed during construction has to be removed to get at the part you need to get to.  There was NO plan for maintenance after being built.  I've no respect for GM designers anymore.

Anyway....

Pretty sure I found the culprit.  I did yank the injectors for cleaning and flow testing.  But, I noticed an electrical connector on them.  Noting that I have a pretty good DMM and I know how to use it, I decided to probe the little bastids. The injectors are supposed to have about 16 ohm coils.  I've got 6 that read that.  The other two (one on each fuel rail) are 7 and 8 ohms respectively.  That can't be good...

With some searching I found this is a common issue with the stock Multec injectors.  The consensus is that they are crap and need to be replaced en masse, preferably with Bosch units.   And, it seems to be worse for engines that aren't run very much. (not sure I understand why, on that.  But, mine certainly qualifies).  If you watch these videos, you can get a good idea why my POS is running so erratic.  Sure enough, when they get hot, even "good" ones get worse.

Local auto parts store wants $99 each for new ones, and $75 each for rebuilt.     Borg warner manufacturer/ re-builder.

I found Bosch injectors here:  http://fiveomotorsport.com/Injector_SetsTPI.asp#caddy
For $305 a set.  Looks attractive.  But, I'll have to call them Monday to find out if I need new connectors on my harness for them.

So, that's the progress so far...  I've no doubt that J-random auto shop would have fleeced me for thousands of bucks, and perhaps still not have fixed it.

Cheers,

[Jerry Rxman Griffin aka MuthaF'er]

Lloyd,

Glad you're feeling better. Very interesting videos. Too bad we have carbs.

[mrbreeze]

Glad you finally stumbled on to the problem Lloyd.People don't realize how complex cars are these days.Like you said...some shops would throw a mass air flow sensor on it because thats what the code said was out of spec. You have to find a reputable shop that employs techs that know what they are doing. If you would have had a scanner at your disposal,you would have been able to diagnose your problem just by watching the data stream.New cars (OBD 2) are even easier. You would have set misfire codes and been able to isolate the problem immediately.I remember an early 90's Olds I worked on years ago. I did an injector resistance test like you just did and found 2 out of 6 out of spec. After replacing the bad ones...the car ran good but went right back to running bad after an extended warm up.Went back to recheck all injectors again and they were fine.Check fuel pressure at cold,totally warmed up.....good all the way through. Finally put it on the scope when it acted up and found bad plug wires.They worked fine and had good lines on the scope.......until they got warmed up.My rule of thumb is 100K miles on plug wires and then they should be changed.
Oh...and I hear you about getting those injectors out. I did an intake on a 98 Lumina the other day.6.5 book hours......I used to do TB or carbed intakes on Chevys around 3 hours. This silly little 3.1......took me 7 hours.(This one was a coolant leak).

[techy5025]

I chased a "low EGR flow" light issue on my Lexus for two months. The system has the EGR valve, a modulator/controller, and a temperature sensor. I replaced all three starting with the least expensive....90 bucks. Still bad.

Now desperate, I removed the intake manifold....half the engine has to come off. Turns out the recirculated exhaust gas is discharged into the intake manifold through a tiny hole drilled in a tube that runs across the manifold. It was plugged with a small piece of carbon! Cleared it with cleaner and a toothpick. Had I known, I could have cleared it by blowing compressed air through the EGR inlet. Oh well, I have a few spare parts now. 

I think I'll stick to working on bikes....old ones!

Jim

[mrbreeze]

It ain't rocket science.......sometimes.......

[mattcb350f]

How goes the battle TT? did you get the injectors back in?.....

 Matt.

[TwoTired]

How goes the battle TT? did you get the injectors back in?.....

 Matt.

Yes, I put in Bosch III injectors.  $212 for a set of eight, including the gaskets for the intake plenum. (Much better deal than the $75 to $100 for each injector (x8 plus 8.25% tax) that the local parts house wanted.) The thing hasn't run this well in 10 years.  It's actually fun to drive again. Especially without the CHECK ENGINE light glaring at you at random times.   And, now I remember why I bought the car in the first place.  It's a kick in the butt to fling around, and pretty darned quick.  Oh, and it passed smog test yesterday, well within test margins.
Still pretty pissed at GM, though.  The stock multec injectors worked just well enough to sell the car, but have no hope of lasting as long as the rest of the engine.  The injector solenoid wire coils are bathed in fuel.  And, the internal wire insulation isn't fuel proof.  It's a designed in failure mechanism.  I think I might stick the removed Multecs in the oven and see if the "good" ones change their resistance with temperature as I'm told they can.

Now I have a new dilemma, though.  We were all set to sell off the car and replace it.  Now we're wondering if the grins would be as wide with a another car.
I wonder how much a new paint job would cost...

Here's a pic from when it still had most of it's paint.

Cheers,

[DarkRider]

Repaint and be happy now that you got it sorted out man.

[Sporkfly]

Bosch makes good stuff. I drive an Audi 5 cylinder and I can vouch for them, everything electronic on my car is Bosch, the plugs are Bosch, plug wires Bosch, oil and fuel filter are Bosch...

They should do you well and I'm glad to hear you have it running tip top again.

[mark]

Hoo-ray for new injectors!

Since nobody else mentioned it and I just thought of it.......

How about checking with GM to make sure that you have the latest version PROM in the ECM?

They did a lot of bug fixes over the years. Some were recall material, others just got put in when the right tech got complained at. Tell a different dealer your tales of 19 years of loyal misery and see what happens.....

 


Happy trails.

[TwoTired]

So, I used the car to get a routine blood test for me.  It's been running well.  Doing short errands.  So, typical of the car, just as you start to build a bit of confidence in it.  The Service Engine Soon (SES) light comes on at startup before the drive home.
It was still running well, so I stopped for some errands on the way home.  Since I now keep a wire jumper in the glove box (to tell the computer to flash the codes it is complaining about)  I plugged it in, and it flashes a code 36.  My Camaro Shop manual from GM doesn't list a code 36!
Upon restart, the SES goes out like nothing ever happened.

What the fudge is a code 36!  A plea for attention from a neurotic computer?  Do I start calling it Marvin?

The PROM is the same one it had when I bought the car.  It's had 5 or 6 computers (which is one more than the number of times I washed out the engine compartment).  But, the PROM was transferred each time.

More internet searching ahead for me.

[my78k]

Hey TT try this link....

http://gmtips.com/3rd-degree/dox/tips/ecm/codes/code-01.htm

Dennis

[USN20]

This may help ....

http://www.chevythunder.com/fuel%20injection%20troubleshooting%20pg%20a.htm#36

From: http://www.chevythunder.com

[TwoTired]

Well, duh.  If you look in the right place in the manual, you find the correct code.  Turns out I was looking at the carburetted V8 section. VIN E instead of VIN F.  (They LOOK pretty much the same in the manual.  )

Mass Air Flow Sensor burn-off circuit.  They even describe intermittent behavior.

I wonder if it's acting up simply because of disuse.  At least I should be able to figure it out with a DMM. (I pretty good with that).  And the components are right on top front of the engine compartment.

ARRGH