No CEL, engine cranks but won't start, bad ECU?

[nfpgasmask]

Hi folks, I'm having an issue with my 91 Isuzu Trooper, 3.4 swap from a 95 Firebird, bored out intake and a 4.3 Throttle Body with 4.3 injectors.

The start of the problem was that my cap and rotor came off while driving. Once I figured out that problem, I jumped the ALDL to reset my idle and TPS voltage, and during that process something fried. I thought it was my wiring harness, so I pulled it, repaired and reconditioned the whole thing. Tonight I put it back in, and I also replaced the MAP and TPS. Same problem. No check engine light illuminating at all when the key is turned to the 'ON' position and she cranks but won't start.

I've checked all my fuses 3 times, and now I can only think it must be a fried ECU. Any suggestions?

Thanks,

Bart

[86FieroSEv6]

Sure you checked the fuses . . . . but did you actually take a meter to the power and ground circuits at the ECM connector/s?!?

[60dgrzbelow0]

You have not mentioned which ECU you are using in your Jeep... but if you converted using the wiring harness from the 93-95 3.4L L-32 Engine for the GM F-Body Carline Series... you will find some inexpensive solace with the ECUs available on eBay as of this very posting... it will be important to pick the one designed for either an automatic or manual transmission. Hope this helps... after all at these prices...even if it turns out not to be the problem... you will have eliminated the largest of the variable things that can go wrong... Please remember to Beware...and to ask whether the ECU you pick is coming out of any salvage vehicle from the Katrina Disaster... They are well made...but will never work properly after submergence in the brackish waters mixed in with a liberal dose of the water from the Gulf of Mexico that submerged New Orleans...and everything on wheels along with it...

http://shop.ebay.com/i.html?_kw=camaro&_kw=3.4l&_kw=ecu

[bob442]

capaciter?

[nfpgasmask]

Sure you checked the fuses . . . . but did you actually take a meter to the power and ground circuits at the ECM connector/s?!?

I'm gonna check this tomorrow with my meter.

You have not mentioned which ECU you are using in your Jeep...

Funny, because I never mentioned Jeep. I have a 91 Isuzu Trooper with a 3.4 motor out of a 95 Firebird. The ECU is the original 2.8 ECU that came with the Trooper.

I have a replacement ECU on the way from eBay.

Thanks - Bart

[60dgrzbelow0]

My bad... Isuzu Trooper... Generic for Jeep... Got it. Thanks for keeping me on my toes.

[nfpgasmask]

My bad... Isuzu Trooper... Generic for Jeep... Got it. Thanks for keeping me on my toes.

First you stick the knife in, then you twist it, nice! JK! Jeeps are Jeeps, never insult an Isuzu guy by calling his TROOPER a Jeep. LOL.

Bart

[pocket-rocket]

I'm sorry, Bob, but I had to laugh at the whole Jeep thing. Thanks for tickling my funny bone first thing this AM As for nfp's comment about never insult an Isuzu guy by calling his truck a Jeep, that's icing on the cake there. On the Ranger boards guys consider Jeeps "bolt on off road kits for dummies" as about 3/4 of the Ranger guys fabricate this or retrofit that from other vehicles.

[nfpgasmask]

Yeah, I really have nothing against Heeps, but that doesn't mean I won't defend my Trooper when someone accidentally makes fun of it.

So, Looks like I have a bad connection to the ECU, be it a fuse, fusible link, or bad ground. If all that checks out I guess it could be a fried ECU. I hope to get to the bottom of this soon. Yesterday I did find some bad fusible links, so now I need to find a replacement for those.

Bart

[60dgrzbelow0]

First you stick the knife in, then you twist it, nice! JK! Jeeps are Jeeps, never insult an Isuzu guy by calling his TROOPER a Jeep. LOL.

Bart

NFP...

Actually... I wound up unintentionally adding insult to injury TWICE ...so I guess you'll have to take a swing at my chin for my ignorance. What I MEANT to say was that I generally group similar OTR vehicles into the "GP" category ...which is where the whole "Jeep" expression came from back in Dubya Dubya Too describing "Vehicles" General Purpose". . You should know that its well out of character for me to intentionally render anyone insults in here when our collective motivation is to help one another get our wheels back on the road...regardless of what happens to be above them. Forgive me ...Please ..and likewise ...accept my profound apologies for not knowing the distinctions to be made here...or more importantly, the very competitive feelings that Isuzu owners hold to jealousy guard them.

[nfpgasmask]

Its all in good fun, right? No need to apologize, and I much appreciate all the help. It was just that you "struck a cord" with me...this is my blog:

http://notajeep.blogspot.com

The whole idea for my blog came from the fact that lots of people use the word Jeep as a generic term for 4x4, much like when we say "Kleenex" when we should say "facial tissue", and "Q-tip" when we should say "cotton swab".

Bart