Engine miss??? Big time frustrated...

[SolidState]

if it isn't the sensor, it could be a short in a wire somewhere...

is this the MTX conversion car?

 

[Mike93]

if it isn't the sensor, it could be a short in a wire somewhere...

is this the MTX conversion car?

Yes, it is the conversion car. As far as the wire harnes goes, after the engine/trans was removed I wrapped up the wire harness in electrical tape and hid as much of the wiring as possible...I don't know if you were implying that it may be damaged or not?

 

[TrueBlue]

Need help with it Mike? Let me know.

 

[RJ-92]

Need help with it Mike? Let me know.

Same here bro. I got plenty of extra gas laying around and would have no problem carelessly misplacing a cigarette butt.

 

[Mike93]

Tom and Ron...thanks for the offers, I'll keep that in my for if/when get to work on this thing.

While I'm here...does anyone have an atx computer they'd sell cheap or let me borrow??? I'll cover all shipping Going on the theory of faulty electronics, I'm wondering if when I had the motor out when I sprayed the entire engine compartment down with foaming engine cleaner if that got into elctrical connectors and the computer??? Possibly causing something to short out or the like???

 

[SonicRiot]

Set a code by unplugging the crank position sensor and trying to fire up the car. Or pull the ECT connector and drive the car. Or an O2 sensor. If it sets a code, your computer might be fine. Its not a great test, but it's an idea of how the computer's self-diagnostic capabilities are working.

 

[TrueBlue]

Same here bro. I got plenty of extra gas laying around and would have no problem carelessly misplacing a cigarette butt.

I'll bring the cigarettes.

 

[Paul]

Try this. Jack up the right front, jackstand please, then crawl under and take a hard look at the coolant pump pully where the CPS cable goese near it. if "someone" did'nt put the rubber grommet back in the timming case cover properly it can rub on the coolant pump pully causing a grounding out situation that will make the motor run like shit, buck & and stall. It will also make the thing BUCK really bad. It will be good then bad. The remidy is a new CPS. Too bad. Take a look. I'm not BSsen ya.

 

[Mike93]

Another update: swapped out the computer for another H3Z and nothing changed.

A rebuild wont help a driveability issue if it's caused by a bad sensoring or wiring...

rangerj had a really nice write up on ignition system diagnosis that helped me pinpoint an intermittantly bad crank position sensor in a matter of minutes, but I can't find it.

As for the MAF, I will try to find my notes on pin-out diagnosis... I know it's around here somewhere.

A scope would really be helpful for you here. Being able to watch the nuances of misfires and stumbles on a graphing screen is really helpful, but the equipment is super expensive and it takes some experience to know what's going on. Sometimes, this is better left to a shop that has that equipment.

For now, keep plugging. I'll keep looking for notes.

I just sent rangerj a pm aout the write up you mentioned...hopefully he still has that. I'll have to track down a reputable shop oor find someone local who has knowledge of the scope.

I'll say again, I don't think this is a sensor/electrical issue.

I say tear it down. And, while you are at it, replace the main wiring harness.

I have a line on a wire harness and it may come down to pulling the engine and swapping this. There are a couple things I had wanted to do and having the engine out would make it easier.

Anyone have any thoughts to the use of foaming engine cleaner on exposed (unplugged) electrical connectors??? Wondering if this could be an issue with the wire harness...

Thanks, Mike

 

[TrueBlue]

Mike, before we put the motor in mine I foamy brighted the bay - I did cover most of the connectors, but there were a few that got coated in foam. No problems from that.

Do you have a voltmeter? You can use mine if you need to.

 

[rangerj]

Check your inbox Mike. For anyone else interested the write-up referred to above is easily found by searching "testing the DIS". Given that this is a "swap" check your placement of the wires on the coil packs and the plugs. There is a referrence source out there that shows the wrong placement order.

