Welcome to the all new Geo Metro Forum. We hope you enjoy your visit.You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are features you can't use and images you can't see. Registration is simple, fast, and completely free. If you're already a member please log in to your account to access all of our features: Join our community! |
- Pages:
- 1
- 2
| Frustrating Backfire in T-Body on Rebuild; Backfire | |
|---|---|
| Tweet Topic Started: Mar 15 2015, 09:59 PM (1,259 Views) | |
| Hanuman | Mar 18 2015, 04:22 AM Post #16 |
|
"The Almighty Grounds Cleaner"
![]()
|
there is a reason why they call me ..........."The Almighty Grounds Cleaner" if when i dont help......i still help
|
![]() |
|
| CaptainMetro | Mar 19 2015, 01:17 AM Post #17 |
![]()
|
How many problems have been fixed by cleaning grounds on GMF? |
![]() |
|
| Hanuman | Mar 19 2015, 04:50 PM Post #18 |
|
"The Almighty Grounds Cleaner"
![]()
|
let me put it this way: the ground on the back of the intake serves just about all of the engine sensors and controls, the ecm, and the fuel pump. this location only grounds to the intake manifold......it still must ground to the head, then to the block, then the tranny case, then through the negative tranny to battery ground connection and lastly from negative battery cable to negative battery post. even a slight bit of corrosion on the grounding system increases the electrical resistance of all sensors involved, this effects the signal going to the computer...signals will be weaker, value will be off. you cannot test any of the electrical system if the values are off in the first place. every single metro that has come to my house has seen improvement from cleaning the grounding and positive systems. most of the time the actual "failed component" worked properly after cleaning the grounds. to answer your question as to how many on the forum? many times. |
![]() |
|
| CaptainMetro | Mar 20 2015, 01:11 AM Post #19 |
![]()
|
That's good to know. |
![]() |
|
| BreakingBolts | Dec 10 2016, 02:19 PM Post #20 |
|
Fresh Fish
![]() ![]() ![]()
|
Hello and Many Thanks, Newbie to this form, new to metros(falling in love very fast), and I am working on troubleshooting a similar problem I think. I swapped the head from a decent running 1990 to my 1994(the reason being the 94 had burned out valves but has much better running gear and the body isnt rotting in half). The only components swapped were: head with valves, cam, coolant fitting w/sensors. -Idles great but surges/pulses with throttle increase. bogs down when a lot of throttle applied rapidly. - back fires occasionally through intake. -overcomes surging after approx ten seconds but only if throttle is ramped up slowly.(still backfires every ten-20 seconds) -Compression appears to be good 1.170 2. 175 3. 170 (WOT) -vacuum system appears intact and up to par. -tps is set to 1.04 at 3.5mm (warm) -Cam is set to the 80 mark TDC on belt gear(had also tried the 60 with same result) -have adjusted from 5 deg TDC 8 deg TDC ign(jumper in place). currently at 6 deg(all have same result) -None of these problems had occured with the 1990. the 1994 wasnt running well when purchased(no idle and very little power,1&3 were burned out pretty bad) I have reviewed and double checked timing(s) and sensor values about 5 times. also traced through Vac system and cleaned EGR The reason for swap was to rebuild the 1990 while using the 1994 so I just wanted it operational but its not going so great and I am ready to swap back.. Not sure about the pedigree on either as I have only had the 1994 for about a month with little to no background info. Any ideas? I will be checking the distributor issue as well but figured id throw it out there as I am sitting now. Many thanks again for your help. Breaking Bolts Edited by BreakingBolts, Dec 10 2016, 02:28 PM.
|
![]() |
|
| ptcapboy | Dec 10 2016, 05:36 PM Post #21 |
![]()
|
did you remove the intake manifold and throttle body from the 90 head and use the intake from your 94? also 94 was a transition year with some cars being advanced emissions and the earlier ones standard-I believe you can tell by seeing if there is a black box like thing on your throttle body-no black box, it's standard emissions-and yes, use your distributer of your 94 |
![]() |
|
| freegeo | Dec 11 2016, 11:28 AM Post #22 |
![]()
|
Have you checked the EGR valve to make sure it is not stuck open? |
![]() |
|
| Hanuman | Dec 13 2016, 08:32 AM Post #23 |
|
"The Almighty Grounds Cleaner"
![]()
|
To back fire through the intake one of two things must happen: A spark plug must fire during the intake stroke..... Combustion must go around a intake valve to enter the intake manifold...... For the plug to fire during the intake stroke means it's nearly 180° out of time. Also means it won't start and run. You can't install the distributor backwards on these cars. I'm guessing you have a damaged valve spring, or a bad lifter....something effecting the proper closing and seal of a intake valve.....this may not be apparent while crank8ng or doing a compression test...it may only happ3n at engine speeds at or above idle. I would say check routing of plug wires....but I'm sure you would have noticed it the car was running on one cylinder, not 3....lol Check for moisture under the distributor cap....this can cause the spark to jump a post. Also check the distributor cap vent...make sure it is free and clear. There is a slim possibility that a backfire in your exhaust could go through the egr valve and into the intake manifold.....but that's unheard of. A stuck open egr would give you a seriosly rough idle....if it stay3d running at all. |
![]() |
|
| 1 user reading this topic (1 Guest and 0 Anonymous) | |
| « Previous Topic · Engine Tech & Diagnostics · Next Topic » |
- Pages:
- 1
- 2


Welcome to the all new Geo Metro Forum. We hope you enjoy your visit.

gla we could help






![]](http://z3.ifrm.com/static/1/pip_r.png)
9:29 AM Jul 11