3500 fiero failure

[TurboGTU]

Did you happen to run a 2bar map sensor with a 1bar code in the PCM...also did you use a resistor and Diode on the map sensor? THis could cause havic. Real lean on low VE and TOOO rich on high VE. Or revers...rich and then lean.

I only ask because I saw this in your site...

http://s26.photobucket.com/albums/c134/merlot566jka/?action=view&current=2barmaprig.jpg

Diodes and Ziner diodes are thing of the past.

[davida1_hiwaay_net]

Did you happen to run a 2bar map sensor with a 1bar code ......I only ask because I saw this in your site... <links picture of diagram with resisors and diodes between ECM and MAP signal>

I saw that picture too. I didn't think this car was turbo? Why would it need a 2-bar sensor?

I changed to a 2-bar sensor when adding turbo on two cars. The sensor wiring to the ECM was the same. No resistors or diodes needed. The VE, spark, BPW, and AE had to be changed in the calibration. I don't see how a few resistors will have the same effect as remapping 4 or 5 separate parameters in the calibration.

I don't really see what they were trying to accomplish with that circuit. The orientation of the diode and the voltage divider circuit will cause the MAP signal to read lower MAP pressure than the engine is really seeing; but only when the signal voltage is above some point. Maybe they were trying to defeat an overboost fuel-cut. I can tell you it would not be something I would want to use except as a last resort. If I had all manner of wideband datalogging in place to monitor the engine and see the effect; and I could not change the ECM calibration; I might try it. I would probably change the ECM to one that I can tune before doing this. The MAP value in the ECM is the most important input on speed-density. Altering the signal in this manner will change the spark advance and fuel ratio to a leaner, more advanced state when the boost is highest. Sounds a little backwards?

I would like to know the whole story on this car, what was involved in the engine retrofit. The pictures are nice but I can't find any write-up on it. It looks like lots of time and thought has gone into it. Is the manifold a custom piece?

[IsaacHayes]

He was using 1 bar. The 2bar thing was for another discussion. The custom manifold he made was with the first 3500 plenum that was busted on shipping, he decided to modify it

[Joseph Upson]

I haven't seen the circuit for the MAP sensor but I have one involving a diode that was posted on another site as a way to defeat the overboost engine shut off as was mentioned, involving a simple proceedure installing a diode that would limit the MAP signal voltage to just below the max voltage at which overboost sets so that the ECM never sees it and never shuts the engine down as a result of boost level.

This modification would be needed in the TGP code because the apparent max boost allowed in the code is 10.32 psi although the boost tables reach 190 kpa.

Not sure what to say about the bait and swap tactics experienced with All Pro, they do have two locations within two miles of eachother and that may have something to do with quality of service depending on who you deal with. I know that if they make a mistake in pricing the difference comes out of the sales person's pay check. You could be transferred unknowingly to either location divided by a main road and a railroad track.

[merlot566jka]

1 bar map, no turbo on my car. that schematic i pulled out of another book for another thread...nothing to do with my car. i agree, i wouldnt use that at all either...iw as just sharing what ive learned.

there are write ups all over the place on this, i just didnt combine it into one thread. just search around the fiero forums, and this forum for my name and youll see it all. or you can just pm me and ill shoot ya the details



when i went through the manifold crisis i dealt with scott, who was said to be 'the manager', so i belive its one entity.

[merlot566jka]

lkq said they can get me one for around $550 shipped. i just need to see the damage on my heads to see if i can re use them. if i can, then ill have a set of heads and manifolds to sell.... maybe that will cover some cost here.

[ForcedFirebird]

lkq said they can get me one for around $550 shipped. i just need to see the damage on my heads to see if i can re use them. if i can, then ill have a set of heads and manifolds to sell.... maybe that will cover some cost here.

I would feel bad if I sent you to two places and you have another problem. You don't have a local yard to you? That way you can walk in and talk to a face, rather than over the telly. On the other hand, both dealers are within two hours from me, and can be dealt with locally.

Hope your next experience is better.

[merlot566jka]

well ive used lkq many times...i know they are quality, i have no worries

locally there is nothing. they want in the $1200 range for a 3500. and most have many miles on them

[Joseph Upson]

lkq said they can get me one for around $550 shipped. i just need to see the damage on my heads to see if i can re use them. if i can, then ill have a set of heads and manifolds to sell.... maybe that will cover some cost here.

Have you discussed with All Pro a deal on a replacement? They have a couple of 3900s for $624 and technically speaking except for the intake manifold issue I really don't believe the engine failure is a result of a defective engine, in which case it wouldn't make them a bad company to deal with. It's important to deal with the same person everytime and touch all basis, and yes shippers more times than not are responsible for the damage present upon arrival. I'm still pissed about the empty box UPS delivered to my front door knowing full well it was empty having lost a complete passenger side axle with intermediate shaft for the 6 speed transmission.