 

[stevensclan5]

first of all I feel your frustration. I had a similar situation and replaced everything but the Coil pack and low and behold it was the coil pack, the motor felt like it was be strangled at WOT and would smoke dark (fuel). When I went back then and SCANNED MY CODES it gave me a weird number like front ign pack or something. Go to shotimes.com to d/l your codes. you had a problem with timing on the #1 cylinder. did you have the same thing on the #4 cyl? if so my bet is on coil pck. The back pressure BO leads me to think you have a timing problem as well. I doubt its the cams unless you messed with them. Line the timing marks up level with the head at the 3 and 9 o'clock. Timing belt is the likely culprit though. CPS i doubt, they usually just go out and the car comes home on a hook. Scan you codes first and correct what you find. O2 sensors will show up then if bad, as well as injectors. double check your butterfly vacuum actuators are both coming open at 4K. Good luck

 

[Mike93]

Check your inbox Mike. For anyone else interested the write-up referred to above is easily found by searching "testing the DIS". Given that this is a "swap" check your placement of the wires on the coil packs and the plugs. There is a referrence source out there that shows the wrong placement order.

Rangerj- I did find your write ups on ignition system diagnosis..however I haven't had time this week to work on the car. As far as wiring goes for the coil, I know what you're talking about as my Chiltons has the incorrect sequence...so I'm 100% sure the wires are correctly placed on the coil.

first of all I feel your frustration. I had a similar situation and replaced everything but the Coil pack and low and behold it was the coil pack, the motor felt like it was be strangled at WOT and would smoke dark (fuel). When I went back then and SCANNED MY CODES it gave me a weird number like front ign pack or something. Go to shotimes.com to d/l your codes. you had a problem with timing on the #1 cylinder. did you have the same thing on the #4 cyl? if so my bet is on coil pck. The back pressure BO leads me to think you have a timing problem as well. I doubt its the cams unless you messed with them. Line the timing marks up level with the head at the 3 and 9 o'clock. Timing belt is the likely culprit though. CPS i doubt, they usually just go out and the car comes home on a hook. Scan you codes first and correct what you find. O2 sensors will show up then if bad, as well as injectors. double check your butterfly vacuum actuators are both coming open at 4K. Good luck.

I've tried a few different coil packs that came from working vehicles. I have also checked codes and no codes were thrown. Yes, I did have a problem with #1 cylinder...but what I have come to realize through my weekly pulling of plugs is that this issue seems to come and go with different cylinders. One bank may be fouled out...I'll replace plugs...pull them later and it's the other bank that'll be fouled...or maybe just one plug...it's wierd. I haven't touched anything with the cams, and timing belt lines are lined up correctly. Secondaries are opening at 4K. Thanks for the replies. I'm still digging...

 

[SonicRiot]

What do you mean by "fouled out"?

 

[Mike93]

What do you mean by "fouled out"?

Plugs are completely black...like it has been running incredibly rich and/or having zero spark.

 

[SonicRiot]

Hm. Interesting. I'm sure you're posted this or looked into it, but have you considered a coil pack?

 

[Mike93]

Hm. Interesting. I'm sure you're posted this or looked into it, but have you considered a coil pack?

Post #53 above...second paragraph . Yes, I have tried different coil packs...but still no workie.

 

[coltsho]

Slow between 4000 to rev limit

In reguards to the engine reving to just over 4000 rpms and then slowing til the rev limiter. My 89 does the same thing. I just had a valve job done so all top end gaskets are new as well as the crank sensor, timing belt and cam sensor. when I put the engine back together the it did it from the get go and even the tach didn't work. I fixed the tach problem by getting a new cam sensor harness. and I noticed on the crank sensor had a groove between where the pickups on the crankshaft timing gear had been rubbing. when i put the new sensor on i gapped it 30 thousandths but when i turned the engine the other two pieces on it were then only gapped 20 thousandths.

since i got the car i couldn't read any codes from the computer, this makes me think it is bad (plus no support bracket behind the glove box). The cam sensor may have shorted it also.

Which should I replace first, the computer or the crankshaft timing gear?

 

[Paul]

I recieved 2 sho's that had ill-installed CPS sensors. If you jack up the car on the right frt. (use a stand) Crawl under behind the frt wheel and look up and see if the coolant pump pully is rubbing on the CPS harness and cut into it. If the CPS is not installed proper, with the rubber grommet fully pushed into the middle section of the timing cover, it can rub on the edge of the coolant pump pully causing problems that really suck.

 

[SonicRiot]

Mike, have you been able to set a code on your car at all?