Since you already have a 3500 installed the 3900 would be a piece of cake, especially since I've already mapped it out, and it shouldn't require modification to the trunk area since you are using a Fiero transmission. I needed to make a small notch because of the exhaust manifolds I used. You might as well go whole hog, you're almost there anyway.

[davida1_hiwaay_net]

Off topic but relevant - A major parcel shipper (who happen to drive brown trucks) delivered a 'box' to a job site which was little more than one flap and the side of the box containing the address label. This was partially wrapped around the severaly damaged and incomplete part I had ordered. There was about half a roll of clear packing tape wrapped around it with one mangled, bent hydraulic valve cartridge protruding through.

We filed a claim and it was denied because part was "improperly packaged" by the shipper. Box was new, double-wall box and part was in a foam block. All this had been lost by shipping company. Yet it was OUR fault.

Then same shipping co. delivered an empty box that had contained a $3000 hydraulic motor. The box had been opened and re-taped and then come open again. This time they paid for the motor. Two weeks later they "found" the motor, delivered it, and wanted their money back! It was rusty, protective caps were missing, and there was dirt all down in the ports. Looked like it had been used to chock the wheels of a truck parked in a gravel parking lot! I beleive our management told them to keep it!

OK sorry! Rant over. :-)

[mcgavinz26]

I know this is one big "duh", but keep an eye on craigslist. I just got my 3500 for $500, only missing the alternator and ACC, 12k miles. Guy was asking $600, I offered $450, and the rest is history.

[merlot566jka]

Have you discussed with All Pro a deal on a replacement? They have a couple of 3900s for $624 and technically speaking except for the intake manifold issue I really don't believe the engine failure is a result of a defective engine, in which case it wouldn't make them a bad company to deal with. It's important to deal with the same person everytime and touch all basis, and yes shippers more times than not are responsible for the damage present upon arrival. I'm still pissed about the empty box UPS delivered to my front door knowing full well it was empty having lost a complete passenger side axle with intermediate shaft for the 6 speed transmission.

Since you already have a 3500 installed the 3900 would be a piece of cake, especially since I've already mapped it out, and it shouldn't require modification to the trunk area since you are using a Fiero transmission. I needed to make a small notch because of the exhaust manifolds I used. You might as well go whole hog, you're almost there anyway.

nope, havent tried to talk to them about a replacement. they just said well refund you your money.... ill call them tomorrow (if theyre open) or monday and see what i get out of them.

my headers wont work with the 3900, my injectors arent big enough, and i dont have a returnless fuel set up. i belive the alt and a/c are different as well, which brings more issues. plus my 3500 has a nice cam that may be re-useable in another 3500, i doubt i can use that cam in a 3900.

ill look into it tho...it may be worth it. its going to be a month or two before i can afford another engine.

[Lilchief]

Merlot: Have you found the problem and it's cause yet?

[merlot566jka]

nope, havent had time to work on it. also havent found the extra cash to even get it towed to work so i can pull it apart.

im sure its a piston or rod failure due to thin oil

[Joseph Upson]

nope, havent tried to talk to them about a replacement. they just said well refund you your money.... ill call them tomorrow (if theyre open) or monday and see what i get out of them.

my headers wont work with the 3900, my injectors arent big enough, and i dont have a returnless fuel set up. i belive the alt and a/c are different as well, which brings more issues. plus my 3500 has a nice cam that may be re-useable in another 3500, i doubt i can use that cam in a 3900.

ill look into it tho...it may be worth it. its going to be a month or two before i can afford another engine.

Correct on the headers and you would need a returnless fuel system which isn't difficult to make, however you woudln't be able to use your current injectors even if they did flow enough although a returnless fuel system would allow you to use the stock injectors with the engine. I haven't attempted it yet but using my extra 3900 intake I noted it may be possible to use the 3400 rail and injectors after some grinding on the runner, the 3900 intake ports are so large that they are closer to the injectors and a little clearance trouble comes into play using the 3400 rail.

You are also correct about the alternator and A/C compressor although I'm not sure the alt issue is anything more than more grooves in the pulley and amp output since they both bolt in the same way.

You wouldn't be able to use the cam either as stated without being modified in which case it would be much easier to send the stocker out for a regrind. If you can weld, the store has exh flanges for the 3900. I have a set along with some 14 ga 1 3/4" mandrel bends. At some point I'll setup the extra motor and maybe build a header setup.

You may not have any cylinder head damage from throwing the rod since usually it's slammed into the block rail when the throw comes around and makes contact.